Re: Re: [DML] Fuel Octane

["content22207" <brobertson@xxxx>]

Am shooting 40,000 volts across a .038 plug gap. Trust me, have
complete combustion. Will post pic of plug if you need proof.

89 is not "high" octane. IMHO compensates for all the mixing and
tinkering gas companies do with formulation from time to time, season
to season ("clean burning fuel").

BTW: fire about 10 degrees BTC.

Bill Robertson
#5939

>--- In dmcnews@xxxxxxxxxxxxxxx, "B Benson" <delornut@xxxx> wrote:
> This has been brought up before but to avoid confusion about octane
ratings
> you should understand that octane ratings ARE directly related to the
> combustibility of the fuel. Higher compression in the combustion chamber
> means higher temperatures which require a fuel that ignites and
burns at a
> slower more controlable rate. This would be a high octane fuel. When you
> hear the engine ping or knock it's not the valves rattling, it's the
piston
> and rod bearings reacting to a pre-ignition occurring because the
high temp
> in the combustion chamber has ignited the fuel before the spark plug
fired
> and the piston is still on the up stroke, way too far ahead of the 13
> degrees before top dead center than the DeLorean requires. If you
continue
> to use a high octane slower burning fuel in a car that doesn't
require it
> the slow burn will eventually create carbon deposits in the combustion
> chamber. These deposits take up space and result in raising the
compression
> ratio. In other words your car can, over a period of time, become
dependent
> on high octane fuel.
> 
> Bruce Benson
> vin 6870
> 
> > Much confusion about octane. Measures ability to compress fuel mixture
> > without premature detonation. Does NOT measure "burnability" or any
> > other characteristic.
> I shoot
> > my spark a little closer to TDC than factory spec (high energy
> > ignition), so burn 89 octane to avoid ocassional valve clatter.
> >
> > Bill Robertson
> > #5939