Re: alfa-digest V7 #604

[Formeister@domain.elided]

In a message dated 4/1/99 2:53:09 AM Eastern Standard Time, owner-alfa-
digest@domain.elided writes:

> Date: Wed, 31 Mar 1999 21:39:06 -0800
>  From: "JMazlumian" <jmazl@domain.elided>
>  Subject: RE: 98 Octane?
>  
>  Dave answered:
>  >  Octane is not a measure of energy, but of resistance to burning.
>  >  The reason
>  > that performance street or racing engines often use higher octane
>  > fuel is to
>  > provide resistance to detonation.  This allows you to run higher
>  > compression
>  > ratios or more timing without blowing holes in your pistons.
>  >
>  ++++++++++++++++++++
>  Octane rating is only one of the fuel qualities.  I know that higher octane
>  alone will not do much unless there is a turbo or supercharger.  I
mentioned
>  it for ID purposes.  However, fuels have other qualities such as Burning
>  Speed, (the speed at which a fuel releases its energy.  If the fuel is
still
>  burning after peak cylinder pressure, it's a waste, and perhaps
>  counterproductive).  Energy Value, an expression of the potential energy in
>  the fuel, measured in BTU's per pound.  Cooling Effect, related to the heat
>  of vaporization, the higher, the better, but granted, more inportant in 2
>  stroke engines than in 4 stroke.
>  So I thought that these higher quality racing fuels might be of some
>  benefit.  Since I have no racing experience I thought I ask.  By hte way I
>  failed to mention they cost about 3 times more!
>  
>  Thanks to Dave for his response.
>  
>  Jorge, who wishes his Milano was as fast as an M3
>  (no I'm not buying an M3, I like the Milano better)
>  Redlands, CA
>  

Higher octane gas actually has less BTU's/pound than regular gas.  This
requires more fuel for the same HP.

My .02

Frank Formeister

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