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Old January 28th 06, 11:14 PM posted to rec.aviation.homebuilt
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Default Corvair conversion engines


Richard Lamb wrote:
Peter Dohm wrote:


Some pretty experienced people (in VW engines) have said that the valves


are

the weak link, and that much more that 45 HP will melt the valves down, if
run at that level for more than a few minutes.
--
Jim in NC


For what it's worth, I'd have to agree, with the thought that you can
operate at higher power - until - the heads are heat soaked.
Then it's 45 HP or bust.

I think the thinking is that the engine needs to turn up fast to make
maximum engine power. Which may be true drag racing dune buggies.
Grab a gear and spin that puppy up!


Considering the 356/912 Porsche engines have essentially the same
upper end as a Type 1 VW and they operate far higher sustained powers
than that (think a long 100+ mph Autobahn run or the military gensets
they were in designed to make 400 Hz power at continuous power
settings, depending on generator efficiency, between 55 and 70 hp), I
question this theory provided the cooling blower and baffling are
designed for the power in question. But it's easy to prove or
disprove-hang a VW on a oversized generator, hook a dummy load up, and
monitor RPM, power and CHT!

Gen seets make wonderful engine dynos.