On Tue, 27 Apr 2004 14:10:09 -0500, Dave Driscoll
wrote:

The thrust of my point was not to imply
that automotive engines cannot be successfully modified for use in
aircraft, they quite conclusively can, but rather to demonstrate some of
the challenges that can be encountered in making any required
modifications and what those modifications might be.

I understand.

The engine I'm attempting to use is the Ford 3.8L V6. This engine was
originally modified by David Blanton back in the early 70's. I
hesitate to mention his name because he got mired in controversy
towards the end of his life claiming really exhorbitant horsepower for
the engine as used in the airframe.

The 3.8 needs a different cam in order to develop the power it should.
You can also install Wiseco pistons which create a 9 to 1 compression
ratio. Some guys haven't changed the pistons and managed to fly
anyway.

My understanding is that the new V6, the 4.2, is capable of being used
as is, without any modifications, which means not changing the cam. I
don't know that for a fact, it was stated to me by Jerry Schweitzer,
who has built a number of Ford engines and flew behind the 4.2 in his
RV4. He knows more about the engines than I do.

The intake manifold needs some modification and the carburator should
have the McNeilly leaning block installed so you can lean out the
mixture as you climb.

Some guys use the original fuel injection and electronic ignition. No
one engine is modified in the same manner, it's part of the problem of
knowing what to do.

One thing that is or should be common is safety wiring all external
and some internal bolts so that they cannot back out.

Not everyone does this.

Corky Scott