4 ms·
Car or bike engines are not made to run continuously at 75% of max power with 1500-2000 between overhauls. Otherwise you can put a motorcycle engine in the plan
by AdrianB1 4y ago
Car or bike engines are not made to run continuously at 75% of max power with 1500-2000 between overhauls. Otherwise you can put a motorcycle engine in the plane, even better power to weight ratio (200 HP/liter) than car engines, but it does not work.
- cduzz 4y agoThis article suggests that they started with a marine engine, typically an automotive engine that's been modified for these duty cycles by changing cams, timing, bearings, etc. Probably not all existing automotive engines are well suited to these applications, but they only need one or two. Obviously an aviation application has other added constraints like elevation changes, inverted operation, packaging requirements, etc, but "runs at 75% max power for hours at a time" is certainly in common with the marine applications, and trivially demonstrated on a dyno stand.
- AdrianB1 4y agoGA does not fly inverted; elevation changes are influencing mostly the air mixture. Just saying, not contradicting.
- cduzz 4y agoOld marine applications would use carburetors and often those carburetors weren't at all suited to changes in elevation. (Most of my knowledge is actually only of a specific family of Volvo / Penta pushrod engines) Probably airplanes, even in GA situations, are able to operate under negative Gs far more often that a typical marine application.... A person adapting such an engine would ideally think about oil pickup under such scenarios.