Pond Skipper

Grinding the fins down has been done before back in the day the 1/2A speed pan guys would do this to their engines and shoehorn them in smaller cowls to reduce drag. High speed planes cool better as there is much more air circulation than a sport plane and these parts are cheap to replace and repeat.

The Lil Speedy jams out good on a 4.2 x 2 but can not swing the 4.2 x 4 without running rich rpm drops under 18k.
The mods will make the plane go ballistic with the 4.2 x 4 for about 3 mins.

Mr Cox

Sure, with a proper cowl and high enough speed you might get enough cooling.
Surely the landing gear, for instance, would be the first thing to remove for a lower weight and less drag...?

Pond Skipper

Yes very true. I keep the legs on to protect the low wing as the field is rough with some small rocks, the spring steel has been bent many times already saving the covering on the wings / balsa dings and front end cracks. The .049 is an easy fix for more speed without slapping a electric motor on the nose.

I'm looking forward to bench testing the engine with a throttle sleeve which will aid in heat dispersion / will use a fan while testing to mimic some additional inflight cooling.
If the reed valve can do 21k on the ground I may mount it on the plane to see what it can do in the air. I read some folks have exceeded 23k at which time even a mylar reed has trouble keeping up.