On Feb 3, 5:03 pm, Rocky wrote:

I am going to use a Suzuki 1300cc (70 hp) with a belt reduction unit.
I had a Samurai for 14 years with this exact engine in it.
On the freeway its almost full throttle and turning 36- 3800 RPM hour
after hour.
Will be the same RPM in the plane at cruise.

I know we might have been over this before, but...

3600 or 3800 RPM on the highway is a LOT different than
3600-3800 in the air. The highway vehicle is using about 25-35% of its
power capacity. Its throttle is maybe half open at the most. Check
yours again and see. In the airplane, 75% is more like it and the
throttle is three-quarters of the way open. The drag on the airplane
in cruise is far larger than the car's because of induced lift and
higher speed, and propellers also waste more energy than tires.
The proof comes in the cooling. The engine that was easy to
cool in the car is much harder to cool in the airplane because the
power output is so much higher and because some intelligent ducting or
baffling is needed to direct air through the rad without creating a
lot more drag.
That said, Raven Redrives have a couple of Suzuki conversions.

Dan