Patrick wrote:

Hi Paul,

    Would appriciate it if anyone can tell me how to get hold off
Richard
Finch the author of
"converting auto engines for experimental aircraft"I have only got a
phone
number in Santa Barbara just rings, I assume therefore snail mail
address is
not valid either.

Thank's
Patrick Stepelberg
South Africa

I don't have his address.
I just read his article on motor mounts in one of the magazine lately.
I forgot which magazine it was. I was amazed. This guy has been around
for years writing bad books on alternative engine installations.

The guy is welder and not an engineer. Some of his advice is downright
dangerous.
He gives the impression that any automotive engine would make a good
aircraft engine.
Nothing could be further from the truth.  With cast iron rods and
crankshafts
prevalent in modern automotive engines most are hand grenades waiting
to explode when high continuos HP aircraft service is required. The
Chevy Corvette V8
is a prime example. Probably the lowest duty (low work load) engine
on the road today. No mention of the importance of power to weight
ratio.

In his article he implied that you could some how determine the stress
on
a motor mount by building a plastic pipe replica. Again a totally false
impression. The only thing you can determine with a model is if you
have enough tubes and if the tubes are in the right place for a rigid
space frame structure. In other word; are the load input points
supported
by three or more tubes and are all bays triangulated probably?

No mention of steel tube buckling and actual load calculations.
Buckling calculations are critical to the successful design of a motor
mount.

Paul Lamar

Some of his welding "advice" is pure crap too.  He is a self appointed
expert who has been blessed by the FAA.  His statements are read and
believed by beginners seeking information they can depend upon.  A real
problem...     Jerry

Here is the article. July 2003 Sport Aviation. Quote "And [yep the sentence
started with this word.] the American Welding Society Engineering Department
has long recommended this method as a quick and reliable way to analyze the 
stress and design of welded structures including engine mounts."

No way. No real engineer is going to make a statement like that.

 http://www.aws.org/

It is necessary to go through the numbers to calculate the stress.
If you check the ACRE NL web site I walk you through a rather
simple procedure for doing so providing you keep the design simple.
Once you know the loads on the compression members you
must check for buckling by using this chart.

Paul Lamar

 
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