4.11 and Engine Overheat

[Robo.]

Originally Posted by -)-MAILMAN-

5000 feet is still too low to be shifting from supercharger 1 (neutral blower) to supercharger 2 (low blower) in the F4U-1 Corsairs. The Real Life Corsairs (F4U-1/-1A/1C/1D) used the R-2800-8 and -8w engines and maintained 44" MAP up to 8000 feet before shifting from neutral blower to low blower then maintaining 48" MAP. This matches exactly the USN Pilot training film for the Corsairs and until v4.11 the game matched this.

Hi Mailman, I said it was around 5000-5500ft at that particular map (Crimea). The MFP is obviously very much depending on the atmospheric pressure and this is actually modelled in Il-2, e.g. your results may vary on a different map.

44'' up to 8000ft.? Which source is stating this as the alt where pilots normally switched from neutral to low blower?

US manual section b ''Power plant'', page 6:

neutral - S.L - 5500ft
low - 16500ft
high - 22000ft

= exactly what 4.11 Il-2compare states and what is also replicable in game in my climb test including best climbing speed and limit temperatures.

With water injection used, neutral blower only up to 2000ft, low from 2000 up to 15000ft. (e.g. page 24 of the British AP2351A manual)

It seems to me that the blower altitudes in 4.11 are pretty much spot on for Corsairs. Coud you please post some sources (preferably links) stating otherwise?

Originally Posted by -)-MAILMAN-

Hellcats used the R-2800-10 and -10W engines and had a different carburetor than those used in the Corsairs. Once source has the Hellcat shifting from neutral blower to low blower at 5500 ft (USN training film uses this altitude) and another source has it at 7000 feet. The Hellcats in versions previous to v4.11 shifted at 5500 feet. Shifting the supercharger at 5000 feet in this version is also too low for the Hellcats.

I have not tested the F6Fs yet. Again, shifting of blowers was fairly complicated, there were certain restrictions in throttle movement in Low and High blower position especially. Also, pilot had to reduce MFP and desirably RPM when switching, actual reaction time varied from plane to plane, and from the atmospheric conditions, that in the first place. Altitudes at normal rated powers should be as follows:

neutral 2550rpm, 44'' - SL - 7000ft
low 2550rpm, 49.5'' - 7000-22000ft
high 2550rpm, 49.5'' 22000ft up

From what I know from the Hellcat FM development, the 1st blower was impossible to set correctly withinh how the game works (I know nothing about that, sorry), and DT simply focused on getting the actual performance and speeds right at any altitude. The blower alt seems to be about 600m too low which is not a biggie considering you have got correct performance now. Hope that helped.