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Senior Member
Join Date: Jun 2000
Location: N. Phoenix AZ USA
Posts: 28,977
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Quote:
Originally posted by Jared Fenton
Some of the older helicopter engines, like Franklins. I'm no expert on piston driven planes, though.
More interested in jet engines
I dont see how a piston driven airplane could be high performance. Correct me if im wrong, but dont they usually only spin up to 3-4000 RPM?
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Do not believe that Franklins had hyd valves...
Typical aircraft piston engine turns max 2600-2700. Problem is that the prop is bolted directly to the crankshaft and any faster than that and the tips of the propeller go supersonic. This is not good and causes them to lose lift (thrust) and also it vibrates, causing pieces to eventually fall off, like tips of the prop. This results in an imbalance and then bigger pieces fall off, like the engine, then the plane goes down.
There are a few gear driven engines, with a gear box that allows the engine to run at a higher rpm (more power) while the gearbox allows the prop to remain at slower speeds, but these are few and far between. The Continental GTSIO-520 on the Cessna C-421 is one version of this type of engine.
Joe A
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2021 Subaru Legacy, 2002 Dodge Ram 2500 Cummins (the workhorse), 1992 Jaguar XJ S-3 V-12 VDP (one of only 100 examples made), 1969 Jaguar XJ (been in the family since new), 1985 911 Targa backdated to 1973 RS specs with a 3.6 shoehorned in the back, 1959 Austin Healey Sprite (former SCCA H-Prod), 1995 BMW R1100RSL, 1971 & '72 BMW R75/5 "Toaster," Ural Tourist w/sidecar, 1949 Aeronca Sedan / QB
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