Most valuable Carrier Fighter Of WWII

[michael rauls]

The F4F was manufactured until 1943, the FM was manufactured right up to the end of the war. They (primarily the FM) served in the Atlantic until the last day of the war.


The interesting thing about the F4F, was that it's design was nearly as old as the Bf109.

 

[michael rauls]

The F4F was manufactured until 1943, the FM was manufactured right up to the end of the war. They (primarily the FM) served in the Atlantic until the last day of the war.


The interesting thing about the F4F, was that it's design was nearly as old as the Bf109.[/QUOTE
I guess I shouldn't have called the 109 a latter type that was inaccurate on my part just when I think of a bf109g or k I often kinda think of them as later types due to there performance( a testimony to the ability of the design for capacity to be improved).
I probably should have used the fw 190 for my example. As best i can remember I think there were one or two classes between the types and the the f4f surprisingly held there own.

 

[swampyankee]

Yes I've always found it fascinating how F4fs seemed to be able to hold their own and in some cases even come out on top when pitted against later types that on paper at least doesn't look like they had any business being in the same sky with. The Bf109g for example.

The Wildcat was tough, maneuverable, and actually pretty fast at low altitudes. Consider the anecdote of somebody who flew against it: Sakai found it a much tougher opponent than the other Allied aircraft he fought before he was shot down by a rear gunner in a dive bomber, some of those aircraft doing quite well in Europe and the Mediterranean against German aircraft. The Wildcat could have been developed farther than it was, but the US industry was better run than Germany's, so it could field new aircraft to replace it.

 

[Shortround6]

I am not sure what you could do the F4F that could have improved it to any great extent.
While anything can be improved given enough effort (time and money) sometimes it is better to start over like with the F6F.

The R-1830 and R-1820 engines had both come to a temporary halt in development in 1941 and while both were later improved there was a 1-2 year gap (maybe more for the R-1830?) while other engines were worked on.
The later versions of both engines gained more power down low (or for take-off) than they did performance at altitude so new superchargers would be needed on addition to beefing up the engines and improving cooling.

The next jump in engine size/power is the R-2600 and that is what started the whole F6F development story. Grumman thought it was better to start over than try to modify the F4F to take the R-2600.

 

[michael rauls]

I am not sure what you could do the F4F that could have improved it to any great extent.
While anything can be improved given enough effort (time and money) sometimes it is better to start over like with the F6F.

The R-1830 and R-1820 engines had both come to a temporary halt in development in 1941 and while both were later improved there was a 1-2 year gap (maybe more for the R-1830?) while other engines were worked on.
The later versions of both engines gained more power down low (or for take-off) than they did performance at altitude so new superchargers would be needed on addition to beefing up the engines and improving cooling.

The next jump in engine size/power is the R-2600 and that is what started the whole F6F development story. Grumman thought it was better to start over than try to modify the F4F to take the R-2600.

Good point that at some point it's more productive to move on to a new design than upgrade an older one.
Just a question that has bothered me for a long time pertaining to the Wildcat, the Fm2 had a fairly substantial increase in horsepower( 200 hp i think) and very little increase in weight yet the speed given for the Fm2 is always about the same as the F4f, around 320 to 330. This doesn't seem possible. There's a few of you guys on here that seem to know more than most of the books or articles on the internet ive read so just wondering if anyone here knows if this is accurate.

 

[Shortround6]

The FM-2 got the Wright R-1820 9 cylinder single row radial instead of the P & W R-1830 14 cylinder two row radial.
The HP difference was much smaller, 100hp at take-off to begin with with later engines getting a new crankshaft that allowed higher rpm and another 50 hp. (difference 150hp).
ANd here we have a major problem in quoting take-off horsepower and trying to figure max speed at altitude from it. The R-1830 engine used a two stage supercharger and was still making 1040hp at 18,400ft. The R-1820 engine used in the FM-2 had a two speed single stage supercharger and despite the power advantage down low, was down to 1000hp at 17,000ft.
So the FM-2 had slightly less power at the higher altitudes and had fatter engine (more drag?)
FM-2 might have made better use of the exhaust thrust

from F4F Wildcat (multiple)

 

[CORSNING]

Good point that at some point it's more productive to move on to a new design than upgrade an older one.
Just a question that has bothered me for a long time pertaining to the Wildcat, the Fm2 had a fairly substantial increase in horsepower( 200 hp i think) and very little increase in weight yet the speed given for the Fm2 is always about the same as the F4f, around 320 to 330. This doesn't seem possible. There's a few of you guys on here that seem to know more than most of the books or articles on the internet ive read so just wondering if anyone here knows if this is accurate.

The greater power gave the FM2 a much better low and medium altitude climb rate.
It had a greater initial climb than any F6F or F4U-1/2. I read somewhere (about 30 yr. ago)
that its low speed acceleration surpassed the Corsairs. However there is always the
drag limited issue. The FM2 reached its limit at around 330 mph and it was going to
take a considerable amount of power to push that speed significantly. Wind resistance
is your answer.

 

[michael rauls]

Thanks for clearing that up for me guys. Now i understand how performance can be altitude dependant depending on the supercharger type and how you could have better acceleration and initial climb but not have that translate to much higher max speed.
If I'm understanding corectly seems like the Fm2 would probably have been somewhat faster at low altitude than the F4F though?

 

[davparlr]

I had to vote for the F4F. I like the early birds which held the line against the cream of Japanese pilots who were some of the best in the world, and highly experienced. They weren't the later poorly trained pilots thrown into the battle nor were they the clay pigeon Kamikazes, which the later planes racked up their scores.

 

[michael rauls]

The greater power gave the FM2 a much better low and medium altitude climb rate.
It had a greater initial climb than any F6F or F4U-1/2. I read somewhere (about 30 yr. ago)
that its low speed acceleration surpassed the Corsairs. However there is always the
drag limited issue. The FM2 reached its limit at around 330 mph and it was going to
take a considerable amount of power to push that speed significantly. Wind resistance
is your answer.

Sorry in my last post I didn't mean to gloss over what you said about drag as a limiting factor in top speed for the Fm2 I guess I just got focused on the supercharger dynamic for a bit.

 

[CORSNING]

Sorry in my last post I didn't mean to gloss over what you said about drag as a limiting factor in top speed for the Fm2 I guess I just got focused on the supercharger dynamic for a bit.

Nothing to be sorry for what-so-ever. It is a great thing that we are all able
to come together and answer a question from different angles and perspectives.
That ability as a group has always been what makes this site great.
You done great Michael, Jeff

 

[CORSNING]

I do not at this time have an answer for the most valuable carrier based
fighter of WW2. The Wildcat held its own even when its performance
was outmatched early in the war. In the FM2 model it proved to be a
worthy advisory to Zero right up until the end. The US carrier based
Corsairs came along very late in the war.The F6F was the answer
to the Zero's reign in 1943 and was just a great answer for all the
needs of the USN at that time. But I just can't shake the mystique
the Zero (A6M2 and 3) was able to project in 1941-early 1943.
No other fighter in WW2 I can think of that was able to project its
abilities to and in many ways past its actual abilities like the Zero.
I ain't pickin' one yet. I am just making a very clear observation.
, Jeff

 

[swampyankee]

The R-1820 seems to have had somewhat more development work than did the R-1830, with versions up to about 1350 hp seeing service in WW2, vs about 1200 hp for the R-1830 (don't quote me, and I've not spent much more than 10 minutes looking at this). The R-1830 could have produced more power had the effort been made -- it had about 25% more piston area, and could have been developed to about 1700 hp (this would be at about the same ratio of horsepower to piston area as the R-1820 managed) but there was no perceived need. Conversely, Pratt & Whitney Aircraft could have used the front row of an R-2800 to create a 1200+ hp single-row R-1400 but, again, there was no perceived need.

 

[Shortround6]

The needs were there, the extra engineering man hours were not.

HP per unit of piston area is interesting but it requires a lot of work to get it to happen. The extra 1.375in of stoke on the R-1820 meant that there was a lot more fuel/air being burned per sq in of piston area compared to the R-1830. Granted the R-1830 ran a few hundred RPM faster.

P & W were working on the R-2800 in two different versions (they gave up on the "A" in 1941) the "B" and the "C" and the "C" shared next to nothing except the bore and stroke with the "B". It is the "C" that made that 2800hp from 2800 cubic inches and it needed a turbo charger 100/130 fuel and water injection to do it.
They were also working on the R-2000 to give more power than the R-1830 for transport use, and they had started work on the R-4360 28 cylinder engine (which used the same bore and stroke as the R-2800). Fooling around trying to hot rod the R-1830 was NOT on their list of priorities.
Late in the war some of what they learned on the R-2800 trickled down to the R-1830 and some were built with a 1350hp take-off rating, this required new bearings, new cylinders and new cylinder heads.

The R-1820s that gave 1300-1350hp were another engine that shared nothing except the bore and stroke with the model that preceded it. New Crankcase, new crankshaft, new connecting rods, new pistons, new cylinder barrels with a new way of making the fins and new cylinder heads. They used four more bolts to hold each cylinder to the crankcase than the preceding R-1820.

 

[DarrenW]

It had a greater initial climb than any F6F or F4U-1/2.

I've heard this before but haven't extensively compared the climb rates of the three (I'm very familiar with the Hellcat's climb performance from studying Navy test results, the other two not so much). Is that in both military and combat power?

You're the guy who charts these planes all the time so you should know...

 

[DarrenW]

It is the "C" that made that 2800hp from 2800 cubic inches and it needed a turbo charger 100/130 fuel and water injection to do it.

IIRC didn't the -59 and -63 "B" series engines found in later P-47Ds produce around 2800hp when boosted to 70" Hg while using 104/150 fuel and ADI?

 

[Shortround6]

There wasn't a whole lot of "combat" power to be had from the R-1820 engine in the FM-2.

One book claims 1360hp at sea level at 2600rpm and 52in MAP in low gear, Take-off was 1300hp at 2600rpm and 46.4in of MAP.
Military power was given as 1300hp at 2600rpm at 4,000ft.
Power dropped off to about 900hp at 15,000ft and after shifting to high gear power climbed back up to 1000hp at 17,000ft.

Up to about 9-10,000ft the FM-2 might have 200hp more than the F4F-4 but the F4F has about 100hp more from about 10-15,000ft and except for a brief burp it has 40-50 more from around 17,500 on up. the FM-2 weighed about 7500lbs (or a bit under clean) but was under 1200hp by 6,000ft or so.

No water injection, no WEP except for that 50-60hp boost near sea level.

edit: upon further research water injection seems to have available some time in 1944 but max allowable boost may not have exceeded 52in.?

 

[Shortround6]

IIRC didn't the -59 and -63 "B" series engines found in later P-47Ds produce around 2800hp when boosted to 70" Hg while using 104/150 fuel and ADI?

There is a test saying they could but the test doesn't say if it was approved for service use or not.
P 47D Performance Test Using 44-1 Fuel

It does say there were cooling problems and climbs had to limited to short periods of time (without saying how short?)

The R-2800C as used in the P-47M and N was approved at 2800hp for service use. It ran 100rpm faster than the -59 and -63 "B" series engines and had much better finning on the cylinder heads and cylinder barrels and required something like 10% less cooling air for the same power (?)
It was also rated at 72in of manifold pressure.

 

[DarrenW]

There is a test saying they could but the test doesn't say if it was approved for service use or not.
P 47D Performance Test Using 44-1 Fuel

It does say there were cooling problems and climbs had to limited to short periods of time (without saying how short?)

The R-2800C as used in the P-47M and N was approved at 2800hp for service use. It ran 100rpm faster than the -59 and -63 "B" series engines and had much better finning on the cylinder heads and cylinder barrels and required something like 10% less cooling air for the same power (?)
It was also rated at 72in of manifold pressure.

Very good. Do you happen to know why the Navy's -18W "C" engine never achieved similar MAP ratings/horsepower as the Army's -57, -73, and -77 versions? From what I can tell the greatest boost level authorized in "combat" power remained at 60" Hg (identical to the "B" series -8W and -10W engines). Maximum horsepower of the -18W was boosted to 2380hp at 2800rpm according to AHT (Dean).

 

[DarrenW]

After looking over the data presented at wwiiaircraftperformance.org I could definitely see the initial climb advantage the FM-2 possessed over the other two naval fighters. From all the aircraft testing performed, both the F6F and F4U-1 averaged right around 2,900 fpm at S/L when in military power while the FM-2 averaged over 3,500 fpm in similar settings (although the FM-2 does have a much smaller grouping of data to pick from than the other two airplanes). When flown at combat power the F6F and F4U-1 gained approximately 300 and 400 fpm respectively from the boost in horsepower but they still lagged behind the sprightly FM-2 in either power setting (one test of the FM-2 showed 3670 fpm in combat power). Quite impressive indeed.

FM-2 Performance Trials
F4U Performance Trials
F6F Performance Trials