# F8F Bearcat rate of climb



## DCG2U (May 30, 2013)

Greetings everyone,

I searched everywhere around the web to find the Bearcat best rate of climb (any variant) because some say it had the fastest rate of climb of any piston fighter at 6300 ft/min (32 m/s) while others say it could only achieve around 4300 ft/min (23 m/s). Here are my sources:

http://en.wikipedia.org/wiki/Grumman_F8F_Bearcat


Quote

An unmodified production F8F-1 set a 1946 time-to-climb record (after a run of 115 ft/35 m) of 10,000 ft (3,048 m) in 94 seconds (6,383 fpm). The Bearcat held this record for 10 years until it was broken by a modern jet fighter (which still could not match the Bearcat's short takeoff distance).





http://www.aviastar.org/comments/comments.php?order=0&aircraft=0507

Great discussion about people that actually flew a Bearcat.


http://www.warbirdaeropress.com/articles/HotestCats/HotCats.htm

http://www.warbirdsforum.com/topic/147-grumman-f8f-bearcat-climb-rate/

http://www.angelfire.com/space/grumman/aircraft/bearcat.html

http://www.aer.ita.br/~bmattos/mundo/country/usa/grumman_bearcat.html

http://historywarsweapons.com/f8f-bearcat/

http://www.aviation-history.com/grumman/f8f.html


http://www.wwiiaircraftperformance.org/F8F/F8F-2_Standard_Aircraft_Characteristics.pdf


This link is the real performance charts of the F8F Bearcat.



I love this aircraft a lot but just want to know if legends about it are true.

Thank you.


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## tomo pauk (May 31, 2013)

Something might be done with cropped links?


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## GregP (May 31, 2013)

I'll look at a pilot's manual this coming weekend and see what it says.


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## DCG2U (May 31, 2013)

Fixed the links, sorry I didn't notice.


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## GregP (Jun 1, 2013)

It happens to all of us once in awhile. Thanks for the fix.


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## krieghund (Jun 1, 2013)

The F8F manual I posted a while back is here: http://www.ww2aircraft.net/forum/other-mechanical-systems-tech/manual-index-american-36322.html and also some USN charts of the F8F-1 and -2. Enjoy


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## Readie (Jun 1, 2013)

The Bearcat I watched at West Malling in the early 1980's rate of climb can be summed up in one word...Phenomenal.
Cheers
John


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## norab (Jun 1, 2013)

not something I can quantify, but long ago when the big annual EAA fly-in was still at Rockford, I saw a race between a bearcat and a P-51 from a standing start. The bearcat took off, retracted gear, circled the field, and was making a simulated firing run on the mustang before the P-51's wheels even left the ground. It was impressive as hell


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## DCG2U (Jun 1, 2013)

krieghund said:


> The F8F manual I posted a while back is here: http://www.ww2aircraft.net/forum/other-mechanical-systems-tech/manual-index-american-36322.html and also some USN charts of the F8F-1 and -2. Enjoy



Judging by these performance sheets, there is no way that any F8F Bearcat could climb at 6300 ft/min. 4000 ft/min seems more accurate. Not that I am doubting your real life accounts guys but I need some data in order to prove it. From what I've read in the forums (and other sources), the record established by the Bearcat in 1946 was an unmodified F8F-1, 50% fuel, combat armor, guns but no ammo but according to krieghund performance charts, there's no way it could climb 6000 ft in 90 seconds.


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## FLYBOYJ (Jun 1, 2013)

DCG2U said:


> Judging by these performance sheets, there is no way that any F8F Bearcat could climb at 6300 ft/min. 4000 ft/min seems more accurate. Not that I am doubting your real life accounts guys but I need some data in order to prove it. From what I've read in the forums (and other sources), the record established by the Bearcat in 1946 was an unmodified F8F-1, 50% fuel, combat armor, guns but no ammo but according to krieghund performance charts, there's no way it could climb 6000 ft in 90 seconds.


One of our member's father was the pilot who flew this aircraft, let's see if he chimes in on this one...


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## CORSNING (Jun 1, 2013)

Well, if you extend the graph on the F8F-1 it shows an inital climb rate of about 4,735 fpm. Profile Publications shows the same 2,400 hp. at 1,000 ft. and adds that war emergency between 9,500 - 16,600 ft. was 2,700 hp. Test weight being 9,334 lbs. would give it a power loading of 3.457 lbs./hp. The Bearcat was a relatively small plane to a lot of its contemporaries AND keep in mind the PW-2800 was an engine that could be pushed well past the military established limits and keep on ticking. Anybody that knows what I'm talking about jump in anytime and give me some help here.

OK, I know this is off topic sort of, I have been researching the Ki.44-III. It was suppose to have 2,000 hp. Increased wing area (204 sq.ft.). Combat (interceptor) weight of 5,357 lbs. That's 2.6785 lbs./hp. I wonder how fast that bad boy climbed.? I also wonder how the increased wing area affected handling.?


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## CORSNING (Jun 1, 2013)

there's no way it could climb 6000 ft in 90 seconds.[/QUOTE] Correct that DCG2U. Go on now.


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## FLYBOYJ (Jun 1, 2013)

http://www.ww2aircraft.net/forum/av...s-grumman-f8f-bearcat-33022-5.html#post911193


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## CORSNING (Jun 1, 2013)

"theater", why are we having this discussion again? Nice FLYBOY. You the man Joe.


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## GregP (Jun 2, 2013)

Went to the Museum today and found the Erection and Maintenance Manual and the Parts Manual, but couldn't locate the Pilot's Manual, and Steve Hinmton left for another airshow before I could catch him. It's have to wait another week or so.


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## DCG2U (Jun 2, 2013)

CORSNING said:


> there's no way it could climb 6000 ft in 90 seconds.


 Correct that DCG2U. Go on now.[/QUOTE]

Just took a look at FLYBOYJ's link and I stand corrected. Sorry, didn't look through the whole thread when I tried to find info about its rate of climb. I don't want to be picky but is there's any book/information accessible to everyone? Not that I doubt him, I just want to see if there is more ''official'' information about its rate of climb.

Thanks again.


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## DCG2U (Jun 2, 2013)

CORSNING said:


> there's no way it could climb 6000 ft in 90 seconds. Correct that DCG2U. Go on now.



Just took a look at FLYBOYJ's link and I stand corrected. Sorry, didn't look through the whole thread when I tried to find info about its rate of climb. I don't want to be picky but is there's any book/information accessible to everyone? Not that I doubt him, I just want to see if there is more ''official'' information about its rate of climb.

Thanks again.


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## krieghund (Jun 2, 2013)

Here is the Take-off, climb and landing chart from the FM Sorry it is a bit blurry. Also remember that the climb is usually scheduled at Military Power and not WEP.


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## CORSNING (Jun 2, 2013)

DCG2U,

You posted it twice and still didn't get it: 6000 ft. in 90 seconds is 4,000 fpm avg. A time that even a fully loaded F8F could accomplish from sea level. I'm just messing with you man, I figured you meant 6,000 meters.


krieghund,
I forgot to tell you thanks for the charts/graphs and information.


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## DCG2U (Jun 4, 2013)

CORSNING said:


> DCG2U,
> 
> You posted it twice and still didn't get it: 6000 ft. in 90 seconds is 4,000 fpm avg. A time that even a fully loaded F8F could accomplish from sea level. I'm just messing with you man, I figured you meant 6,000 meters.
> 
> ...


 
Oops, I meant 10 000 ft in 90 seconds, which is roughly 3000 meters. But yeah I get it, this could achieve such feats, I was just a little skeptical.


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## Neil Stirling (Jun 9, 2013)

Question: Did the Bearcat actually climb to 10,000ft, therefore passing through 9,209ft or did it climb to 10,790ft?

Cleveland Airport is 791 ft above sea level, this link seems to indicate a time to climb to 10,000ft http://www.ww2aircraft.net/forum/av...s-grumman-f8f-bearcat-33022-5.html#post911193 

Neil.


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## davparlr (Jun 9, 2013)

I have to level the playing field here before everybody gets googly eyed over the F8F. There are some of points I need to make.

1.	The Navy, and everybody else, loves to compare its late model prop planes, F8F-1/2, F4U-4/5, to the P-51B/D. However, the P-51B/D were operational at the end of 1943 when they were desperately needed in the war, not in mid-1945 when the war was basically over. The Navy planes were about a generation and a half past the P-51B/D. By mid-1945, the AAF was pretty well washing its hands of propeller driven fighters having cancelled the powerful and impressively performing P-72. Only the P/F-82 continued in development, mainly due to its long range and all weather potential. The AF was only interested in jet fighters. The Navy, on the other hand, leery of the weak jet engines available, needed to keep their prop fighters operational for another four plus years when jet performance and carrier designs helped make carrier jets viable (although their performance was way below the performance required to fight the next air-air war, so they basically set it out). The AF had zero interest in any performance records for prop aircraft. Jets, yes.

2.	I noticed the famous flight to 10k ft. in 90 seconds for the F8F was made in November. It would be interesting to know what ambient temperature was. Also, there were several comments about the record being held until the F-16. Ridiculous, the T-38 set a record climb to 40k in 100 seconds in 1962, the F4 beat that in one month, both well before the advent of the F-16.

3.	The contemporary to the Navy props was the P-51H, something the Navy never seemed to compare their late fighters to.

4.	The P-51s used in most comparisons seem to be lower performance ones using 67” boost instead of the 72-75” boost authorized post May, 1944. Also, they tend to use data with heavy loads of fuel which it is capable of carrying. This tends to not be a factor in comparisons to Navy aircraft as they also tend to carry a lot of fuel. 

So here is my comparisons of the P-51B (selected because I have flt test data, its armament is similar to the F8F, and it performs a bit better than the D), the P-51H, F8F-1 (the -2 did not become operational until 1948 ). Data will be airspeed in mph, and climb in ft/min for each altitude level. P-51B will be at 75” boost tested.
150 Grade Fuel



*SL*
P-51B 386 4420
P-51H 413 5120
F8F 382 4600

*5k*
P-51B 410 4420
p-51H  434 4280
F8F  410 4000 

*10k*
P-51B 420 3900
P-51H  445 3600
F8F 400 3300

*15k*
P-51B 428 3820
P-51H 440 3650
F8F 405 3295

*20k*
P-51B 442 3200 
P-51H 463 3100
F8F 420 2600

*25k *
P-51B  440 2400
P-51H 466 2350
F8F 420 2000

*30k*
P-51B 430 1700
P-51H 448 1700
F8F 410 1250


So, when the F8F-1 is compared to contemporary powered P-51B or the contemporary P-51H it does not seem to be overly impressive, a good as a performer as it is.


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## GregP (Jun 9, 2013)

I think you're comparing an F8F-1 at Military power (perhaps even Normal power?) and with racks mounted with a clean P-51 at WER power. All of us who regularly see the Bearcat and P-51 fly KNOW which one is hotter, but we still love the Mustang.

Again this weekend, Steve Hinton was not there. He was busy doing a first flight on a newly restored F7F Tigercat. I asked another Bearcat pilot and he said the F8F-2 was around 4,500 fpm at sea level clean, at Military power and had never seen the specs for a WER climb but had done one from a standing start and had easily seen 5,300+ fpm off the runway. He was a normal peacetime weight ... probably a bit lighter than a wartime loadout.

Most Bearcat owners don't do a WER takeoff and climbout very often.

Naturally, I'll continue to look for the F8F-2 -1 pilot's manual for a reference other than a current pilot.


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## davparlr (Jun 10, 2013)

GregP said:


> I think you're comparing an F8F-1 at Military power (perhaps even Normal power?) and with racks mounted with a clean P-51 at WER power. All of us who regularly see the Bearcat and P-51 fly KNOW which one is hotter, but we still love the Mustang.


You may be right but the chart I used, which is the same as the F8F-1 charts above, indicate that power used is "Combat” (which also shows the F8F-1 combat power as 2380 hp at SL, Mil power is shown as 2100 hp at 3400’). I did note that this was with racks installed and it shows a correction to a “clean aircraft” was airspeed of 394 mph at SL and a max speed of 434 mph at 19.8k ft. So an eyeballing correction to the chart is below. This could possibly affect climb but insignificantly so. 


SL
P-51B 386 4420
P-51H 413 5120
F8F-1 394 4600

5k
P-51B 410 4420
p-51H 434 4280
F8F 422 4000 

10k
P-51B 420 3900
P-51H 445 3600
F8F 412 3300

15k
P-51B 428 3820
P-51H 440 3650
F8F 418 3295

20k
P-51B 442 3200 
P-51H 463 3100
F8F 434 2600

25k 
P-51B 440 2400
P-51H 466 2350
F8F 433 2000

30k
P-51B 430 1700
P-51H 448 1700
F8F 424 1250

I suspect that it is really rare for these planes to be flown at WEP. I suspect that none of the flying P-51Bs have been flown at 75” boost, which was approved in WWII. And how many P-51Hs are even flying, much less at 90” boost?

I still don’t think the F8F-1 was significantly better than the P-51B in climb and airspeed at the end of the war and certainly not better than the P-51H (whose numbers above are conservative).


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## GregP (Jun 10, 2013)

It may not have been better in speed right at the end of the war, but was all over it in climb, acceleration, and was better in roll. The F8F can be airborne and quite a way off when the P-51 is just lifting off. When you see them fly side by side, the F8F is a better performer.

Now the F8F is about a 6.3-g fighter at combat weight while the P-51 is an 8-g fighter at 8,000 pounds. But if you load the P-51 to 10,000 pounds as it was on many missions, it is a 6.4-g airplane. I love them both but if I had to get into a fight in one or the other, I'd take an F8F any day based on handling, acceleration, and general maneuverability.


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## CORSNING (Jun 12, 2013)

I agree with Greg, unless the battle is more than 500 mls. from home......I'm just saying, That was the reason the Mustangs Allison/Merlin were so valuable.


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## GregP (Jun 12, 2013)

Yah, long range requirement? P-51 any day, unless you'd go for a P-82 ...


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## davparlr (Jun 15, 2013)

> you see them fly side by side, the F8F is a better performer.
> 
> I'd take an F8F any day based on handling, acceleration, and general maneuverability.


 
Hi, Greg,
I have a sneaky suspicion that all the comparisons you have been exposed to were P-51Ds to F8F-2s, a 1944 aircraft to a 1948 aircraft, a couple of generations apart. I think that if you compared a 2200+ hp, 9200 lb P-51H to a 2300 hp, 9200 lb F8F-1, both 1945 aircraft, you would find that the much cleaner P-51H (which means it uses less power at any given airspeed) could out accelerate the F8F-1 at any given airspeed although at lower airspeeds it would be very close. I also think the climbing ability of the P-51H is rather impressive as is the F8F-1. And with a 30 mph airspeed advantage above 10k, the P-51H has all the offensive advantages there.

I just went through the AF Museum at W-P. Do you guys do any work with them? They are upgrading but I missed some aircraft like the P-59, which you are trying to get off the ground, and no P-80A (they may not exist), but did have a P-80C. Also, I did not see the only aircraft responsible for a victory in a Soviet-West Cold War confrontation, the historically great and under appreciated C-54 (and their crews and ops people). I could have missed some things because it is so big and I had limited time (wife was at daughter's home and I had the car). Museum operation has been impacted by sequester.


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## GregP (Jun 16, 2013)

No P-51H could outclimb any Bearcat. The P-51H was faster and longer-ranged, but not as maneuverable. Pure fighter? The Bearcat has no equal that I am aware of in the piston family. Of course, they didn't make very many, either. Everyone was gaga over jets. Sitting in one makes me want to comit aviation in it.

We have done some work with many other museums, but not specifically Wright-Patersion as far as I know. They DO have a nice collection. Right now, we're missing two of ours. The Zero is in Japan and the P-47 is in Idaho. Hopefully both back in a few months.

Come out and see us again sometime, Dave.


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## Shortround6 (Jun 17, 2013)

GregP said:


> No P-51H could outclimb any Bearcat. The P-51H was faster and longer-ranged, but not as maneuverable. Pure fighter? .



Out climb?

http://www.wwiiaircraftperformance.org/mustang/p-51h-booklet-pg15.jpg

http://www.wwiiaircraftperformance.org/mustang/F-51H_Mustang_SAC_-_22_March_1949.pdf

Granted you may have to thrash the P-51H harder to get the performance and I doubt _anybody_ outside of Reno is going to run a modern P-51H (if one is flying) at anywhere near 90in MAP. 

Perhaps the Bearcat rolled better? 
The Bearcat has about 3% more wing area. (thats gross, net wing area may be different). weights clean are within a few hundred pounds of each other, Mustang may be lighter, it _may_ depend on WHICH F8F but I don't know. 
Turn is not 100% dependent on wing loading but it seems the two are very close. 

I doubt the "H" could out climb the Bearcat except in rare circumstances but the "H" is a much closer performer to the Bearcat (-1 model) than the "D".


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## davparlr (Jun 17, 2013)

Shortround6 said:


> I doubt _anybody_ outside of Reno is going to run a modern P-51H (if one is flying) at anywhere near 90in MAP.



I am sure you are correct.



> http://www.wwiiaircraftperformance.org/mustang/F-51H_Mustang_SAC_-_22_March_1949.pdf
> 
> 
> I doubt the "H" could out climb the Bearcat except in rare circumstances but the "H" is a much closer performer to the Bearcat (-1 model) than the "D".



I don't think your doubt here is supported by the referenced sites in this thread. Below is the data taken form krieghund post #6 for the F8F-1 and your reference above for the P-51H. Reference weight for the F8F-1 is 9360 lbs and is 9430 lbs for the P-51H. First number is rate of climb in ft/min for the F8F-1 and second number is the value for the P-51H

SL 4780 *5000*

5k 4000 *5000*

10k 3300 *4250*

15k 3280 *3850*

20k 2600 *3600*

25k 1950 *2800*

30k 1250 *2000*

Since there will probably never be a fly-off of these two planes all we have is opinion and some data. The data here seems to show the P-51H rather easily outclimbs the F8F-1.


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## davparlr (Jun 17, 2013)

GregP said:


> Come out and see us again sometime, Dave.



I had a great time! You bet I'll be back. I think I owe you guys a lunch.


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## GregP (Jun 17, 2013)

In the experience of the active wearbirds pilots I know, including some hall of fame pilots, no stock Mustang ever outclimbed a Bearcat if both were running correctly and were actually trying.

The Reno guys aren't about climb anyway, they are about speed, but Rare Bear DID set a world time to climb record that still stands. A stock P-51H doesn't exist anymore AFAIK, but the remaining ones still won't out climb a stock Bearcat. The only two Mustangs I am aware of that might are Voodoo and Strega, and both churn out more than 3,700 HP from engines that aren't really Merlins anymore.

If they use Nitrous Oxide in Rare Bear (not since Rod Lweis has owned it), it will produce about 4,500 HP. Without Nitrous it makes about 4,000 HP and is pretty much untouchable unless you have a 3rd or higher generation jet fighter designed for climb rate. But a stock Mustang? Nahhh ....


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## wuzak (Jun 17, 2013)

GregP said:


> In the experience of the active wearbirds pilots I know, including some hall of fame pilots, no stock Mustang ever outclimbed a Bearcat if both were running correctly and were actually trying.
> 
> The Reno guys aren't about climb anyway, they are about speed, but Rare Bear DID set a world time to climb record that still stands. A stock P-51H doesn't exist anymore AFAIK, but the remaining ones still won't out climb a stock Bearcat. The only two Mustangs I am aware of that might are Voodoo and Strega, and both churn out more than 3,700 HP from engines that aren't really Merlins anymore.
> 
> If they use Nitrous Oxide in Rare Bear (not since Rod Lweis has owned it), it will produce about 4,500 HP. Without Nitrous it makes about 4,000 HP and is pretty much untouchable unless you have a 3rd or higher generation jet fighter designed for climb rate. But a stock Mustang? Nahhh ....



Isn't the comparison supposed to be between a stock P-51H and a stock F8F-1?

FWIW, I believe the Spitfire XIV/21 or Spiteful XIV could beat the P-51H to 20,000ft, even if their initial climb rates were lower.


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## GregP (Jun 17, 2013)

Hi Wuzak,

I believe I said STOCK Bearcat and Mustang when talking about comparisons.

I said the Reno racers had more HP and better performance, but stock versus stock, the Bearcat was ALL OVER any Mustang in roll, climb, and turn. Pretty darned close in speed.


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## Jabberwocky (Jun 18, 2013)

Just for gits and shiggles, Hornet F.1 w Merlin 130/131 at + 20 lbs boost (1960 hp at 4000 ft/1840 hp at 17,000 ft) and 15600 lbs weight, July 1946 tests from http://www.spitfireperformance.com/spit14climbchart.jpg

0 ft: 5425 ft.min (~300 ft.min better than P-51H)
5,000 ft: 5425 ft.min (~950 ft.min better)
10,000 ft: 4,700 ft.min (1100 ft.min better) - 10,000 ft in less than 2 minutes
15,000 ft: 4,700 ft.min (1150 ft.min better) 
20,000 ft: 4,400 ft.min (1300 ft.min better) - 20,000 ft 
25,000 ft: 3,500 ft.min (1150 ft.min better) 
30,000 ft: 2,500 ft.min (800 ft.min better)

In addition, the Merlin 130/131 was cleared for +25 lbs boost with 150 grade fuel, giving 2,070 hp, so that's not even the best RoC that a Hornet could pull. 8)


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## fastmongrel (Jun 18, 2013)

Is climb rate a simple power versus weight equation or do other factors come into it.


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## Shortround6 (Jun 18, 2013)

A few factors but the main thing is figuring out how much power you have AFTER subtracting the power needed to _fly level_ at the _minimum drag speed_ or climbing speed. For a P-51H with bomb and rocket racks this seems to be 175mph at sea level. What ever power is needed to maintain level flight at this speed ( and this provides the lift to keep the plane in the air) is subtracted from the total power and remaining power is the power available for climb. 
Of course the power needed for the Mustang to fly at 175mph has to include the power needed to overcome the drag of the fully open (or mostly open) radiator door,, just like other planes when climbing have cowl and oil cooler doors/flaps open more max cooling so the drag is higher than the drag if the plane was simply cruising at 175mph.


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## Shortround6 (Jun 18, 2013)

GregP said:


> but stock versus stock, the Bearcat was ALL OVER any Mustang in roll, climb, and turn. Pretty darned close in speed.



Which Bearcat?

The -1 or the -2?

the -2 was about 1000lbs heavier in max _clean_ condition but it's "E" series engine ( about 200lbs heavier) offered an extra 150 HP for take-off _dry_ and much better altitude performance. It also used hydraulic drive for the supercharger and no shifting of gears. Power with water injection ???

part of the difference in engine power (supercharger) can be seen by the max speed of the -1 being 421mph at 19,700ft and the -2 going 447mph at 28,000ft. 

The Bearcats ( either of them) would be all over the P-51D but the "H" cuts into the margin quite a bit. 

Of course the difference in the P-51H performance rather depends on if it was using 67in, 75 in, 80 in or 90 in of MAP.


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## davparlr (Jun 18, 2013)

fastmongrel said:


> Is climb rate a simple power versus weight equation or do other factors come into it.



I am not an aero guy but I know enough to be dangerous so here goes. Power-to-weight ratio is certainly important, however other factors come into play such as airfoil design (airfoils have different lift-drag ratios,L/D, the higher the number the better). Another factor is aircraft cleanliness (aerodynamic efficiency). As already explained by Shortround6 above, climbing ability is not power-to-weight but rather excess power-to-weight (e.g., an aircraft flying at max airspeed cannot climb at that airspeed. It may have great power-to-weight but has no excess power to climb.) The less power required to maintain an airspeed, the more power available to climb. I believe this aids the P-51 in its climbing ability relative to its moderate power-to-weight ratio. The P-51H has a SL max speed of 413 mph, the F8F-1 can do 386 mph with a bit more power. This indicates the P-51H is a cleaner aircraft. If both were at SL (+100 ft ) and were flying side by side at 386 mph and had to climb, say for a hill, the F8F would have to lose airspeed in doing so, it is using all of its power to maintain airspeed. The P-51 could maintain 386 mph and climb, because it has excess power. So at SL and 386 mph, the P-51 could out climb the F8F. One could calculate the excess hp available to the P-51 at 386 mph by knowing the power required at 413 mph (about 2200 hp) and applying the drag formula. Since drag increases by the square of the airspeed this hp number would be greater than you would expect (and hp is a cube!!??!). Anyway, I don't want to do it.


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## davparlr (Jun 18, 2013)

An interesting little sidelight comes from my youth. I grew up a couple of miles from Sherman Field at Pensacola NAS. As such, I was expose to many wonderful air shows. One beautiful, (but hot) summer day I went to an airshow at the base. They had both a P-51D and an F8F scheduled to do demos sequentially, the P-51 was first. It took off, flew for a few minutes and landed early. The Navy announcer took pride in saying that the P-51 had over heated and that this was an example of the superiority of the air cooled F8F engine. Next the F8F took off, flew for a few minutes and landed early. Quietly, the announcer said that it had overheated.


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## fastmongrel (Jun 18, 2013)

Similar thing happened when I was at RNAS Yeovilton. There was a display by Firefly to be followed by a Corsair the commentator was telling us how reliable Corsairs were with round engines compared to the Fireflys V12 just as the Corsair blew its oil cooler and had to be towed off the runway by a Land Rover


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## GregP (Jun 18, 2013)

I love the Hornet / Sea Hornet. Aesthetically, for me, it is a winner and far better-looking than even the Mosquito. Many might dsiagree but there is no "right" or "wrong" for what is a good looking plane.

Rate of climb-wise, it is very good, but would never maneuver with a Bearcat. The wing loading for the Sea hornet F Mk.III is about 57.9 pounds per square foot at 20,893 pounds and the power loading is 5.0 pounds per HP. For the F8F-2, the wing loading is about 39.3 pounds per HP at 9,600 pounds and the power loading is about 4.36 pounds per HP. So the wing loading is about 32% better for the Bearcat and the power loading is about 13% better, with both of these at normal takeoff weight. No dount this might change slightly at best combat weight.

Advantage Bearcat in both wing and power loading, as far as that goes. It means that to me, while not necessarily so, I would not be surprised if the Bearcat climbed slightly better, turned quite a bit better, and accelerated better.

The span loading is 268 pounds per foot for the F8F-2 and 464 pounds per foot for the Sea Hornet F Mk. III, meaning the Bearcat would be expected to be considerably more maneuverable as altitude increases.

That said, I have always been a fan of the Hornet / Sea Hornet, and both were near the end of the piston era, so they would likely not have been employed as first-line fighter aircraft except in a limited war anyway. Both would no doubt give a good account of themselves versus most of the available piston opposition in such wars while being somewhat on the defensive versus the existing jets of the late 1940's and early 1950's. No doubt both would have been a diffcult kill for the jets, just as the jets would have been a difficult kill for the two pistons. If the jets had made the mistake of slowing down for a fight, either of the pistons would likely have eaten them alive.

In any case, they are two of the best of the last of the piston era in real life. Some "what if" planes crop up occasionally, but these were real, live, service aircraft. We HAVE some Bearcats flying and I wish we'd see a Sea Hornet (or two) restored and flying today. If nothing else, it was magnificent. I bet the sound was unforgettable. The only thing close today might be hearing a Lancaster fly over. I haven't but surely wan to hear that. I heard a Shackleton fly past once and it MUST be at least similar.


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## Jabberwocky (Jun 18, 2013)

GregP said:


> I love the Hornet / Sea Hornet. Aesthetically, for me, it is a winner and far better-looking than even the Mosquito. Many might dsiagree but there is no "right" or "wrong" for what is a good looking plane.
> 
> Rate of climb-wise, it is very good, but would never maneuver with a Bearcat. The wing loading for the Sea hornet F Mk.III is about 57.9 pounds per square foot at 20,893 pounds and the power loading is 5.0 pounds per HP. For the F8F-2, the wing loading is about 39.3 pounds per HP at 9,600 pounds and the power loading is about 4.36 pounds per HP. So the wing loading is about 32% better for the Bearcat and the power loading is about 13% better, with both of these at normal takeoff weight. No dount this might change slightly at best combat weight.



Sea Hornet Mk XX and Mk XXI standard loaded weight (no external stores) was 15,682 lbs, not 20,893 lbs. Hornet F.1 standard loaded weight was 15,600 lbs. Data from FAA and RAF testing and data sheets.

Wing loading is thus 43.5 lb per sq ft, ~ 10% worse than the Bearcat. Power loading with Merlin 130/131 at 1,960 hp is 4.04 lb per hp, or about 7.5% better than the Bearcat.


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## GregP (Jun 18, 2013)

C'mon Jabberwocky, the F.3 was the last Sea Hornet in regular RAF service and was the most produced. Somebody's leading you down the primrose path with the 15,682 pounds.

Empty was 12,502. 432 gallons of fuel add another 2,596 pounds. 760 shells adds 433 pounds plus the weight of the belt hardware. Call it 450 pounds. Call the pilot 200 pounds in flight gear with parachute. On the Gurmman there were about 150 pounds of oil and ADI. Call it twice that for the Sea Hornet due to two engines; 300 pounds. That alone adds up to 16,048 and I'm sure we forgot things like survival gear and a few other items.

At less than 16,000 pounds you're not adding full tanks, ammo, pilot, oil, and ADI. Sorry, it doesn't wash. And if you really want to get down to brass tacks, the R-2800-30W was 2,250 HP at Military, but 2,500 HP at Combat WER.

Sould you fight a Sea Hornet at 15,00 pounds? Yeas, with a lot of ful gone. You can do the same ina Bearcat and fight it at half fuel and you're down to 9,030 pounds. But I calculate at takeoff with full fuel, oil, ADI, 200 pound pilot, and normal incidentals. It makes comparisons easier since you're not fighting about where in the mission the fight took place. The absouilte best time for perfoamance is right before the thing runs out of fuel and ammunition ... but if you fight there, you usually don't make it home.

The Sea Hornet comes very close to the Bearcat, with the wing loading for the Sea Hornet still 12.65% higher and the power loading very close, but still 3% worse. The span loading at this weight is still 31+% worse.

I don't want to fight about it at all, but I won't buy a Sea Horent being better except in range, and can't find a reoported rate of climb that is anywhere near an F8F-2 at Combat WER power. The best I can find is about 4,560 fpm. An F8F-2 at WER will exceed 6,000 fpm. If not, how DID they set that 1946 record of zero to 10,000 feet in 94 seconds with a stock Navy aircraft?

Good thing they were on the same side, but they were both relatively short-lived. Wish we had a few Sea Hornets flying, as I said earlier. Since someone built a Mosquito, maybe we'll see a Sea Hornet sometine in the future. Both great planes that didn't quite make WWII.


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## Jabberwocky (Jun 18, 2013)

Not my figures Greg, they're the RAFs and the FAA's. Argue with them, not me.

Sea Hornet Mk XX and Mk XXI weights (http://www.wwiiaircraftperformance.org/mosquito/sea-hornet.pdf)

Tare weight: 11,700 lbs
Gross weight: 15,682 lbs (permanent tanks full)
Mean weight: 14,362 lbs
Light weight: 12,570 lbs

Hornet F.1 weight (http://www.spitfireperformance.com/spit14speedchart.jpg)

All up weight (A.U.W): 15,600 lbs

I'll dig up the RAF Pilots notes as well


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## wuzak (Jun 18, 2013)

GregP said:


> An F8F-2 at WER will exceed 6,000 fpm. If not, how DID they set that 1946 record of zero to 10,000 feet in 94 seconds with a stock Navy aircraft?



It was, apparently, an F8F-1.

It was modified so that WEP could be used with the landing gear down (interlocks preventing this otherwise).

And it took off into a 40kt headwind.

Per Rich Leonard.


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## Shortround6 (Jun 18, 2013)

It also used 1/2 fuel I believe and I think (but could be wrong) one plane had ammo but the other didn't?


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## GregP (Jun 19, 2013)

Sorry, don't buy it for an F.3. I havent researched an F.1 and probably won't, but the HP will certainly drop into the 1,770 or so range down from 2,030. The "light weight" above doesn't even allow for fuel weight, much less ammunition, pilot, oil, ADI, etc. Seems to be a plane with minimum fuel and no ammo. Sorry, don't believe it since it doesn't add up. I don't do comparisons at meaningless airshow weights, I do them at takeoff weight with full fuel and ammo for service planes and the Hornet is very good but not quite a Bearcat.

I find good references for the Hornet / Sea Hornet to be few and far between and have been in here long enough to have read Rich's account. I believe they were clean, no racks, and did the switch mod, too ... though that could be quite dangerous since you'd probably run out of rudder on takeoff if you stayed in the power. Probably had to reduce pwoer until the airspeed caught up with the rudder authority.

The Bearcat world records speak for themselves without my words, including the current and former world piston speed record plus the current and former world piston time to climb record. Seeing one perform in person makes one a believer. I'm not talking about an airsow takeoff at 1,700 - 1,800 HP, I'm talking about a max effort from a private strip. Never have seen anything do better ... but also haven't seen a Sea Hornet fly. The specs are enough to discount any rate of climb parity. I've never seen specs for the Sea Hornet that approach a Bearcat WER climb rate for a clean aircraft.

Please, no pissing contest. If you think otherwise, that's fine. I hope they make one and prove you right. At least then I could see and hear it fly. Maybe it could even set a world record.


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## Jabberwocky (Jun 19, 2013)

To add further to the Hornet weight question. 

The 1949 pilots notes for the F Mk XX gives a typical service condition weight of 16,100 lb. The 1950 pilots notes for the NF Mk XXI gives the all up weight of the aircraft in a typical service condition of "approximately 17,000 lb., i.e. with full internal fuel and ammunition". Given that the NF 21 was a two seater, with a radar in the nose, I'm not surprised there was weight creep. 

The weight penalty for navalizing the Hornet, including the naval equipment and radio, is given as 550 lb. 280 lb of that was for the folding wing.


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## GregP (Jun 19, 2013)

A pretty good plane regardless. I'd LOVE to fly one and still wish someone would complete one for flight. If they DO, it will likey be unarned and might be quite light.


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## wuzak (Jun 19, 2013)

GregP said:


> Sorry, don't buy it for an F.3. I havent researched an F.1 and probably won't, but the HP will certainly drop into the 1,770 or so range down from 2,030.



Why?

The F.1 and F.3 used the same spec engines - ie 130 series Merlins.




GregP said:


> The "light weight" above doesn't even allow for fuel weight, much less ammunition, pilot, oil, ADI, etc.



Don't think Hornets used ADI. Thought that is a minor weight in the scheme of things.

In this chart the F.1 is listed as 16,145lb AUW.
http://www.spitfireperformance.com/spitfire14-afds-speedchart.jpg


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## wuzak (Jun 19, 2013)

GregP said:


> I believe they were clean, no racks, and did the switch mod, too ... though that could be quite dangerous since you'd probably run out of rudder on takeoff if you stayed in the power. Probably had to reduce pwoer until the airspeed caught up with the rudder authority.



That probably wouldn't be a problem with Hornets since they had counter-rotating props.


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## GregP (Jun 19, 2013)

It was either ADI or WER boost. I'm leaning toward simple higher boost. They were 1,770 HP normal and 2,030 WER for a few minutes, however they got the "Emergency" rating.

Empty weight is not the same as basic weight. Basic weight is the weight that includes all fixed operating equipment, fixed furnishings, trapped fuel and oil, and water or other coolant in the radiator (if any), to which it is only necessary to add the variable or expendable load items, such as bombs, parachutes, and fuel for various missions. If basic weight typically adds about 1,000 pounds to a single engine Naval fighter aircraft, how much do you think it adds to a twin?

I might buy slightly under 16,000 for a Hornet, but not a Sea Hornet with arrester gear and Naval strangthening for carrier landings.

Figure the basic weight plus full internal fuel (432 Imperial gallons is 3,118 pounds, internal fuel [518.8 US gallons]), full armament (for the cannons only, I figure 450 pounds counting the cartridge band links), a pilot in a parachute and normal gear (200 pounds with parachute and charts, gun, water, food, etc. ... normal survival gear carried), radios and any other electronics that are not included in empty weight, and anything else required such as flares, etc.

Sure, you can FLY it under 16,000 pounds, but not at full capacity which was normal or even more for most combat missions. I do ALL calculations at full normal capacity, not max overload, since they flew that way or heavier almost all the time. You can calculate it anyway you like, but at least do it the same for both planes. Some people figure combat weight at basic plus pilot (in gear), plus 2/3 fuel, plus 2/3 ammo, plus radios and other gear. That's OK and even maybe desirable but the data aren't available for all planes, so I just use full internal capacity, without any external fuel to level the playing field. 

If a bomber, I include a "typical" bomb load for the mission length, as gotten from references. For instance, the B-17 could lift a LOT of weight but, for London to Berlin and back, it "typically" carried 4,000 pounds. Sure there were 6,000 and 8,000 pound (maybe heavier) loads for shorter missions, but they weren't the norm.

So, under 16,000 pounds for a Sea Hornet? I think not if you use full internal capacity as I did for the Bearcat. It, too, gets lighter as the mission proceeds. For an airshow? Sure, you might fly the Hornet with no ammunition, 1/3 fuel, no survival gear or rations, flares, etc. and put dimunitive Eric Brown in it for a lightweight pilot to boot. You can do that with a Bearcat, too, but nobody did in combat service use. They loaded for a survivable mission, not a show. I bet they never launched at under 16,000 pounds for a real mission, especially if it happened to be a real combat mission, and they flew some of those. Probably had drop tanks and underwing bombs or rockets to boot. Mostly, I'd bet they launched at 18,000 - 19,500 pounds and came back to base at 15,500 pounds when they recovered.

The Bearcat usuaully launched at 10,000 - 12,500 pounds and probably recovered at 8,400 pounds or so.


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## Hop (Jun 19, 2013)

> An F8F-2 at WER will exceed 6,000 fpm. If not, how DID they set that 1946 record of zero to 10,000 feet in 94 seconds with a stock Navy aircraft?



I worked out the physics before and I'm pretty sure the only way a Bearcat could reach 10,000 ft in 94 seconds is at reduced weight (probably very little fuel and no ammo).


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## fastmongrel (Jun 19, 2013)

Nice site about the Hornet

The de Havilland "Hornet" "Sea Hornet"


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## krieghund (Jun 19, 2013)

Here is some more info on the Sea Hornet and Hornet Mk1


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## Mike Williams (Jun 19, 2013)

Neil Stirling previously posted some nice performance comparison charts on this forum that are interesting: http://www.ww2aircraft.net/forum/av...ation-allied-fighters-35640-2.html#post977793


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## Neil Stirling (Jun 19, 2013)

This from the the book The Grumman F8F Bearcat by Christopher Chant.

F8F-1 

9,386lbs normal loaded.
12,957lbs maximum loaded.

Engine: R-2800-34W

Combat Power 2,750hp (70" hg ?) 2,750hp sl.
2,450hp 9,600ft. ( I would expect fth to be about 12,900ft)
1,850hp 15,500ft.


Max speed at sl 421mph.
Max speed at 18,800ft 428mph.

Initial climb 5,610ft/min.

Time to 20,000ft 4 mins 54 secs.

He doesn't give a source for this information, but it looks reasonable given 2,750hp.

Looks like a low altitude monster!!!



Neil.


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## GregP (Jun 19, 2013)

Thanks Fastmongrel, Krieghund, and Mike! Appreciate it.

I see Neil used 58" for the Bearcat and estimated Hornet performance at 25 lbs boost (80" Hg). Considering they regularly ran the R-2800 on test benches at 150 inches (59 lbs boost), maybe 58" is a bit conservative. 58" was military power and 70" was WER. If you're going to use full boost (the 5 minute rating) on the Merlin 130 / 131, it makes sense to use full boost on the oither planes, too ... or restrict the Merlins to "Normal power."

That's why I tend to discount reports where one plane is being operated at the limit while an ostensible competitor is being restricted to less than full power. I've seen it happen from all sides. Anyway, there are several aircraft with very good climb, maneuverability, and acceleration. The Bearcat and the Hornet / Sea Hornet are certainly two of them.


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## Neil Stirling (Jun 19, 2013)

GregP said:


> Thanks Fastmongrel, Krieghund, and Mike! Appreciate it.
> 
> I see Neil used 58" for the Bearcat and estimated Hornet performance at 25 lbs boost (80" Hg). Considering they regularly ran the R-2800 on test benches at 150 inches (59 lbs boost), maybe 58" is a bit conservative. 58" was military power and 70" was WER. If you're going to use full boost (the 5 minute rating) on the Merlin 130 / 131, it makes sense to use full boost on the oither planes, too ... or restrict the Merlins to "Normal power."
> 
> That's why I tend to discount reports where one plane is being operated at the limit while an ostensible competitor is being restricted to less than full power. I've seen it happen from all sides. Anyway, there are several aircraft with very good climb, maneuverability, and acceleration. The Bearcat and the Hornet / Sea Hornet are certainly two of them.



Greg if you can provide Bearcat figures using 70"hg please do, or put together a spread sheet chart showing your estimations.

Although the charts are headed 1946 fighters all the aircraft had flown by April 1945.
The F8F-1 was cleared (When?) for 70"hg, however, I cant find reliable performance figures and I am not confident estimating it.
During 1946 or 47 the -4 Corsair (Some not many) was fitted with the 42W engine and this produced around 2,780hp.
The Hornets performance is estimated from performance at +20lbs boost.
All aircraft clean no racks.
Fire Power from Flying Guns World War II by G.Williams and E. Gustin

Bearcat F8F-1 58"hg = 2,400hp Combat, Military 2,100hp http://www.ww2aircraft.net/forum/aviation/f8f-bearcat-rate-climb-37299.html

Neil.


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## GregP (Jun 19, 2013)

Hi Neil, 

I've been trying to catch Steve Hinton for 2 - 3 weeks now on Saturday when he is there to ask to see his dash one pilot manual for the F8F, but he's been swamped with tasks. He did say the dash one may not tell the max climb since it is mostly operations. Has great charts for takeoff and typical mission profiles, but may not address WER climb (I asked him as he was leaving to test fly a freshly-restored Tigercat).

Hopefully the dash one DOES address WER climb and I can catch him soon.

You hit the nail on the head ... there is precious little charted data available that is reliable. Sometimes all you have is one number (mostly without altitude or speed) and we all know the speed and climb rate changes with altitude. I've seen a so-called pilot's manual in pdf format, and it gives performance that seems quite low compared with what we see today. Then you read the small print and it says the data were all compiled with full fuel ,full ammo, one 150-gallon centerline drop tank, and bomb racks installed. Removing the tank added something like 13 mph and removing the racks added another 10 mph ... but they never mentioned the effect on climb, and the climb data was a single number. I did notice the climb data were all with tanks and rack and made at Normal Power (2,250 HP) but the engine is actually rated at a WER of 2,500 HP. Also, they didn't give the altitude where the climb rate was measured. Frustrating, to say the least. For instance, I have some data for most of the top Japanese types by altitude, so I can create speed and ROC charts. But the weight and power settings are not specified with the data ... so how good is it? If I did it and posted it, I'd just take flak for it and I simply don't have the other information.

Back to the F8F, I would think that 3,750 fpm climb when carrying full internal fuel, full armament, plus a 150-gallon centerline tanks and bomb racks at 58" MAP would turn into a much better climb rate when clean with partial fuel and using WER of 70" MAP. I know what I have heard from Bearcat pilots, but talk is cheap.

So, I'm trying to find something that is believable as a reference rather than personal experience (I catch a lot of flak in here for relating pilot experience) though I believe Steve as he doesn't inflate things ... he flies a LOT of different warbirds and has no axe to grind. In fact, he sometimes flies things he doesn't like to fly just for the people to see (doesn't think much of a few warbirds that shall remain nameless). Anyway, I'll keep checking and get back to the thread.

By way of example, he was quoted in a magazine as saying the F model P-38 was faster than the J model. I asked him about it one Saturday and he said that while he was quoted correctly, they didn't suppply the context. In reality, the F model is a bit cleaner and is faster at equivalent power and rpm. But the J model has more powerful engines and is a faster aircraft at full power. All he intended to say was that the F was faster when crusing with a J and if both were at the same manifold presure and rpm. Alternately, to fly formation, the J model uses slightly more power than an F model.

I have no dog in this hunt since I like all the great piston fighters ... as well as quite a few jets.

As a matter of curiosity only, I've seen numerous references on the web for the Hornet / Sea Hornet showing 4,000 fpm as the rate of climb, one showing 4,650 fpm, and now the reference from you at over 5,000 fpm. I wonder if the loadout is known for your chart? I'd believe the high climb rate at very light weight (say, 1/3 fuel, no ammo, no survivial gear, pilot and chute in shorts), but not at full capacity ... that is, full internal fuel, full ammunition, full consumables, survival gear, and pilot with gun and parachute and maybe winter clothes.

Much the same can be said for the F8F. You CAN load it down and still get good performance, but you can also lighten it up and get sparkling performance. So, the numbers are pretty useless without other information to go along with them ... for ANY aircraft and many times the other numbers and conditions aren't noted on the charts or in the manuals.

Anyway, nice charts, Neil. Did you use Excel? Maybe add some gridlines?


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## Neil Stirling (Jun 19, 2013)

Hi Greg 

The -1 manual is available online, do a Google search you will find it, it is dated 1949 and lists 70"hg with 115/145 octane fuel. The charts Krieghund posted come from June 1945 and I believe represent the use of 100/130 octane. 

To say nothing would give me more pleasure would be a exaggeration, however, a document with the date stating the clearance of 70"hg would be a start. As the charts I posted very clearly state 1946 fighters. If this information is forth coming I can re do the Excel chart with grid lines and the P-47M.

BTW I rate the F8F-1 as top dog piston fighter at low altitude when using 70"hg.

Reference the Hornet and 4,000ft/min, it comes from "Flight magazine 45/46" climb to 20,000ft at an average of more than 4,000ft/min (+20lbs boost) 

Neil.


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## RCAFson (Jun 19, 2013)

DCG2U said:


> An unmodified production F8F-1 set a 1946 time-to-climb record (after a run of 115 ft/35 m) of 10,000 ft (3,048 m) in 94 seconds (6,383 fpm). The Bearcat held this record for 10 years until it was broken by a modern jet fighter (which still could not match the Bearcat's short takeoff distance).



I really doubt that this record stood for ten years unless it simply wasn't officially challenged. There were lots of jet fighters appearing in the late 1940s and early 1950s that could do considerably better.


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## GregP (Jun 19, 2013)

Yet it did stand for 10 years. That suggests the military wasn't interested in bettering it, but a record is a record.

Just for info, the guys that used to race Strega wanted to try for a new piston engine, propeller-driven world speed record, but the attemnpt would cost more than a race at Reno, so they shelved it. The plane will easily do 540+ mph but the cost is a major factor. They could probably also set a world time to climb record, but that, too, is very expensive. It isn't the setting of the record ... it is paying for all the equipment, the FIA representatives, and other people to be there when you do it to verify the numbers.


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## CORSNING (Jun 19, 2013)

Before I even get started, I'd like to say that I am only interested in the facts. From every thing I have read to date, the facts point to the Bearcat as being the premier climber. However, I have studied both graphs issued by the Bureau of Aeronautics, Navy Dept. and they go like this:

Both A/C clean (no pylons/shackles) and in all up combat condition. Altitude in meters, speed in mph and climb in fpm.

ALTITUDE...F8F-1........F4U-4
S.L...........394/4600...383/4770
.1,000.......415/4220...397/4780
.2,000.......419.3705...411/4800
.3,000.......415/3290...424/4810
.4,000.......410/3275...439/4290
.5,000.......424/3115...445/4340
.6,000.......434/2615...458/3880
.7,000.......434/2220...463/3300
.8,000.......431/1735...446/2650
.9,000.......425/1325...442/2125

Weight......9,334 lbs....12,480 lbs.
W.E.P.......2,400 hp.....2,450 hp.
Power load: 3.889+.....4.49 lbs./hp.
Wing load: 38.25+.....39.51 lbs./sq.ft.

I know the power load figures only apply when the engine is at its maximum output, but looking at both their weights vs. horse power the Bearcat should be dominant.???

Need help on this one guys, Jeff.


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## wuzak (Jun 19, 2013)

Are the altitudes correct? Seems low for max speed for each aircraft - 6-7000ft.

And low for the climb numbers.

I would expect that the F4U-4 would have superior climb as they get to higher altitudes because of the two stage supercharging (F8F-1 is only single stage). The F4U-4's engine would maintain power better, and at 10 or 20,000ft should hold a substantial power advantage.


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## Shortround6 (Jun 19, 2013)

Altitude is in meters, not feet.


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## wuzak (Jun 19, 2013)

Shortround6 said:


> Altitude is in meters, not feet.



It pays to read things thoroughly! Thanks - that makes more sense.


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## Shortround6 (Jun 19, 2013)

CORSNING said:


> I know the power load figures only apply when the engine is at its maximum output, but looking at both their weights vs. horse power the Bearcat should be dominant.???
> 
> Need help on this one guys, Jeff.




The Bearcat would be dominant at low level.
The Corsair would have 1800hp Military (not WER) at 23,000ft though. 
The Bearcat -1 had 1700hp Military at 16,000ft. It should have between 1400 and 1470hp at 23,000ft? 

Knocking off about 280lbs per plane for fuel burned in climb ( quite possible too low) you get a power to weight for the Corsair of 6.7lbs per hp and the Bearcat has 6.2lbs per HP. 
The Corsair has the possibility of WEP at that altitude, an extra 200hp or so?
The Bearcat-1 has little (50-75hp?) or no possibility of WEP at 23,000ft. manifold pressure has been dropping since 17,000ft ( OK since 18-19,000ft due to RAM but we are not giving credit for RAM to the Corsair either)there is no spare supercharger capacity or little gain to be had from the water injection. 

The engine in the -2 Bearcat is a different story.


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## Shortround6 (Jun 19, 2013)

wuzak said:


> It pays to read things thoroughly! Thanks - that makes more sense.



Read more than one thing wrong myself, no worries.


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## GregP (Jun 20, 2013)

Let's say we disagree and leave it at that. 

I, too, read things wrong once in awhile and sympathize. Maybe I did this one, maybe not, but nothing wrong with a late model Corsair of almost any variety. Becasue one plane is better doensn't mean all other are worthless. Even a football team not as good on paper wins sometimes. A good plane with a great pilot will win almost every time.


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## krieghund (Jun 20, 2013)

GregP said:


> Most Bearcat owners don't do a WER takeoff and climbout very often.
> 
> Naturally, I'll continue to look for the F8F-2 -1 pilot's manual for a reference other than a current pilot.



Greg I posted the FM here since 2007: http://www.ww2aircraft.net/forum/other-mechanical-systems-tech/f8f-bearcat-8251.html#post252299

Here is the engine portions of the manual


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## GregP (Jun 20, 2013)

Seems like it is just what Steve Hinton said ... the dash one doesn't cover a WER climb from ground level.

I'll still look for his manual since most of the pdf manuals I see online are NOT what the real manual says when I read one. Might be the same, might not be ... we'll see.


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## Neil Stirling (Jun 20, 2013)

CORSNING said:


> Before I even get started, I'd like to say that I am only interested in the facts. From every thing I have read to date, the facts point to the Bearcat as being the premier climber. However, I have studied both graphs issued by the Bureau of Aeronautics, Navy Dept. and they go like this:
> 
> Both A/C clean (no pylons/shackles) and in all up combat condition. Altitude in meters, speed in mph and climb in fpm.
> 
> ...



There were 2 types of engine fitted to the F4U-4, the -18W 2,400hp or the 42W 2,750hp, the 42W being fitted to some F4U-4B's from Bu No. 97486 onwards constructed after the 16th of August 1946. 

This chart with the 18W http://www.alternatewars.com/SAC/F4U-4_Corsair_ACP_-_1_March_1946.pdf dated 1 March 1946 shows much lower climb performance. This chart http://www.wwiiaircraftperformance.org/f4u/f4u-4.pdf date absent also shows the 18W but does show the use of 115/145 octane fuel and I think matches your figures. Either the second chart represents a re-rating of the -18W after March 1946 or the engine represented was the 42W. 

F4U-4 Vought F4U-4 Pilot 's Handbook of flight operation instructions (1944) F4U Corsair Documents Manuals | Aircraft Manuals / Documents.

12,480/2450 = 5.09 lbs/hp

12,480/2750 = 4.54 lbs/hp

Revised F4U-4 performance as of 1st April 1945 within here http://www.ww2aircraft.net/forum/flight-test-data/f4u-performance-report-comparisons-36776.html

Neil.


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## CORSNING (Jun 20, 2013)

Neil,

Thank you for the information and documents.

Jeff


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## Neil Stirling (Jun 21, 2013)

Thanks Jeff,

In order to try and get to the bottom of this I have ordered the 1947 F4U-4 F4U-4B manual.

Neil.


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## swampyankee (Jun 25, 2013)

CORSNING said:


> there's no way it could climb 6000 ft in 90 seconds.


 Correct that DCG2U. Go on now.[/QUOTE]

It demonstrated, in a stunt, but nonetheless demonstrated standing start to 10,000 ft in 94 seconds, which is about 6,400 fpm. Toss out ten seconds for ground roll, and the rate of climb is about 7,100 fpm. Even if normal combat weight is 50% higher, which I doubt, this would result in a rate of climb of about about 4,500 fpm.

The manual numbers are, of course, definitive for the weights and conditions given.


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## spicmart (Jun 25, 2013)

Could one build a Fw 190D or Ta 152 using Jumo 213S / DB 603N to match the F8F-2 in performance (overall and/or climb rate)?


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## GregP (Jun 25, 2013)

None of the Fw 190 variants were ever even close to the Bearcat in climb, yet all had very good engines.

The Ta-152 was never a factor but, since it did not even achieve 4,000 feet per minute, I think it would have required quite a horsepower shot to get there. I think you COULD have done so, but not with any of the existing engines. They probably would have needed something in the 2,850 hp range to do it.

Candidates might have been the DB 604, 607, or 610. The DB 604 was a prototype engine only and the DB 607 and 610 were more than 50% heavier than the Ta-152's real engine, so I sort of doubt that was ever going to be a real possibility. The DB 613 had the power, but was almost twice the weight of the Jumo 213. Again, not going to happen.

One possibility for climb improvement would have been for the Germans to go with a better propeller design with more blades, but that might all but eliminate the fuselage-mounted armament as effective guns. They stuck with the 3-blade prop in order to have an effective firing rate for nose guns.

It seems to me that the aircraft would have to be substantially modified to add another 50% to the climb rate, and they only delivered about 43 of them in the real war. A protracted development chasing climb rate might have resulted in none ever flying. Of colurse, they might also have gotten it done, had it been a priority. You can't argue thath the Germans weren't creative ... they WERE. I seriously doubt they'd ever chase a Bearcat's climb rate anyway since none were deployed to Europe in WWII or were even considered for such ... the war in Europe was over before the Bearcat was delivered to the fleet.


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## papashteve (Jul 18, 2014)

Hate to "necro" this thread but I have some info that could very much explain the F8F world record climb rate. I am going to copy/paste what I wrote in another thread I started on this forum (it was not getting much attention and this info is much more relevant here):

I recently received the official USN "SAC" for the F8F-1 Bearcat from the National Naval Aviation Museum and to my knowledge this document has never been made public on the internet. The performance figures are very high, much higher then any other previous figures I have seen for this aircraft. Here are some figures:

The performance listed is using 100/130 octane:

F8F-1: Weight (combat) - 9,672 pounds (bomb racks rocket launchers are assumed to be aboard)

Combat power (water injection):


BHP at SL - 2750 @ 2800 RPM

Rate of Climb SL: 5610 ft/minute

Time to climb: 20000 ft - 4.9 minutes

Max Speed at SL (combat power) - 366 Knots (677 kph)

Max Speed at alt (18800 ft.) - 372 Knots (688 kph).

Relevant pages/snippets from the document (highlighted):














Performance curves at combat loading and combat power are marked with the number (2). Military power curves marked with number (4). Normal power curves marked with number (5). 


The combat curves seem to be showing an RPM of 3000 at SL and then shifting to 2600 RPM - along with top speed decreasing right past SL rather then slowly increasing as altitude is gained until the second stage of the supercharger (rather odd, haven't seen this in other ww2 speed charts before?). This seems to contradict the power plant ratings on the first page posted above, not to mention the R-2800-34W shouldn't be running past its limit of 2800 RPM.

Am I reading the curves incorrectly? Can anyone explain the curves in detail?

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## davparlr (Jul 18, 2014)

papashteve said:


> Am I reading the curves incorrectly? Can anyone explain the curves in detail?



The speed curves seem way off for No. 2. 422 mph SL speed is unrealistic. In Spitfireperformance, the the F8F-2 charts, attached, show more accurate, I believe, data.

This is not the first data I've seen in this format I have had trouble with. The F4U-4 also seems off.

http://www.wwiiaircraftperformance.org/F8F/F8F-2_Standard_Aircraft_Characteristics.pdf


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## papashteve (Jul 18, 2014)

davparlr said:


> The speed curves seem way off for No. 2. 422 mph SL speed is unrealistic. In Spitfireperformance, the the F8F-2 charts, attached, show more accurate, I believe, data.
> 
> This is not the first data I've seen in this format I have had trouble with. The F4U-4 also seems off.
> 
> http://www.wwiiaircraftperformance.org/F8F/F8F-2_Standard_Aircraft_Characteristics.pdf



The data from the F4U-4 SAC is using 115/145 fuel as compared with the older SAC which uses 100/130 fuel. The performance figures with 115/145 fuel will be higher.

The F8F-2 and f8f-1 had different engines, the -2 was better suited for higher altitude with the R-2800-30Ws supercharger, while the -1s R-2800-34W was better sub 10k feet. 

Btw, the F8F-2 SAC is in the same format as the F4U-4s and the F8F-1's I posted here. I am told the F8F-1's SAC I posted here was the official one for the -1/1B


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## RCAFson (Jul 18, 2014)

Can you give the weights associated with each number on the graphs?

IIRC, the F8F-1 was not carrier rated.


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## papashteve (Jul 18, 2014)

RCAFson said:


> Can you give the weights associated with each number on the graphs?
> 
> IIRC, the F8F-1 was not carrier rated.



Curves (2)-combat power (4)-military power and (5)-normal power are all at 9672 pounds. 

What do you mean by not carrier rated? Unable to take off and land on carriers? If so that is very incorrect.


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## wuzak (Jul 18, 2014)

papashteve said:


> The performance listed is using 100/130 octane:
> 
> F8F-1: Weight (combat) - 9,672 pounds (bomb racks rocket launchers are assumed to be aboard)
> 
> ...



So, the climb to 20,000ft is about the same as for a Spitfire IX - the LF.IX with the Merlin 66 does that in around 4.75 minutes and the HF.IX with Merlin 70 in 4.85 minutes. These are with maximum boost of +18psi - which means it is with 100/130 fuel. A Spitfire IX with Merlin 61 and +15psi boost (ie an earlier model - around late 1942) could climb to 20,000ft in around 5.6 minutes.

The Spitfire XIV (actually an VIIIG) could do the climb in 5.1 minutes at combat rating.

I would suspect that the Bearcat gets a head start on the Spitfires until somewhere after about 10,000ft the Spitfires catch up or overtake the F8F.

Time to 10,000ft:
HF IX - 2.25 minutes
LF IX - 2.15 minutes
XIV - 2.3 minutes





papashteve said:


> ow here is what I find odd about the document. The combat curves seem to be showing an RPM of 3000 at SL and then shifting to 2600 RPM - along with top speed decreasing right past SL rather then slowly increasing as altitude is gained until the second stage of the supercharger (rather odd, haven't seen this in other ww2 speed charts before?). This seems to contradict the power plant ratings on the first page posted above, not to mention the R-2800-34W shouldn't be running past its limit of 2800 RPM.



There was no second stage for the F8F-1. It did have a two speed gearbox for the supercharger - hence the sawtooth shape of the graph.


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## Shortround6 (Jul 18, 2014)

Something seems to be off. There is an pilots manual for the Bearcat available on this site. 

http://www.ww2aircraft.net/forum/at...tech/43575d1181164775-f8f-bearcat-f8f-1-2.pdf

It has both charts and graphs for both engines. the -34W chart is on page 42 and gives a max MAP of 70 in between 6000ft and 10,000ft in *high* gear using 115/145 fuel. Somewhere between 4000ft and 6000ft the supercharger was shifted from low gear to high gear for war emergency power. For military power the supercharger appears to have shifted between 10 and 12 thousand feet. (and military power was at 49.5in in high gear and 58 in in low gear. 

The engine calibration curves are on page 76. The curves do not show war emergency power. 2300hp was available at sea level and a few hundred feet above using 58in MAP and 2800rpm. Power starts dropping before 1000ft is reached. no mention is made of water injection, however the engine was limited to 53.5 in MAP with 100/130 fuel for take-off with power hitting 2100hp at just over 3000ft. The engine using 115/145 would have dropped to the same power at that point. The limiting factor seems to be the supercharger. 

You can get much more than 58in of pressure by engaging the second gear of the supercharger at lower than "normal" altitudes. however there are no power charts or graphs for that except the already mentioned 70 in limit. 

I would note that the pilots manual gives much lower external loads than the above data sheet and the "max" bomb load listed can only be reached by leaving out about 1/3 of the fuel and oil.


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## papashteve (Jul 18, 2014)

Shortround6 said:


> Something seems to be off. There is an pilots manual for the Bearcat available on this site.
> 
> http://www.ww2aircraft.net/forum/at...tech/43575d1181164775-f8f-bearcat-f8f-1-2.pdf
> 
> ...



Like I said in the other thread, max bomb capabilities was 3600 pounds if you take the heaviest bombs you can carry - 1x 1600 bomb on the fusalage + 2x wing mounted 1000 pound bombs. That is correct. They did not fly the F8F-1's out like this though, they flew with 2x 1000 pounds on the wings and 1 fusalge 150 gal tank as a load out, for range. That load out is 12740 pounds which is the max take off weight listed in the document.

The F8F manual doesn't list the 1600 pound fuselage mounted bomb in its load outs for some reason. The F8F-1 1945 SAC (posted somewhere in this thread I belive) along with the one I posted here does however.


On the other hand, I managed to get a scan of the 1947 F8F manual's powerplant chart for the F8F-1 R-2800-34W (100/130). Sadly it says under combat power that "This information will be supplied at a later date". I guess that later date was the 1949 revision of the F8F manual, but they had moved onto 115/145 fuel so the 100/130 power settings are still somewhat of a mystery..


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## GregP (Jul 18, 2014)

At full internal fuel, however, with pilot, and ammo, it's a climbing fool with few equals anywhere. That's full ammo and full internal fuel.

Lighter would be useless since if you left out the ammunition, there's no reason to sortie the Bearcat. If you left out much internal fuel, you could sortie, but you wouldn't go very far ... maybe as far as a typical Spitfire.


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## wuzak (Jul 19, 2014)

GregP said:


> At full internal fuel, however, with pilot, and ammo, it's a climbing fool with few equals anywhere. That's full ammo and full internal fuel.
> 
> Lighter would be useless since if you left out the ammunition, there's no reason to sortie the Bearcat. If you left out much internal fuel, you could sortie, but you wouldn't go very far ... maybe as far as a typical Spitfire.



The Spitfire climb data is for full fuel and ammo (well, at least the weight equivalent to that).

The F8F carried 185 USG of fuel internally - that is 154 UKG.

The IX carried 85 USG in early versions, plus some were equipped with 36 gallons in the win and later versions (ie still pre-dating the F8F-1 in service) were fitted with 33 or 41 UKG rear fuselage tanks.

VIIIs had 124 UKG in the fuselage tank and leading edge tanks.

Early XIVs had 109.5 USG. in fuselage and wing leading edge tanks. F.XIVEs had an additional 33 UKG rear fuselage tank too, for a total of 142.5 UKG.

XVIIIs (improved XIV) had 175.5 UKG in fuselage wing leading edge and rear fuselage tanks.

Given that the R-2800 was thirstier than the Merlin I don't think an F8F without external tanks is going further than an VIII, and not much further than an early IX.

The R-2800 probably guzzles more fuel than the Griffon too, so the F8F's range won't be much more than an early Spitfire XIV's, and probably less than the XIVe, which had almost as much fuel. And won't go nearly as far as the Spitfire F.XVIII.

The idea behind the Bearcat was similar to the Spitfire - climb fast to engage the enemy. Endurance was not a prime consideration.


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## Neil Stirling (Jul 19, 2014)

Excellent!!! Papasteve!!! Looking for this for a long time. Would you please post the rest of the document.

Neil.

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## RCAFson (Jul 19, 2014)

papashteve said:


> Curves (2)-combat power (4)-military power and (5)-normal power are all at 9672 pounds.
> 
> What do you mean by not carrier rated? Unable to take off and land on carriers? If so that is very incorrect.



OK, I remember now. The F8F-1 had severe handling problems and it was grounded at least once due to fatal accidents but it was carrier rated. The -2 had numerous improvements including a modified tail.


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## papashteve (Jul 19, 2014)

Here is the full document:


Any thoughts on the combat curves?

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## Neil Stirling (Jul 19, 2014)

Thank you very much!!!!
O.K best guess.
Using Supercharger low gear.
Combat curve 4, Speed military power 54"hg , almost certainly without water injection.
Combat curve 2 WEP. Water injection 70"hg
Water injection on its own adds about 11kts to speed. The use of WEP drops the full throttle height from about 6,000ft to Sea Level, the height at which maximum speed is attained when using low gear. As the supercharger is now giving its best, speed falls off with altitude. When at about 12,000ft high gear is engaged and speed starts to increase, now at 15,000ft the curve speed decreases again? This could be due to high engine temperatures (Carb air intake?) or some other issue. Anyway shortly after that curve 4 bisects 2 and Military power is used. 
The Standard Aircraft Characteristic doc does not match the power plant chart contained within the F8F-1 pilots notes, however, the F8F-1 SAC doc does state that its based on flight tests and calculations. I think we are missing some other document that may well clear things up. 
For now I will go with the new information you have provided.

Thanks again.

Neil.

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## Shortround6 (Jul 19, 2014)

I could be wrong but what I _think_ is going on is that they are using high gear in the supercharger at sea level for the WEP. 

AS the plane climbs the the engine power (manifold pressure) falls off until at around 12,500ft the supercharger can't supply much more air than it can at military power. It is still getting the boost from the water injection even at the military power boost setting ( cooler charge is denser), but why the water injection stops at 15,000ft I have no idea. 

Please note that the speed and climb charts have different "notches" due to RAM. 

Now wither they really operated the planes this way for any length of time is another question, especially after the war when the _need_ for 366kts at sea level vs blown engines was a lot less.


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## wuzak (Jul 19, 2014)

SR, are you suggesting they start off in High gear, switch back to Low at ~12,500ft, at which point the aircraft starts to get faster until it reaches critical altitude in Low @ 15,000ft, starts slowing again and then switches back to High @ 17,500ft?


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## Shortround6 (Jul 19, 2014)

No, I think they start in high gear and leave it there. 

In the pilot's manual that has the instructions for both the -1 and -2, which probably means it is dated later than this set of documents, the R-2800-34 engine in WEP was in high gear at under 6,000ft with a max MAP of 70in and stayed in high gear all the way up. The MAP was supposed to be at 70in from 6,000 to 10,000ft and after that it was full throttle, ie, whatever boost the supercharger would supply. 

In low gear the engine won't even hold 58in at 2000ft for military power. The supercharger just won't give any more air at sea level or just above in low gear and water injection won't get you another 650hp. You need a _lot_ more boost and the only way to get it is to use the high supercharger gear. I would note that high gear _seems_ take or cost the engine 300hp for similar RPM/boost settings compared to low gear. Higher power to supercharger (about 68% more), more charge heating and at times pumping losses due to throttling. 

A Bearcat engine making 2750hp has to be developing several hundred _more_ Horsepower in the cylinders than an R-2800 in a late P-47 making 2800hp because the P-47 is using the exhaust gas to power the turbo to get it's 70-72in MAP rather than taking power from the crankshaft. Granted the "E" series engine in the Bearcat used a bit different supercharger on the engine itself. To get the same power at the crankshaft you need more boost than the P-47 engine. 

Maybe, I repeat *maybe*, by the time the manual was written compared to when this data sheet was _originally_ written, the Navy backed off a bit on the allowable boost at low altitude.


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## wuzak (Jul 20, 2014)

I would think that if the high gear was used the whole time it would not have the sawtooth at 12,500ft - it would just decrease in speed until it met the high gear curve.

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## tomo pauk (Jul 20, 2014)

Looks to me that WER in second S/C gear was not running on full RPM.


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## Shortround6 (Jul 20, 2014)

tomo pauk said:


> Looks to me that WER in second S/C gear was not running on full RPM.



Supercharger doesn't have a choice does it? if it is in high gear it is turning 9.45 times as fast the crankshaft. You can close the throttle plate to restrict the boost/power.


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## Neil Stirling (Jul 20, 2014)

The SAC document is from 1949 and states that the fuel used is 100/130. I don't think that this is a mistake. For whatever reason the USN decided that it could operate the Bearcat with this fuel and 70"hg. Things were fine in low gear but again for whatever reason problematical when using high gear, hence the odd shape of the curve. 

Neil.


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## papashteve (Jul 20, 2014)

Neil Stirling said:


> Thank you very much!!!!
> O.K best guess.
> Using Supercharger low gear.
> Combat curve 4, Speed military power 54"hg , almost certainly without water injection.
> ...



The missing document to explain this performance would most likely have been this one, it is from the 1947 F8F-1 manual (before the 1949 revision of the manual which used 115/145 octane). Note the use of 100/130 octane:

Sadly, combat power settings are not shown as it is written that it would be supplied at a later date. The later date was the 1949 revision of the manual, but they had moved on to 115/145 octane..


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## Shortround6 (Jul 20, 2014)

Neil Stirling said:


> The SAC document is from 1949 and states that the fuel used is 100/130. I don't think that this is a mistake. For whatever reason the USN decided that it could operate the Bearcat with this fuel and 70"hg. Things were fine in low gear but again for whatever reason problematical when using high gear, hence the odd shape of the curve.
> 
> Neil.



I am not so sure that things were "fine" in low gear. 

Things were "fine" in the sense that with both fuels military power didn't change with either gear. The problem is that the supercharger was already maxed out in low gear and simply would NOT supply any more air (or depended on RAM to do so) over a few thousand feet of altitude. Take-off power (dry) with 100/130 was limited to 53.5in (2100hp) and this could be held to just over 3000ft. Using 115/145 fuel allowed 58in for take-off (and another 200hp) but it could only hold this to 5-600ft and as the the altitude rose the pressure dropped to where, at a bit over 3000ft, the pressure was the same (53.5in) as using the lower grade fuel and by the time you reach 8000ft the pressure was down to 46in and power is down to about 1800hp. Water injection can help some but the supercharger is just not going to flow anymore air using the low gear ratio. 

In high gear they _may_ have limited the Military power to 49.5in instead of the 53.5/58in used in low gear due to the extra heat in the intake charge generated by the higher compression taking place. OR trying to balance the actual load in the cylinders.


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## GregP (Jul 20, 2014)

Does anyone have any design documents on the supercharger used to suggest it was maxed out in flow at 2,800 rpm in low gear or is this guesswork?

To me it looks as if combat power produced significant extra power until somewhere around 17,000 feet at which time the Combat and Military curves join. Since both the Combat and Military ratings are at 2,800 rpm, the difference would have to be with water-methanol boost only. Otherwise, there will not be any change in manifold pressure since the engine is running at the same rpm for both power settings and hence the airflow is the same. That leaves only W-M injection as the difference maker in flow.


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## Shortround6 (Jul 20, 2014)

In the manual referred to earlier there are engine calibration charts on page 76. 

At 2800 rpm in low gear the engine gave 58" at sea level to 500-600ft, it was down to 46" at 8000ft, 32" at 16,000ft and 30" at about 19,500ft. Chart gets little sparse but you might be down to 22-24in at 26,000ft (last line on chart in low blower) where the engine would be making a bit under 900hp. High gear kicks the Pressure up to 33-34in at 26,000ft and power is about 1200hp or a bit under. 

The only "kink" in the lower gear, 2800 rpm pressure line is at just over 3000ft where the the engine has to be throttled to 53.5in if using 100/130 fuel to limit the engine to 53.5". 

It was quite common to limit the boost in WEP by part closing the throttle below the FTH for WEP. 

I doubt that water injection is going to boost the manifold pressure from 58" to 70" or 70+" just by cooling the charge while the supercharger impeller spins the same speed. 

This 1949 manual gives WEP settings of 70" in _HIGH_ gear from 6,000 to 10,000ft ( 3 lines on the chart ) from which we _may_ assume that in high gear the engine could pull 70in at 10,000ft had had to be throttled back at lower altitudes to keep from exceeding 70in. 

The engine calibration chart does NOT take RAM into account while the power plant charts given in the post and in the manual on page 41* do* so there _will_ be a discrepancy of several inchs of boost or several thousand feet.


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## GregP (Jul 20, 2014)

Thanks SHortround,

My observation / question would then become along these lines.

The Combat and Military power are both at 2800 rpm and full throttle.

Both would have the throttle full forward at 2,800 rpm, and I am assuming auto-rich mixture. So, same throttle setting, same rpm, same mixture. What is the difference between Combat and Military, other than the water-methanol injection?

I am not arguing, I am confused. In the Standard Aircraft Characteristic pages above, the difference in pwoer is significant, yet both at at the same RPM. Combat power (or WER) doesn't mean "change the supercharger to high gear." It usually means "push the throttle fully forward and break the wire guarding the Combat or WER setting." All that does is engage water-methaniol injection, as far as I know. What belse would it do to enhance the horsepower? OPuching the throttle forward doesn't change gears ...


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## wuzak (Jul 20, 2014)

In WER mode the throttle is opened wider at the same altitude, allowing higher boost to be reached by the supercharger. ADI is only used to prevent this from damaging the engine through detonation.

So, in the case of this R-2800 the throttle only becomes fully open at 6000ft in Military power, but is open fully from 0ft in WER power.

The throttle is used below critical altitude to prevent the engine from over-boosting.


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## GregP (Jul 20, 2014)

Makes sense, Wayne. Thanks.


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## Shortround6 (Jul 20, 2014)

A lot of engines had an automatic boost limiter on the engine,that would limit the maximum boost of the engine to a preset value by closing the throttle butterfly. Think of it as gating down/restricting the intake. Like Early Merlins being set to 6lbs boost. The supercharger could supply 6lbs/42in (or close) at 16,250ft and no more. Below that height it could supply 12lbs/54in at 9000ft and 16lbs/62in at 5500ft and so on. That is were the WEP power came from. _Extra_ supercharger capacity that was not being used at military power settings due to detonation limits of the fuel being used or concerns about engine life. If you change to a Merlin X with 6:89 low supercharger gears instead of the Merlin IIIs 8.588 gears and you "break the wire/punch the tit,etc" at low altitude your supercharger impeller is going to be turning about 80% as fast as the Merlin IIIS impeller which is going to seriously affect the max amount of boost you are going to get. Like 10lbs/50in at sea level? 

With the Merlin III there was NO WER/combat power available _above_ 16,250ft (except that supplied by RAM) because the supercharger was maxed out. 

Much like the Allisons being able to pull 70" or so at sea level (depending on supercharger gear) but only being able to give 44-46in at 12,000ft or so. At 12-13,000ft there was no WEP but a sea level???? hold on tight  

A lot of the American radials used two speed superchargers to increase take-off performance with low gear maxing out at 3-6,000ft which doesn't leave much room for extra supercharger capacity/ combat power in low gear. 

I don't know how the WEP control set up on the Bearcat worked but just injecting water/alcohol isn't going to do a whole lot to increase pressure. A post war commercial R-2800 engine was good for 2400hp for take-off at 2800rpm using 56in boost and ADI. 2100hp at 3000ft at 2800rpm dry which matches the Bearcat engine very well. So the water _appears_ to be good for about 100 extra hp while running 2" less boost on 100/130 than a -34W engine using 115/145. 

And that is the 'secret' of water injection and WEP. It allowed higher boost to be used (if available) while preventing detonation. 

The pilots manual doesn't have a real good section on emergency power for the -1 and the -34W engine but does say to use high gear at altitudes where power is not available in low blower and says to use high blower for combat power at altitudes as low as 6000ft in the power plant chart and while 70in listed until 10,000ft, F.T. (full throttle which _suggest_s but does not prove that 70in was less than full throttle at the lower altitudes) is listed at the higher altitudes. 
Again, I don't know how much juggling of throttles, boost controls, supercharger shift levers was needed. The -2 Bearcat went to a single lever control. Can't imagine why


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## GregP (Jul 20, 2014)

In the case of the last piston fighters, going to a single lever afforded easier operation at the expense of fine control.

US pilots praised the single-lever power control of the Fw 190's BMW 801 in mock combat, but said it made formation flying very difficult because fine control was lost. It also made cruising around very economically impossible because there wasn't a lot a fiddling you could do with only one lever.

In combat I like the single throttle lever. 

If you are NOT in combat ... which is 99+% of your flying time ... I'll take a throttle, mixture and prop lever anytime over a sinlge power lever for the extra options and control afforded. Of course, once wewent to jets, we had only one lever from then on forward per engine.


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## BiffF15 (Jul 20, 2014)

Greg,

I had heard the same thing about the Fw-190 single lever engine control. However, I always thought it was due to Tank looking at things through the eyes of a young pilot (how do I as the designer make it easier for the new guy) and as such downloaded that. Just reading all the numbers pilots had to remember for blower speed / altitude change over, constant adjusting of throttle, prop and mixture, etc. Also there was a point in which the average Luftwaffe fighter pilot wasn't doing much cruising since he was in fear of getting bounced at almost all times.

All the above is my opine only!

Cheers,
Biff


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## BiffF15 (Jul 20, 2014)

Gents,

Off thread so I apologize, but I'm trying to find out info on a fighter pilot named Thomas J Humphrey. Should be of Korean war vintage and possibly flew with Gabby G.

A google search didn't help much and am curious if there is a Korean War database for USAF pilots or something that could help. Any help would be appreciated!

Cheers,
Biff


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## GregP (Jul 21, 2014)

I went to an online search, but they want $25 or $70 (5 or less pages, more than 5 pages) and a lot of information to retrieve a service record.


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## BiffF15 (Jul 21, 2014)

Thanks Greg. One of the guys I work with bought some stuff at an estate sale and wanted it to go to his family (like a signed autobiography of G. Gabreski to this individual).

Cheers,
Biff


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## Neil Stirling (Jul 26, 2014)

Maybe this helps to explain why there is a mismatch between the SAC and pilots manual.

Neil.

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## grampi (Jul 29, 2014)

CORSNING said:


> I agree with Greg, unless the battle is more than 500 mls. from home......I'm just saying, That was the reason the Mustangs Allison/Merlin were so valuable.



....or if the battle were to take place above 20K feet...the Stang is a better performer at high altitudes...


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## BiffF15 (Jul 29, 2014)

Grampi,

I agree with your statement, however it's a little bit of apples to oranges comparison. The Mustang was a well designed fighter, very low drag. Add fuselage tanks and RR power and it went from good to great as it flew MUCH further than it's contemporaries and handled roughly the same as they did.

The Bearcat on the other hand was designed well after, was built to land on a carrier (tail hook, folding wings and their weight penalties) and designed to combat a different type of threat. Good low speed handling qualities a tremendous climb rate while fighting at lower altitude resulted in the Bearcat being what it is (and isn't) as compared to a Mustang. 

They are probably my two favorite US fighters of WW2!

Cheers,
Biff


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## grampi (Jul 30, 2014)

BiffF15 said:


> Grampi,
> 
> I agree with your statement, however it's a little bit of apples to oranges comparison. The Mustang was a well designed fighter, very low drag. Add fuselage tanks and RR power and it went from good to great as it flew MUCH further than it's contemporaries and handled roughly the same as they did.
> 
> ...



Maybe that's why most people say the P-51H is most comparable to the Bearcat...both were designed around the same time and had similar performance numbers...the P-51D was designed and built several years earlier, but was the most widely produced and popular model, so many times it ends up being compared to the Bearcat, when in reality, that's more like comparing the P-40 to the P-51...

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## Shortround6 (Jul 30, 2014)

You also have two different Bearcats, or at least two rather different engines.

The second engine being able to produce power at 22,000ft that the earlier engine made at 17-18,000ft.


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## CORSNING (Jul 31, 2014)

Agreed shortround. Kind of in the likeness of the Packard V-1650-3 vs V-1650-7 in the Mustang.

Jeff


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## grampi (Jul 31, 2014)

CORSNING said:


> Agreed shortround. Kind of in the likeness of the Packard V-1650-3 vs V-1650-7 in the Mustang.
> 
> Jeff



Or either of those vs the V-1650-9...


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## grampi (Jul 31, 2014)

I know this is a bit off topic, but in regard to the climb record currently held by Rare Bear, I do believe there is a plane that can beat that record, or least come very close to beating it...and that plane is a Thunder Mustang...I've been doing quite a bit of research on the TM and its pilots claim it will peg the VSI gauge (which only goes up to 6K ft/per min), so they don't really know how fast it climbs (they know it's doing AT LEAST 6K ft/per min). They said 180 knots is optimal climb speed, and to keep the speed down to 180 in a climb takes about a 45 degree climb angle...that's impressive! Sorry for the off topic post, just thought it was interesting...


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## GregP (Jul 31, 2014)

The Thunder Mustang is very impressive but it doesn't hold that initial rate for very long. It isn't all that fast relative to the Reno racers, but since it is a fiberglass unit. not built for wartime stress, it is relative light compared wuth the pwoer installed. What a neat plane!

Rare Bear is supercharged, runs ADI, and can run Nitrous Oxide if they want to do so ... and the Bear holds climb rate quite well, at LEAST to 10,000 feet or more. By the way, for those who don't know, Rare Bear set a world time to climb record for 3,000 meters (9,842.5 feet) in 91.9 seconds ... from a standing start. That was in 1972 when Rare Bear wan't making anywhere NEAR the horsepower it is now ... plus the plane has been sorted out quite nicely since 1972!

The Bear could beat it's own record significantly at this point in time, but there is no reason to spend the money to do so since it already owns the record and nobody else has gotten even close as yet ... at least nobody who has the ~$1M USD it takes to set the record.


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## grampi (Aug 1, 2014)

GregP said:


> The Thunder Mustang is very impressive but it doesn't hold that initial rate for very long.



How do you know this? I've been doing quite a bit of research on the TM and I have not seen anything that that suggest this...


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## Shortround6 (Aug 1, 2014)

One clue is the 24,000ft service ceiling. 

Another is getting 640hp from 601 cu in at 4800rpm. Anybody got any details on _IF_ the engine has a supercharger? 

Since the air at 10,000ft is 73.8% as dense as it is at sea level the engine will make 73.8% of the power _unless_ the supercharger set up is rigged to accommodate the pressure/density drop.


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## grampi (Aug 1, 2014)

Shortround6 said:


> One clue is the 24,000ft service ceiling.
> 
> Another is getting 640hp from 601 cu in at 4800rpm. Anybody got any details on _IF_ the engine has a supercharger?
> 
> Since the air at 10,000ft is 73.8% as dense as it is at sea level the engine will make 73.8% of the power _unless_ the supercharger set up is rigged to accommodate the pressure/density drop.



It doesn't come with a supercharger, but they have them available for the Falconer engine...


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## Shortround6 (Aug 1, 2014)

For comparison *stock* Bearcats had either a bit under 2100hp at sea level which _increased_ to 2100hp at a bit over 3000ft and then tapered off to a bit over 1650hp at 10,000ft on the early ones (78.5% sea level power) _without_ water injection, 115/145 fuel or shifting into high gear. The later ones (using 115/145) had 2200hp at take-off and still had 1975hp or so at 10,000ft. 

I don't know what Rare Bear was using for power when it set the record but _some_ R-3350 engines in Skyraiders ( source for Rare bears first engine?) were rated at 2700hp for take-off and 2700hp at 3700ft military power dry. 

Without some form of supercharger the Falcon engine is going to be down almost 8% in power at 3700ft. (590hp?) 

Rare Bear didn't have any guns, ammo, armor and had lighter fuel tanks than the military self sealing tanks and likely lighter radios/avionics. The Wright engine and new prop were heavier than stock though. 

A Military Bearcat clean but fully loaded weighs just about 3 times what a Thunder Mustang does yet has 3.28 times the power at sea level and may have 3.48 times the power at 10,000ft (early one) to 4.15 times the power at 10,000ft for a late one. 

With Rare Bear being both lighter and more powerful than a stock Bearcat a Thunder Mustang is going to need a *LOT* of power to take the record away.


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## GregP (Aug 4, 2014)

When I looked at a Thunder Mustang with the Falconer V-12 it didn't have a supercharger. Hence my statement that it won't sustain the climb rate for too long. We all know what happens to normally aspirated engines as they go up in altitude ....


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## grampi (Aug 5, 2014)

Yep, a Thunder Mustang would require a blower to be competitive in this event...I didn't take into consideration what altitude does to engine performance...


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## grampi (Aug 5, 2014)

Shortround6 said:


> For comparison *stock* Bearcats had either a bit under 2100hp at sea level which _increased_ to 2100hp at a bit over 3000ft and then tapered off to a bit over 1650hp at 10,000ft on the early ones (78.5% sea level power) _without_ water injection, 115/145 fuel or shifting into high gear. The later ones (using 115/145) had 2200hp at take-off and still had 1975hp or so at 10,000ft.
> 
> I don't know what Rare Bear was using for power when it set the record but _some_ R-3350 engines in Skyraiders ( source for Rare bears first engine?) were rated at 2700hp for take-off and 2700hp at 3700ft military power dry.
> 
> ...



I've done some research on Rare Bear in trying to find out how the 3350 was configured for the climb record (was it stock, was it modded, and if so, how much, etc.) So far I haven't been able to find out much about it...


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## Shortround6 (Aug 5, 2014)

grampi said:


> Yep, a Thunder Mustang would require a blower to be competitive in this event...I didn't take into consideration what altitude does to engine performance...



A _very_ general rule of thumb is about 2% less power per 1000ft.


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## davparlr (Aug 5, 2014)

Shortround6 said:


> One clue is the 24,000ft service ceiling.
> 
> Another is getting 640hp from 601 cu in at 4800rpm. Anybody got any details on _IF_ the engine has a supercharger?
> 
> Since the air at 10,000ft is 73.8% as dense as it is at sea level the engine will make 73.8% of the power _unless_ the supercharger set up is rigged to accommodate the pressure/density drop.



A Falconer site says the engine is capable of 1600 hp with turbo or supercharger. Would nitromethane provide the hp? I have read it will provide 2.3 times the power of equivalent quantity of gasoline.


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## GregP (Aug 5, 2014)

When they actually extract 1,600 HP from the Falconer, it doesn't tend to last long. It was never designed for that power level.

The parts LOOK beefy until you see them next to Allison rods in a racing Merlin alongside the other Merlin parts. Then they look positive spindley and tiny.


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## Shortround6 (Aug 5, 2014)

The engine may be capable of that for short term ground use. 

We are now getting into a very grey area of use for aircraft. 

FlyboyJ or Greg or some others on this forum may have a much better Idea of what is _allowable_ for general aviation use and what is allowed for racing use in aircraft engines.

Also remember that what an engine may tolerate for a 6-12 second drag race or even a tractor pull may NOT be what it can tolerate for 90-120 seconds in a hard climb in an airplane.


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## GregP (Aug 5, 2014)

Most of the FAST racing aircraft are in the Experimental or Experimental Exhibition category and can pretty much do what they want. Most of the top warbird teams have a race engine or two and a "cruise around" engine or two. They install the cruise around engine to get to Reno and get home from Reno. The race engines are in the plane for one or two weeks a year. It is hoped that they will be going so fast when they finish the race or break that the pilot, should the outcome be "break," will be able to swap airspeed for altitude and get the beast on the runway. Mostly, they DO.

Sometimes not, and sometimes with very bad results.

No Top Fuel drag race engine will survive more than about 5 - 7 seconds of operation (the spark plugs are basically gone and the engine diesels for the last few hundred feet of a normal run, which is 1,000 feet these days, so they are completely useless for aircraft operation. Any Merlin at Reno will put out 1,500 ± HP for much longer than the 5 minutes Rolls Royce claimed. It will likely put out out 1,500+ HP for over two hours, maybe as many as 100 hours. At 3,850 HP it will be fine for 2 - 3 laps and then will be heat-soaked, and will have to either be throttled back or die. Many have done just that. So have other engines that are pressed WAY beyond design limits. The R-3350 is VERY tolerant of high manifold pressure but is also very INTOLERANT of any rpm that reaches 3,000 or over. If you hit 3,000 rpm, you will be flying scrap metal going downward shortly after reaching that rpm.

The R-3350 in Rare Bear can put out 4,000 HP on normal, regular air and probably 4,250 - 4,400 HP on Nitrous Oxide. It will cruise around at 3,500 - 3,600 HP for probably DAYS or weeks. It will survive 4,200 HP for probably 15 laps if they had the Nitrous capacity to do it, but they only carry enough for 2 - 3 laps ... that is IF they use it. Since Rod Lewis bought the plane, they have not used Nitrous in a Reno Gold Final race. Lyle Shelton almost alwyas DID use it, but never admitted it. You could tell because the NOS truck would pull up when the Bear got back to the pits and the exhaust turned dirty brown on the last two laps as he picked up speed ... a sure sign of Nitrous Oxide.


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## davparlr (Aug 6, 2014)

see next post


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## davparlr (Aug 6, 2014)

Yes, but could a Falconer engine pull 1000 hp for a reasonable amount of time for a climb record attempt and, since nitromethane does not need much air, maintain that 1000 hp to 10k? If so, maybe the Thunder Mustang could beat the record, or, maybe another special designed aircraft.

Also, how about a NASCAR engine? They generate over 850 hp on 110 octane gas for several hours at a high load level. Add some nitrous to get some more power and maintain a good level of hp up to 10k and you might have a power plant to break a record.


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## Shortround6 (Aug 6, 2014)

From Wiki: Nitromethane - Wikipedia, the free encyclopedia

"The amount of air required to burn 1 kg (2.2 lb) of gasoline is 14.7 kg (32 lb), but only 1.7 kg (3.7 lb) of air is required for 1 kg of nitromethane. Since an engine's cylinder can only contain a limited amount of air on each stroke, 8.7 times more nitromethane than gasoline can be burned in one stroke. Nitromethane, however, has a lower specific energy: Gasoline provides about 42–44 MJ/kg whereas nitromethane provides only 11.3 MJ/kg. This analysis indicates that nitromethane generates about 2.3 times the power of gasoline when combined with a given amount of oxygen."

It also means you need about 4 times (or just under) the weight of nitromethane for the same power as gasoline. Switching fuels in flight is not practical without a complete secondary fuel system. For a 5-10 minute record run it might be possible, it is going to ake longer to descend and land that than the climb up.

" Exhaust gas from an internal combustion engine whose fuel includes nitromethane will contain nitric acid vapour, which is corrosive, and when inhaled causes a muscular reaction making it impossible to breathe. People exposed to it should wear a gas mask."

Which is not really a problem for the pilot as he may be on oxygen anyway. It may be a problem for the aircraft unless quick washdowns/decontamination are done on landing. 

"Nitromethane was not known to be a high explosive until a railroad tanker car loaded with it exploded on June 1, 1958.[6] After much testing it was realized that nitromethane was a more energetic high explosive than TNT, although TNT has a higher velocity of detonation and brisance. Both of these explosives are oxygen poor and some benefits are gained from mixing with an oxidizer, such as ammonium nitrate. Pure nitromethane is an insensitive explosive with a VoD of approximately 6,400 m/s (21,000 ft/s), but even so inhibitors may be used to reduce the hazards. The tank car explosion was speculated to be due to adiabatic compression, a hazard common to all liquid explosives. This is when small entrained air bubbles compress and superheat with rapid rises in pressure. It was thought that an operator rapidly snapped shut a valve creating a "hammer-lock" pressure surge."

may or may not be a problem. 

and 

"Nitromethane is usually used with rich air/fuel mixtures because it provides power even in the absence of atmospheric oxygen. When rich air/fuel mixtures are used, hydrogen and carbon monoxide are two of the combustion products. These gases often ignite, sometimes spectacularly, as the normally very rich mixtures of the still burning fuel exits the exhaust ports. Very rich mixtures are necessary to reduce the temperature of combustion chamber hot parts in order to control pre-ignition and subsequent detonation. Operational details depend on the particular mixture and engine characteristics."

A reason for the long zoomie headers on fuel dragsters. Get the flames away from the car body. Drag of 2-3ft long header pipes on an aircraft???

Regular Methanol is a much better fuel for record setting aircraft. It is a _lot_ less _twitchy_. It allows for more power than gasoline because you can burn twice as much per pound of air and it has a lower flame temperature than gasoline which helps with the cooling load. 

The nascar engine may need a supercharger as the engine will loose almost 20% in power by the time it reaches 10,000ft. 

The difference between drag cars ( or even nascar racers) is that the driver can _walk_ back to the pits after an engine failure. 







Out of 20-30 Nascar engines starting a race how many drop out due to engine failure _every_ race? even if it's only 2-3 per race?

Pilot interview for 0-3000meter climb record flight:
Team manger to pilot "well, Jim Bob (pilot) we reckon we got a good chance of setting the record, we got the power and we figure that there is only about 10-20% chance of the engine grenading on any given record attempt flight. Pay is $1000.00 a week, $500.00 a record attempt flight with a bonus for setting the record and we provide the parachute and repacking of the parachute at no cost to you. Whatdo you say? take the job?" 



However.


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## davparlr (Aug 6, 2014)

Shortround6 said:


> It also means you need about 4 times (or just under) the weight of nitromethane for the same power as gasoline. Switching fuels in flight is not practical without a complete secondary fuel system. For a 5-10 minute record run it might be possible, it is going to ake longer to descend and land that than the climb up.



I’m not sure this would be a big issue for a record run.



> " Exhaust gas from an internal combustion engine whose fuel includes nitromethane will contain nitric acid vapour, which is corrosive, and when inhaled causes a muscular reaction making it impossible to breathe. People exposed to it should wear a gas mask."
> 
> Which is not really a problem for the pilot as he may be on oxygen anyway. It may be a problem for the aircraft unless quick washdowns/decontamination are done on landing.



But, this is done regularly during drag races so the technology and physiology is well known.



> "Nitromethane is usually used with rich air/fuel mixtures because it provides power even in the absence of atmospheric oxygen. When rich air/fuel mixtures are used, hydrogen and carbon monoxide are two of the combustion products. These gases often ignite, sometimes spectacularly, as the normally very rich mixtures of the still burning fuel exits the exhaust ports. Very rich mixtures are necessary to reduce the temperature of combustion chamber hot parts in order to control pre-ignition and subsequent detonation. Operational details depend on the particular mixture and engine characteristics."
> 
> A reason for the long zoomie headers on fuel dragsters. Get the flames away from the car body. Drag of 2-3ft long header pipes on an aircraft???



I think there are several mitigating issues here. First, the exhausts are designed to provide down force for the dragster, which would require over a 90 degree turn with correct radius. I am sure this is part of the reason for the length. I would suspect that this length would be less for a turn to provide thrust rather than down force. Also, the exhaust energy for a 1000 hp nitromethane engine would be much less than a 8,000-10,000 hp dragster engine so I suspect exhaust length would be significantly reduced. Finally, best climb speed for, say, the Thunder Mustang, is less than 200 mph, which, while still important, drag is considerably less of an impact than on top speed, for instance. 



> Regular Methanol is a much better fuel for record setting aircraft. It is a _lot_ less _twitchy_. It allows for more power than gasoline because you can burn twice as much per pound of air and it has a lower flame temperature than gasoline which helps with the cooling load.



I am certainly not an engine specialist, as I consider you to be. I have for the most part been throwing mud against the wall, so if I was to build a plane to attempt to beat the 10k time to climb record, I certainly would cede expertise to your opinion over mine any day. 



> The nascar engine may need a supercharger as the engine will loose almost 20% in power by the time it reaches 10,000ft.



Maybe. However, if it was using nitromethane, and the engine was limited to 1000 hp, (for no more than three minutes) it may be possible to maintain the 1000 hp up to 10k by simply throttling up. This maybe also be true with methanol (with nitrous?). This may be effective for the Falconer and the NASCAR engines. I don’t know about the Falconer but the NASCAR engines are run at full power for nearly three hours with power cycling. I think these are really tough engines and uprating them to 1000 hp for three minutes does not seem unreasonable. In addition, there should be plenty laying around to mod for a plane.



> Pilot interview for 0-3000meter climb record flight:
> Team manger to pilot "well, Jim Bob (pilot) we reckon we got a good chance of setting the record, we got the power and we figure that there is only about 10-20% chance of the engine grenading on any given record attempt flight. Pay is $1000.00 a week, $500.00 a record attempt flight with a bonus for setting the record and we provide the parachute and repacking of the parachute at no cost to you. Whatdo you say? take the job?"



I don’t know, I think historically, there have been many pilots, climbers, drivers, etc., climb into a vehicle to attempt to set a record, achieve an accomplishment, win a race, or go into space, in an event far more dangerous than this would be.


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## GregP (Aug 6, 2014)

I think the Falconer engine could be set up for a world climb record attempt, but these Thunder Mustangs are all privately owned units and anyone who spends the hours required to build one wants to keep flying it. So, I think the trick would be to offer up two Falconer record attempt engines and assure the owner that he would have a functioning engine when the fun was over, not to mention a functioning propeller.

Some owners might well want to take the change if they were using someone else's engine and prop for the attempt and if the costs were covered.

The trick would be to come up with the ~$750,000 USD for the record attempt plus the money for the race engines and prop, plus costs for the record attempt for the crew and owner.

If there is anyone out there who wants to attempy it and has a spare $2M USD, let us know and we can find a Thunder Mustang ownewre willing to give it a try.


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## grampi (Aug 7, 2014)

GregP said:


> I think the Falconer engine could be set up for a world climb recorf attempt, but these Thunder Mustangs are all privately owned units and anyone who spends the hours required to build one wants to keep flying it. So, I think the trick would mbe to offer up two Falconer record attempt engines and assure the owner that he would have a fuinctioning engine when the fun was over, not to mention a functioning propeller.
> 
> Some owners might well want to take the change if they were using someone else's engine and prop for the attempt and if the costs were covered.
> 
> ...



I guess I don't understand why the cost of making a record breaking attempt is so high...and I'm not talking about the cost of the aircraft, or the things that are done to the aircraft (that stuff has always been expensive), I'm talking about the cost of the organization or agency responsible for timing, recording, and verifying the attempt...what's the expense? I realize it's not just a couple of guys with a stop watch and pair of binoculars, but $750K? That's just nuts!


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## GregP (Aug 8, 2014)

The FIA guys don;t work for nothing. You pay their costs for transportation, lodging, meals, incidentals, rent-a-cars, etc, plus their fees. You have to rent a suitable course (NOT cheap) and it has tro be equipped with specified equipment accurate enough to measure the records being sought. You pay for the site, the equipment, and the people to run the equipments, plus the witnesses. You pay for your own team's time, lodging, meals, vars, gas, laundry, etc.

By the time you are done, it is well over $800k - $1.5M US dollars. Ay least taht's what it was going to cost for the Strega attempt at a world speed record, so they scrapped the plans and never made the attempt despite that fact that Strega can hit 540 mph any day of the week in a straight line.

The reason more records aren't attempted is the cost. It USED to be much easier and MUCH cheaper, and then technology came around and now the powers that be want their precious records verified by the best instruments money can buy or rent. Makes record attmpts many fewer and farther between.


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## grampi (Aug 8, 2014)

GregP said:


> The FIA guys don;t work for nothing. You pay their costs for transportation, lodging, meals, incidentals, rent-a-cars, etc, plus their fees. You have to rent a suitable course (NOT cheap) and it has tro be equipped with specified equipment accurate enough to measure the records being sought. You pay for the site, the equipment, and the people to run the equipments, plus the witnesses. You pay for your own team's time, lodging, meals, vars, gas, laundry, etc.
> 
> By the time you are done, it is well over $800k - $1.5M US dollars. Ay least taht's what it was going to cost for the Strega attempt at a world speed record, so they scrapped the plans and never made the attempt despite that fact that Strega can hit 540 mph any day of the week in a straight line.
> 
> The reason more records aren't attempted is the cost. It USED to be much easier and MUCH cheaper, and then technology came around and now the powers that be want their precious records verified by the best instruments money can buy or rent. Makes record attmpts many fewer and farther between.



It's too bad the cost is so high as there would probably be more attempts, and more new records being set all the time. I think Rear Bear's speed record would've been bested years ago as there have been faster planes (like Strega and Dago Red) since that record was set. Breaking Bear's climb record wouldn't be so easy, and if another plane did break that record, I'm sure Bear would be able to set a new record...but with costs being so high, many of the records will stand even though there are planes that can beat those records...


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## GregP (Aug 8, 2014)

Yeah. Seems like the people who sanction world records want to make a huge profit from ANY new record these days instead of merely track the progress.

Perhaps somone should strat a NEW organization with the aim oif restoring low-cost attempts at world records recognized by that body. Once a few of the present-day world records have been beaten and recognized, the new group would have instant repectability by virtue of having verified faster records at much lower prices. The cost of the course won't change much unless the new orgainzation owns some land in various places that are receptive to world records for a particular sport, but the number of people reuired to set a new record could be cut in half, and the fees could be made more reasonable by a small organization. The costs could easily be half or less of what iot costs now.

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## tomo pauk (Sep 1, 2014)

Sorry for such a late reply 



tomo pauk said:


> Looks to me that WER in second S/C gear was not running on full RPM.





Shortround6 said:


> Supercharger doesn't have a choice does it? if it is in high gear it is turning 9.45 times as fast the crankshaft. You can close the throttle plate to restrict the boost/power.



The thing is that S/C will supply less of the compressed air in case it's rotating speed is lower, and it will be turning on slower rate when the crankshaft is also rotating slower. Less compressed air - less power at altitude. We can remember that BMW 801C did also featured restricted RPM in higher gear, for the highest power setting. So did initially the 2-stage R-1830, for military power?


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