>I am running somewhere between 9 and 9.5 on my TR6. Why? Because it was a
>bit less than 10:1. Just a shoot from the hip. I have no trouble with
>pre-ignition on 89 octane gas but I do get the occasional diesel situation.
>
>Dave
I'll be picky here...
The condition caused by high compression and low octane fuel is detonation,
not pre-ignition.
Also called pinging, knocking, or pinking, detonation is an exploding of the
fuel/air mixture instead of a burning of the fuel/air mixture. It occurs
when the mixture reaches it's critical temperature and pressure. This can be
caused by using fuel with too low an octane rating, advanced timing,
pre-ignition, or lean mixture. Maybe other things.
Pre-ignition is the igniting of the fuel/air mixture by something other than
the spark plug (a hot spot in the cylinder) before the plug can ignite it.
It can cause detonation for the same reason as advanced timing; the fuel
burns longer and gets to its critical pressure and temperature.
Picky mode off.
John
=== This list supported in part by The Vintage Triumph Register
=== http://www.vtr.org
|