4.11 and Engine Overheat

[Whacker]

Originally Posted by -)-MAILMAN-

Originally Posted by Robo
"I just did a quick test in WIP 4.11.1 and you definitely will be able to fly her by the book now - cold start, taking off at full power (99p no ADI), maintaining climb power of ''44 @ 2550RPM to 5000ft."




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.

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 the actual pilot manual for the F4U-1 series open right now, revision 1944.

The climb section calls for the following:

Max continuous normal rated power calls for 44" MAP at 2550 RPM, with the blower shift from neutral to low when MAP drops to 41.5" between 5500 and 7000 ft. above MSL.

Military power climb calls for 2700 RPM at 52.5" MAP, shifting to low blower when MAP drops to 45" between 1700 and 5500 ft. above MSL.

Edit - I posted this for discussion sake, not to indicate that anyone is wrong or right.

[Pips]

Originally Posted by Whacker

I have the actual pilot manual for the F4U-1 series open right now, revision 1944.

The climb section calls for the following:

Max continuous normal rated power calls for 44" MAP at 2550 RPM, with the blower shift from neutral to low when MAP drops to 41.5" between 5500 and 7000 ft. above MSL.

Military power climb calls for 2700 RPM at 52.5" MAP, shifting to low blower when MAP drops to 45" between 1700 and 5500 ft. above MSL.

Whacker, does the manual make any mention of radiator settings for the above? Does it also cover temps and times at certain RPM before overheating sets in? Cheers.

[Whacker]

Originally Posted by Pips

Whacker, does the manual make any mention of radiator settings for the above? Does it also cover temps and times at certain RPM before overheating sets in? Cheers.

No specific radiator settings are mentioned for those two profiles. Also no clear answer to your second question. Here's some data that seems to be relevant.

- There's no air speed restriction regarding any of the cooling flaps (cowl, intercooler, oil cooler) and apparently they can be open at any speed up to Vne, and are covered by some kind of "relief system".

- Max open cowl flaps can lead to some buffeting at the tail, so it's recommended they only be full open on the ground. Take off and climb are recommended at 2/3 open, and high speed or cruising are recommended full closed.

- Max cyl head temp *period* seems to be 260 degrees C (500 F), and the manual says at several places *never* to exceed that under any circumstances.

- Max rated continuous power cyl head temp is stated to be 232 degrees C, with the provision that 260 never be exceed as per previous bullet point.

- Take off and Emergency War Power engine profiles are to be used for no more than 5 minutes.

- Re: Emergency War Power, it doesn't say whether this is 5 minutes max per flight (and between ground servicing) or if it can be used multiple times. I imagine the Wasp radial ground service manual would be the authority for this. It's also clearly limited by the amount of water in the water tanks, but I can't determine if the total water capacity would be used up during that 5 minutes or not.

- Military Power is to be utilized for no more than 30 minutes. Again it doesn't say if this is the total per flight or if it can be used, let to cool down, then used again.

- If I had to make a semi-educated guess given what I know about radials, the 5 min/30 min limits for those power profiles is per flight, with some ground maintenance and checks that need to occur before the engine can be used again. Radials had rather low mean time between overhauls, and higher power settings and temperatures are going to cause rapidly increased wear and tear the worse it gets.