BCGARDNER@aol.com wrote:

Paul,

The latest (May) Sport Aviation has an article on page 38 that chronicles a
guy's Velocity with a GM 4.3 liter V-6 in it. Aside from the fact that he
chose the wrong engine ;^) I was wondering if you or other list members had
comments on his engineering of the adaptation, including his P-51 inspired
cooling system.

Barry Gardner
Wheaton, IL

We had pictures of that cooling system on
the ACRE NL site for months. I obviously felt he did it almost right.
Could be better however. So I took them off the web page.
Cosmetically (and that is all the EAA  really cares about) 
it looks great.

For that airplane I think he would be better off with two rads
in the cowling useing "arm-pit" or belly NACA scoops. 
Particularly with a much narrower rotary engine.

For haveing the claimed 220 HP at 4500 RPM that airplane is slow.
800 FPM to 1000 FPM for a 220 HP airplane hauling only 55 gallons
of fuel and a variable pitch prop and only a 2250 pound gross 
weight is nothing to write home about. On top of that it has
retractable landing gear. They did not mention the top speed.
Maybe Neil know's Tim England and can tell us the top speed.

Heck my old tech C182 will do better than that at 230 HP and 3100
pound gross hauling 85 gallons of gas and four people. 
 
Part of it could be the cooling drag. Part could be the crappy 
prop and part could be a slightly optimistic HP rateing for that 
engine at only 4500 RPM. (Consider the exhaust and intake manifolds 
and the two barrel Holly carb).

BTW note the aircraft vacuume pump with the special belt drive
bearing block and the flat Singer sewing machine belt (Yes) driving
the pump off the prop shaft. When I talked to Tim at Oskosh he
said it was not working well :-) He may have changed it to a
V belt or cog belt by now.

duct1.jpg
 
Paul Lamar
 
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