Quote:
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.