gatt

Sushidot wrote:

> As far as I can explain it, P.I. happens on the ignition stroke but
> before the stroke is completed and is caused by a carbon spot or a
> plug fouling.
>
> Detonation occurs due to pressure in the Cylinder being high or the
> engine/cyl temps are high and cause an explosion..

Yeah. Detonation -is- the explosion.

Pre-ignition is simply the fuel-air mixture igniting prematurely, ie,
before the spark plug fires. Combustion as such is otherwise relatively
even.

Detonation is when it explosived spontaneously or instantaneously and
can happen after the spark. Of the two, detonation is the most destructive.

-c