P&W 1830 in Brewster F2A

[ssnider]

A multi question what if. According to an article I read a while back on the internet about the Brewster Buffalo, both Brewster and Grumman whent back and told BuAer they specified engine (Pratt & Whitney R-1535-72 ??) was not powerfull enough. Both requested authorization to use the P&W 1830. The article went on to say Grumman's request was granted, while Brewster was told they had to use the Wright R-1820 if they wanted to change. (Note the articale also claimed Seversky requested to make design changes that were denied as it approved Grumman resupmitting a monoplane design in place of the XF4F1.) Is any of this true?



I did find this under 1936: "10 July The Chief, Bureau of Aeronautics, approved a program of improvements to the F4F and F2A fighters being developed by Grumman and Brewster. Most important were the conversion of the Grumman design from a biplane to the monoplane XF4F-2 prototype for the F4F Wildcat of World War III, and the installation of larger engines in both, which promised a top speed of 300 mph."

https://www.history.navy.mil/content/dam/nhhc/research/histories/naval-aviation/pdf/part04.pdf



What if the Brewster XF2A1 had been built around the P&W R-1830-66 used in the XF4F2?

What is the weight difference between the P&W R-1830-66 and the Wright R-1820-22?



The smaller diameter of the P&W engine would rewsult in a thinner fuselage, possibly reducing drag and increasing speed. If so, assumming the design team maintaned the same wing loading, CG, center of lift etc., how much faster would the plane be after the historical wind tunnel clean up?



Part 2: The Navy makes the same changes as resulted in the F2A3 except using the P&W R-1830-76 engine used in the F4A3 and instead of the wet wing tanks ises the same 58 gal. Drop tankes used on the wildcat with the required plumming to the Brewster's hard points.



How much weight gain?

Require longer cowing and effect?



In short, what if the Brewster had been built and evolved around the P&W engine?

 

[Shortround6]

The fat fuselage wasn't because of the size of the engine.

The Wright engine was 1105lbs
The Pratt engine was 1370lbs, had a single speed supercharger and was good for 1050hp at sea level for take off.
Power at altitude for either engine??????

Brewster used ONLY the integral tanks until the F2A-3. All export Brewsters used the integral tanks.
Wildcats didn't get the drop tanks until late.

 

[ssnider]

My understanding is that the fuselage was fatter than the engine but determined by the engine diameter. It was supposed to reduce turbulent flow thus reducing drag.
Ok, the drop tanks entered service about a year after the F2A3 did. The plane gets heavily criticized for the wet wing tanks even though they were intended to be used much like drop tanks for long-range operations only.
So to keep the same wing loading would require about 11 sq. ft. of wing area or ? increased wing span.

 

[Shortround6]

The tank situation is a bit confusing.

ALL of the early F2As and export Buffaloes used the "integral" tanks. They weren't really wet wing.
The "tanks" were the space between the forward and aft spars, the top and bottom wing skin and certain ribs.
There was no fuel in the wing leading edge (at least not yet). Distinction may be small. There were two tanks although the separation in the middle of the plane was minimal. Pilot did have to select left or right tank.

Saved the weight of separate fuel tanks. But difficult to repair or even add self sealing material to (some export Buffaloes did get self sealing material on the outside of the tanks) . Fuel capacity was 160 gallons.

F2A-3 and only the F2A-3 got two 20 gallon self sealing tanks in the wing leading edge, one on each side, and a 40 gallon self sealing tank in the belly of the fuselage.

Since the fuel overflow return line and the reserve fuel line were both plumbed to the same tank the F2A-3 kept the old plumbing and added the new tanks, lines and a new fuel tank selector switch. However the tank without the extra plumbing was fitted with a sealed filler cap and for most normal operations fuel capacity remained at 160 gallons (20 + 20 + 40 + 80 in the old tank). In fact most planes were stenciled with a warning on the fuel filler to the now dead tank that it was only to be filled by orders of the squadron commander.
They may have been used for ferry flights.

 

[don4331]

The original specification for Brewster and Grumman, allowed for either P&W R-1535 or Wright XR-1670 (which never made it past prototypes). So, Brewster might have planning for the slightly larger Wright engine (although it was twin row 14 cylinder as well).

Any yes, BuAer wanted F2A built, not being redesigned so changes that didn't affect performance, but would impact production were refused i.e. allowed aerodynamic clean up, but not strengthening. Which really added to Brewster's issues.

 

[Shortround6]

Back in 1931-32-33 this was thought to be a highly streamline design.

it took a while to get over it.

 

[fastmongrel]

Were the Buffalo and Wildcat built short and tubby for hangar space reasons or was that just the current design philosophy.