Post by miletus12 on Jan 19, 2022 3:01:11 GMT
Okay, here is the leadoff and it is a "controversial" one. Fuel injection was not a feature of British aero-engines at the beginning of WWII (1938ish in the timeline). Why was that decision made?
Problems; for airplane carburetors
a. freezing. The 6% loss of ICE engined aircraft due to carburetored engines holds down to the present. Americans develop a Bendix forced injection carburetor in 1940.
b. the carburetor float jams when the planes inverts.
c. gumminess of safety fuels fouls the fuel feed lines.
d. British screw up their testing program and they abandon their own fuel injection program. George Borman warns the British after his sit-down with the Americans, go fuel injection or else. A Doctor Morley, at the British air ministry's Royal Aircraft Establishment, nixed the British programs. NACA sent their own reports and the British air ministry ignored those reports (as they did about US research about wing chords, propeller and even swept wings, if one can believe it!)
The upshot? About 20% loss of power for the aero-engine. The German DB601 by direct fuel injection boosts Watts output by 20%. That crashes in the UK in 1939. Rolls Royce gets the SHOCK of their lives. Then they tested their carburetor fitted to the Merlin. The SU series they tested in a tilt test choked out.
June 1940 captured Jumo engine is tested. Fuel economy and so Beatrice Shilling designs a British pressurized carburetor. This is almost a duplicate of the Americans' work, but it is British. Wonder if she saw a Bendix fitted to a PRATT?
British finally figure it out. Fuel injection is applied to the Bristol Centaurus. Now this is 1945.
And that is the reason a Warhawk or a Wildcat could hang with a BF 109 in a rolling scissors and kill it, while a Spitfire (At least before Beatrice Shilling's pressurized carburetor in 1943.) would choke out at the top of the negative gee loading, fall off in power and be blasted out of the skies.