The engine is now fitted with a exhaust manifold and muffler. The manifold and muffler have a 2.5 x the volume of the engine displacement. In the damper is a tube pattern with several large holes, surrounded by damper wool.

This was a long test run without extra cooling, the temperature outside was cold and would test how it runs when the cylinder head and cylinder get quit hot.
Engine running on 102 octane ethanol free fuel.

Stationary run 17502000 rpm ; Max speed without load 4500 rpm ish.


Model Engine Maker forum where the build has been shown:
https://www.modelenginemaker.com/inde...