Octane question

[Dave Gilles]

.004” squish on a piston port induction 27-31cc engine. Tight.

yeah it wasnt on purpose. A friend put the wrong gasket on an engine I ported.

 

[Mark Anderson]

What signs of detonation are you seeing? Any pics?

 

[Dave Gilles]

looks like sand blasting. just like a nitro engine.

 

[DON MAHER]

Well I

how sure are you? I get detonation starting at .006" squish with 87. It gets severe at .004" I really don't want to destroy this new promodded cylinder.

Hi Dave,

To answer your question, I have not had any sign of detonation using Coleman fuel with the squish as low as.004” !
I normally run.006”-.007”. The downside is the cost of “camp”fuel ,which is about 3 times more than 87 gasoline! The upside is not having to worry about diaframs going bad, and no gas stink!