Heat generated is a function of the calories burned. If you run "cooler"
you're generating less power. Doesn't make much sense to me. Then
again, I'm just an old biker.
What your friend might have meant is that the heat is disipated over a
larger portion of the cylinder wall. Since the flame propagates slower
the piston is lower in the cylinder exposing more of the cylinder wall to
the heat generated. This way the cooling system has a better chance of
picking up the extra heat to carry it away. That's why the HEAD will run
cooler--it doesn't have to do all the heat exchanger work!
In short, while you will generate more heat with higher octane fuel it
will be easier for your cooling system to dispose of it. Net result-a
cooler engine.
On Sun, 5 Nov 1995 FUSIONDES@aol.com wrote:
> On the subject of octane for MG's, I had a wise old biker once tell me (in
> the '60s) to always use the high octane fuel in my motorcyle. It
> burned...cooler. I understand the explosion is slower, and longer than the
> high temp flash from lower octane gas (thus the "ping" reduction).
> I'm sure it was true on my motorcyles (they ran cooler), and while I use
> cheap low-octane in my disposable Detroit Iron, I have always used high test
> in my B's. I think it's better for them (less heat and stress from the
> explosions, and I only buy 10 gallons once a month or two anyway). Any
> comments from any wise old MGers?
>
> Dave Tietz
> '70 B roadster
> '74 B-GT
> '90 Chrysler & '94 Lumina Van
>
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