There is a good article in the latest issue of "Kitplanes" ("Certified
vs. Homebuilt") about the Chevy conversion package.

"Bruce A. Frank" wrote:

Matt,

The GMC 4.3L V-6 engine has been dependable with some minor after market
mods. As built by most it produces about 230 to 240 hp (and one I know
of that is producing 300 hp). The draw back is the weight. It is stock
with cast iron heads (versus the Ford's aluminum heads) and the after
market aluminum heads cost close to $2000 once the machine work is
finished.

The CG of both the Ford and Chevy V-6s, even with the PSRU is closer to
the firewall than the CG of the equivalent power Lycoming. The real
concern of mounting heavier engines is the moment on the mounting points
on the firewall. Overall CG of the plane can be adjusted, usually, with
placement of the battery.

In general, the Chevy, coming along after the development of the Ford
conversion and therefore benefiting from that prior art, manifest fewer
idiosyncrasies. The engine as built by Jess Myers (Belted Air Power) and
Johnny at Northwest Aero have proven to be very good choices for
auto-conversions.

Matt Whiting wrote:

wrote:

On 2 Jul 2004 17:47:44 -0700, (pacplyer) wrote:


Trashed? I just read Bill's post you provided. It resonated with
honesty and reasonableness.


I never claimed it didn't. I was just surprised to hear Bill praising
the airplane recently when I remembered him describing all the
problems he said it had when he'd been the test pilot.


Where does he say the reduction unit kept failing
other than the one bad belt?


Well actually he has aluded to several bad belts that failed but that
really isn't the point. He challenged me in the usual foul mouthed
BWB way to prove that he had at any time said anything negative about
Meyers airplane and/or the OMABP. Luckily for me, a generous
anonymous lurker found the information and made it available.

I wasn't trying to discredit the guys who built the airplane, it's
just not my style and I'm pretty sure everyone here in this group
knows that. What Bill originally stated back in 1997 has apparently
become "Inopperative". Because today he seems to think it's a fine
machine.

That's good because it's better to have Bill's support than to have
him against you. For all I know, the OMABP never even knew of Bill's
comments, not everyone knows about this group after all, so perhaps no
harm was done. But Bill did ask me to find the comment and repost it
for all to see. With the help of my anonymous benefactor, I've done
as he requested.

Corky Scott



If I was building an RV, I'd certainly give this option a serious look.
I do wish there was more data available on this engine as compared to
a similar Lycoming. If you read through the web site, you can find most
of the information such as weight, power, torque, etc, however, it isn't
in a nice tabular comparison that would be much more useful. I also
didn't see fuel consumption anywhere, but may have just missed it. It
would also be nice to see W&B info comparing the Lyc to the Chevy.

I've got a 4.3L Vortec in my 1994 Chevy pickup and it has been pretty
reliable now for 10 years and 85,000 miles. The only serious problem I
had with the engine was at about the 5,200 mile point. It dropped a
cylinder on my way to work one morning and was making an awful clatter.
I called the dealer as it was still under warranty and I figured
they'd want to tow it in to avoid further damage. They asked if I could
drive it. I said "yes", but had to run it hard to keep it up to
cruising speed. They said to just drive it in then. They found that
the intake valve pushrod had come apart and welded itself to the rocker
arm. I don't recall the details now, but I believe it was an aluminum
pushrod and had a steel ball spin welded to it. The ball came loose and
the aluminum pushrod fused itself to the rocker arm. They replaced
that, changed the oil in the engine and it has run fine since. The only
other problems I've had are oil leaks. Simply can't stop this engine
from leaking somewhere. I've replaced the main seals (front and rear),
oil filter adapter gasket, intake manifold gasket, and one other gasket
that I can't remember now.

The engine has never left me stranded so I think I'd be OK flying behind
one.

Matt


--
Bruce A. Frank, Editor "Ford 3.8/4.2L Engine and V-6 STOL
Homebuilt Aircraft Newsletter"
| Publishing interesting material|
| on all aspects of alternative |
| engines and homebuilt aircraft.|
*------------------------------**----*
\(-o-)/ AIRCRAFT PROJECTS CO.
\___/ Manufacturing parts & pieces
/ \ for homebuilt aircraft,
0 0 TIG welding

While trying to find the time to finish mine.