I am not fan of automotive piston engines for aircraft use
as the design and materials used are not up to the
continuous power required by an aircraft engine.  They
could fail in a catastrophic fashion without warning.
There is a real reason why only the finest steels and
manufacturing processes are used in real aircraft engines.
For that reason I decline to provide any help.

Read may article on the subject here.
http://www.rotaryeng.net/Rotor-v-Piston.html

Also obtain and read this book.

Sky Ranch Engineering Manual. This book presents an excellent
overview of the problems of aircraft engines. It is 500  pages and a
bargain at only $23. There are many details on the materials and
processes used to build a successful aircraft engine. There is a
very good and exhaustive discussion of destructive  torsional
vibrations and fatigue. The telephone number  to buy this book is
(916) 421 7672. The author is John Schwaner. John is highly thought
of in the experimental aircraft community.

Do not kill the messenger :)

Paul Lamar


It would seem that if Bud did the adaptation of the LS1 to your
airframe that he would be available to provide support to any cooling
issues you might have.  Otherwise, it sounds like you got some custom
parts from him, but are really on your own.

The LS engines are interesting.  They are a far more advanced design
than the previous generation of small block.  They have a lot more
meat in places where V engines seem to need it.  Some people claim to
be getting much improved performance from them as compared to
conventional aircraft engines in terms of fuel burn and performance.
The people with LS powered Seabees are among those that are apparently
succeeding.  I was around an RV-7A that seemed to work OK.  The fellow
that owned it was flying it from my home base in Nampa (S67) over to
Idaho Falls pretty regularly.  Others have not had achieved as much
success.  I don't know whether anyone has enough hours on one to
demonstrate reasonable reliability/durability.

I have the Sky Ranch manual.  I agree that it is excellent.

Matt-


Hi all,
    I am familiar with the typical weaknesses suffered by
automotive engines while operating in an aviation
environment...torsional harmonics, susceptible crankshafts
[and bearings?], and problems relating to continuous high
power output requirements.  However, Trace Engines managed
to get type certification for their automotive conversion
and it is currently used in the Air Tractor 400 series
aircraft.  Can anyone comment on what specific alterations
Trace made to their auto conversions in order to address
these issues?

Gene Kahn

That is the big block Chev based Thunder/Orenda engine.
The cost is over $100,000. Weight 600 pounds
and TBO 1200 hours.

Here is an article on the development.

http://www.rotaryeng.net/DS-smith-art.pdf

Paul Lamar