About heat and cooling. In the 1/2A world, one of the excuses for poor throttling was that these small engines run too cool to allow for good throttling. The Norvel .049 and the .06 have substantially more cooling fin area than the ubiquitous, Cox engines, which CAN be difficult to throttle. As such, the Norvels run far cooler than the Cox and as has been shown, small Norvels can be made to throttle as well as any of the best .40s

I've machined down the fins of Norvels for winter flying out of fear of running too cool. No need, because I've also run stock Norvels in sub-zero temps with absolutely no problems, power and throttling are on par with summer time performance. Naturally, you just have to back out the needle some.

Once again, the versatility of Norvel engines come shining through.