J. Clarke wrote:
Morris Dovey wrote:

Hmm - In my ignorance, I have to wonder how well a low compression
engine would fare at 8000'/2400m. Would that work?

Diesels typically have compression ratios from 14:1 to 24:1. Few
gasoline engines go higher than 12:1 and most considerably less. The
Continental O-200 has 7:1, the Lycoming O-235 has 8.1:1. Both are
very popular aero engines that work fine at 8,000 feet. The
Rolls-Royce Merlin that powered the Spitfire had 6:1 but it also had a
blower.

(I played with diesel model aircraft engines in the 50's, but they
ran at fairly high compression.)

All diesels run at high compression--it's the nature of the beast that
they have to.

Thanks, John. The mention of a low compression aircraft engine confused
me - I suppose a 14:1 might be a "low compression diesel" then, even
though that might be fairly high for a gas engine. IIRC, my old Volvo
B20 (gasoline) engine had a compression ratio of 11:1, which I was told
was fairly high for a car.

I appreciate the info.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/