Re: Simple IC engine
The simplest engine is probably going to be a 2 stroke. Crankshaft and piston ports do all the valving, Model airplane fuel and glow plug are cost effective and all you need to get it started is a 1.5 Volt battery. Carb can be a fixed carb with a simple spraybar. Check ou the .60 2-stroke plans I uploaded a while back.
Oh - and another plus - no gears.
KF2QD, South Texas
HF MiniMill, HF 7x10
Hardinge UM, Enco 12x36