alternative engines, now Hemi

[Gary Derian]

OK, you guys convinced me.  My thought was that during the few milliseconds
of flame travel, less heat would be absorbed by the head and piston.  It
stands to reason that the amount of heat actually absorbed during this
period is very small.  Once the flame front has passed and the power stroke
begins, the threat of detonation has passed.

Gary Derian <gderian at oh.verio.com>

> At 10:05 PM 5/21/99 -0400, Gary Derian wrote:
> >Engine research using ceramics is headed toward an adiabatic engine.
That
> >is one which needs no cooling system.  This keeps the fire hotter during
the
> >power stroke since no heat is absorbed by a cooling system.  I would
think
> >this would actually increase propensity for detonation.
>
> My *guess* is it's the other way around, at least in a 4 stroke. The
> inside of the combustion chamber will be hotter right after the burn
> than it would be in a metal engine, due to the lower heat capacity
> and higher thermal resistance. But by the same token, the incoming
> charge will be able to cool those same surfaces more than if they
> had a low thermal resistance path to a big mass of hot, high heat
> capacity metal.
>
> I know a couple of people have reported reduced detonation with some
> of the diy coatings. Has anyone had the opposite result?
>
>    Chris C.