I don't really want to get into this discussion, because it will lead me to do 10 hours of backup research, rather than 10 hours of KR work, but I've always thought that a unless it was deeply finned (inside and out) a larger oil pan didn't do a lot for you other than give you a slightly larger oil quantity reserve (in case you develop a leak). But they also SLOW your warmup time, therefore increasing wear in the first few minutes after starting the engine. Once "steady state" is reached, you're just carrying extra weight (in the form of oil) around. Oil temps will not be improved over a smaller one once steady state is reached. Larger pans are also handy for race cars that need baffling to keep the oil from sloshing to somewhere other than the middle during hard cornering and braking. Theoretically, airplanes should be kept with the ball centered and are usually close to horizontal in the longitudinal axis, so that's not a biggie for us, especially KR pilots. WW said his Piet, which sits pretty nose high (unlike the KR), never starved for oil under any circumstances, using a stock sump. I've heard him say that the stock steel flat pan is perfectly adequate for aviation use. Having said all that, I have a deep pan, mainly because my steel one was hideously deformed, and for the extra few minutes I'll gain if I develop an oil leak, not for any expected improvment in cooling (other than the fact that aluminum conducts heat better than steel, and there's more surface area in a deeper pan).
Here's a statement out of Fisher's "How to Hotrod Corvair Engines": "improving the flow of oil reduces bearing temperatures". That's taken totally out of context, but he also recommends a larger oil pump. This guy wrote the "Bible" on Corvair engines, as far as I'm concerned, and I feel sure his statement is based on experimentation with Corvair engines. As has been mentioned on CorvAircraft though, this will increase loads on the distributor's pump gear drive pin, and early style pins have been known to shear. Later versions are stronger, and should fare better. I don't see how a high pressure pump could "wash out the bearings" any faster than a regular pump, since any excess pressure is regulated to a preset level by the oil pressure bypass valve that Mark's already mentioned. The bearings simply never see any extra pressure in this case. It may very well be true that the oil may get slightly hotter due to extra "work" being peformed on the oil, and some small amount of power is wasted, IF the pressure is unecessary to achieve adequate flow. But on the other hand, if bearing clearances open up, with a higher output pump you'll have more " headroom" before the bearings starve for oil and something nasty happens. That might get you to the airport before the fan quits and the pilot starts sweating. I guess the bottom line is that I don't see any compelling reason to condemn anybody from having a higher volume pump, or for what kind of oil pan they are running. Either way is a compromise in one or more directions. I just got off on an hour of reading "How to Hotrod Corvair Engines". This thing is just chock full of handy information. Now I know where many of the experts get their expertise. It's no longer in print, but I got mine off of ebay 5 years ago for $8. There are two copies there right now, one for $16 "buy it now". And a Google search will turn up enough $20 copies for everybody that's thinking about building a CorvAircraft to have one this week. Worth 5x the price, easily... Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net --------------------------------------------------------------
