Hi there,
Several people have built 2 stroke radial engines for models and they do generally work very well (assuming they are designed and built properly). They normally use a vane-type supercharger that is driven off the back of the crank. This is then used to pressurise the crankcase and porting is as it would be for any 'normal' 2 stroke. The engine then runs on standard model fuel. There was a commercial attempt at this in the 1990s sometime called the Berger Radial with 7 cylinders, however I'm not sure what ever happened to it.
I have a feeling that the engine may start to get impractical for a model aeroplane if you start trying to have seperate induction on each cylinder along with a 'conventional' bottom-end lubrication system.
As far as diesel goes for model aeroplane engines, again this is not very practical when using direct injection. Almost all 'diesel' (or compression ignition) model engines operate like glow engines (in that they take a fuel/air mixture in), however they rely entirely upon the compression for ignition. ie. they don't have any ignition plug - as you would expect. These engines rely on fairly large quantities of ether in their fuel (normally around 30%). A direct injection diesel model engine was built some time ago (I have a feeling it was in the 1940s), however, it was reported to be exceptionally fiddly to set up and too complex for what it was intended for.
Just a few thoughts....
Keep on going and hopefully you'll have a running engine in the near future!
Regards
Warren
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