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Old February 5th 06, 08:38 PM posted to rec.aviation.homebuilt
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Default Corvair conversion engines

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


It is a trick to see if you are overheating, with the typical VW or
Corvair instalation, since most have no way of monitoring CHT, or more
specifically, the valves, seats and guides.


Jim from what I've read (no personal experience!) it is not that difficult
to hook up a cht to a VW and they (whoever they are!) suggest attaching

the
sendor near the exhaust valve part of the head and limiting the cht to (I
think) 400 degrees or less. This is the part that limits VW's to less

than
40 -45 hp. Of course anything you can do to remove heat faster will let

you
run at a higher output. Such as proper baffling and external oil cooler

etc
etc. Nothing is wrong with using a VW or Corvair engine but you should be
knowledgable of their limitations!
John

As an aside, both a 1600 and a 2180 VW can put out 40hp continuous if
properly set up but the 2180 will be loafing while doing it at a lower rpm
which will let you use a bigger prop and limit you max rpm.
Life's all a big tradeoff! ;-)

There used to be, this is 35 year old info, a CHT sender that replaced the
copper spark plug gasket. At the time they were popluar with the Hot Rod
and SCCA crowd for both VW and Porsche engines. I have no idea whether they
are still available, nor there cost or level of accuracy.

As to the lower RPM option with a bigger prop on the VW 2180 conversion;
please promise that you will also install, and use, a manifold pressure
gauge. Two of the guys I know that broke VW cranks at less than 200 hours
were operating at what they believed was a conservative RPM--without
measuring manifold pressure...

Peter


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