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Old February 8th 06, 12:45 AM posted to rec.aviation.homebuilt
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Default Corvair conversion engines

On Sat, 4 Feb 2006 22:34:36 -0500, "Peter Dohm"
wrote:

"UltraJohn" wrote in message
hlink.net...
Morgans wrote:


"D.W. Taylor" wrote

I drove a harvesting machine that used hydrostatic drive and a VW

engine
for power. We ran it on a governer at 3950rpm 24x7 all summer. \\\

The fact that it ran with a governor means that it was not at full HP.

It
is admirable for it to run that many RPM's for that many hours, but

still,
there is no indication of how long it would run at true Wide Open
Throttle, making all the HP it could.

I suspect its life would have not been as long, if it were loaded to

it's
maximum output.


Jim
What airplane POH tells you to run your reciprocating engine at max/wot
throttle?
Most small airplanes run max hp for about 10 to 30 minutes for takeoff and
climb then throttle back to 75% for cruise. So expecting a VW/corvair to

go
max for hours on end and not break is unrealistic. I personally think
either engine is viable in the proper application and treated properly.

One
of the first things in your testing phase is to make sure your not
overheating the thing. It's quite well known a VW is not capable of
continuous operation at much more than 40 or 45 hp (let's see 75% of 65

(65
being about the highest you'll want to run a VW) is 49 hp) so your

probably
only going to cruise at about 65% power which is not bad because you still
have that extra reserve for takeoff and go arounds!
I don't know what the max continuous of a corvair is but the same applies,
run it at the right level and you'll probably have a sweet little smooth
engine! This is homebuilt/experimental right? ;-)
John

I don't know what the Corvair can really do either. But expect 40-50
percent more than an 1800cc (slightly overbored) VW. I really think I'd
cruise at more like 60 percent power, at most. I agree about that sweet
smooth little engine though, and the choice will have to depend on parts
availability and how fast I really think it has to fly when I get to that
point. 120-130 Kts should be readily feasible for the Corvair.
Peter

65hp continuous is no problem for a Corvair even 80 HP should be
reasonable.- it has significantly better head fin area than the VW.The
engine is designed as a 110 (or even 140) hp normally aspirated
engine, and in vehicle application, including the huge CorVan,
overheatiing was not a significant problem.

90HP at 3000 RPM is not a stretch at all, and at 2800 RPM cruise, even
if that was full throttle (max output for the RPM) we are talking 85
HP.