Wild_Bill_Kelso
Senior Master Sergeant
- 3,231
- Mar 18, 2022
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Off-the-shelf engines, or something plausible that was not available?What I'd really like to do is make one which is a bit longer and less stout. But I realize that is probably impossible so I'll settle for clipped wings and 150 more horespower. It seems like that should be in reach.
I don't think that P & W was sharing much of anything with Wright. I don't have the exact history of the Wright cooling fins but they wound up being used on the "Later" R-3350s, Later means after the B-19 not the B-29. They were also the part of difference between the 1700hp R-2600s and 1900hp R-2600s.Eventually, though far too late IMO, they came out with the FM-2, with 1350 hp Wright 1820-56. My understanding is that this was made possibly due to technical improvements in cooling fins made during the development of the lager Pratt and Whitney R-2800.
Yes they did. In this case it was using stuff they developed from the R-2800. It was sort of trickle down. Once they developed it for the R-2800 they looked at applying it to the R-1830.can see in the history of the Pratt and Whitney R-1830 double wasp that they did eventually make some variants with 1350 hp
That may depend if you want to slow down the R-2800 any?Could they have gotten the R-1830-75 or 1830-94 working reliably a bit earlier with some more effort?
It may not have had to be as wide but it did have to that tall if you are going to keep the view over nose.I realize they had to accommodate the diameter of the engine, bud did it really need to be that wide all the way back?
Care to post a picture of that aircraft?We must remember, the XF4F-0 was a biplane
Also they "seem" to have kept the supercharger from the R-1830 engine.No replacement for displacement: R-2000 is more/less R-1830 with 5.75" cylinders instead of 5.5". 150 extra ponies at cost of 300lbs weight
We must remember, the XF4F-0 was a biplane - Grumman went too conservative with the upgrade of the F3F.
Off-the-shelf engines, or something plausible that was not available?
Ok, a number of things.
I don't think that P & W was sharing much of anything with Wright. I don't have the exact history of the Wright cooling fins but they wound up being used on the "Later" R-3350s, Later means after the B-19 not the B-29. They were also the part of difference between the 1700hp R-2600s and 1900hp R-2600s.
Wright had done another one of their "redos" of the R-1820 where they kept the bore and stroke and changed just about everything else. Yes they used the new cylinder fins but they also changed the cylinder heads, the crankshaft, the crankcase, and a bunch of the smaller parts. They also used 20 bolts to hold each cylinder to the crankcase instead of the 16 they used on most the cylinders since the early to mid 30s (?). BTW they had to change the crankshaft to get 1350hp out of the -56A, the -56 was good for 1300hp.
Yes they did. In this case it was using stuff they developed from the R-2800. It was sort of trickle down. Once they developed it for the R-2800 they looked at applying it to the R-1830.
That may depend if you want to slow down the R-2800 any?
A 1350hp R-1830 was not going to be a war winner, the R-2800 was.
The next thing is that you don't really gain much. It appears that they didn't change the supercharger much. The power at altitude is not that much different when you consider they increased the Engine RPM From 2700 to 2800 (they change the bearings). On the two speed engine in high gear they went from 1050hp/13,100ft to 1100hp/13,750 ft. Engine also gained about 80lbs.
Things were better on the turbo engines but that is a much harder change for the Wildcat.
It may not have had to be as wide but it did have to that tall if you are going to keep the view over nose.
All of the fuel and oil was inside the fuselage under the wing. Maybe it didn't have to as wide as it was but you are hiding 144US gallons fuel and 11 gal of oil in the belly.
You really don't gain much by clipping wings, and you often loose a lot.
Increased landing speed.
Longer take-off distance.
Decreased range.
Greater turning circle.
Lower Ceiling.
Strangely you can often get a bit better climb rate but that depends on the Altitude/air density. Better at low altitudes vs worse at high altitudes.
Army numbers and Navy numbers are not in sequential order in relation to each other.
Army numbers are in ordered and Navy numbers are in order but there could be 1 - 2 years difference between the Army and Navy numbers.
It was used in a few DC-3s (which tells us nothing) and it was used in a few (8?) pre production B-24Ns with turbos. The rest of the B-24Ns were canceled Here is the extreme of the the number system The USN -72 engine was used the PBY-4, they used a later engine in the PBY-5.When did the R-1830-75 come out, do you know?
Maybe but it is a bit iffy, nobody put a R-2000 into combat plane.Agreed, but I still think there is some space between the 1,200 hp engine and the 2,000 hp
I'm definitely not worried about the 80 lbs for 150 hp. And I think if that extra HP is mostly at lower altitudes, I still like that. It will help with takeoff, it will help with escape maneuvers (diving down to the deck and pouring on the coal to escape), it will help against torpedo bombers, and it will help with initial climb rate at least for the first couple of minutes. Get you up to 6-8,000' a little faster,
They didn't put much effort into R-2000 (only handful of variants), and I haven't seen a 2 stage (and P&W 2 stage is really 3 speed - neutral, low and high on 2nd stage). With >5k produced, it couldn't have been that bad. 1,450hp for the R-2000-7M2 (DHC-4A) is a quite a bit more power.Also they "seem" to have kept the supercharger from the R-1830 engine.
The higher power levels were only available at lower altitudes than the R-1830.
They may have got a bit more power but nowhere near the changes in take-off power show.
Model | F4F-4 | F4F-3 |
Engine | R-1830-86 | R-1830-86 |
Take-Off | 1,200 / 2,900 | 1,200 / 2,900 |
Normal | 1,100 / 2,550 / 0-3,300 | 1,100 / 2,550 / 0-2,500 |
Normal | 1,080 / 2,550 / 3,800 | |
Normal | 1,090 / 2,550 / 11,300 | 1,050 / 2,550 / 12,000 |
Normal | 1,030 / 2,550 / 13,000 | |
Normal | 1,040 / 2,550 / 18,400 | 1,000 / 2,550 / 19,000 |
Military | 1,200 / 2,700 / 0-1,800 | 1,200 / 2,700 / 0-1,800 |
Military | 1,135 / 2,700 / 3,400 | |
Military | 1,150 / 2,700 / 11,500 | 1,150 / 2,700 / 11,500 |
Military | 1,030 / 2,550-2.700 / 15,000 | |
Military | 1,040 / 2,550 / 18,400 | 1,000 / 2,550 / 19,000 |
Doesn't cost much but better for speed than climb.individual exhaust stacks
I am not sure how much is drag from the housing (fixable) and how much is drag from the internal air flowTwo oil coolers
A lot of drag from two gun muzzles and two ejection ports?Keep just 4 HMGs - again 5 mph
Even more adventurous F4F would've have the R-2600 in the nose
Keep just 4 HMGs - again 5 mph and some speed and RoC gain?