>With 92 octane fuel, double dose of CD-2 lead substitute, and ignition
>timing of 4 degrees BTDC, my dieseling and engine knock are better, but
>still present. What octane boosters or antiknock/dieseling additives have
>people tried that seemed to work best? A friend suggested I try Marvel
>Mystery oil.
>Bill Lewis
Marvel really shouldnt work as an anti-knock additive, as its really just a
light oil. Could actually make the problem worse as the added carbon could
create the very hot spots that contribute to the pinging in the first place.
As to octane additive, the stuff you buy in a small can, does work but
the sheer amount of volume of the stuff needed to do any REAL improvement
makes
that scenario economically unsound.
Look at the can of magic stuff, does it say what the amount of octane will
be
when you are done mixing it in your gas?
No...
Because then you would know that you need gallons, and not ounces to get
that magic "104" octane improvment.
Many engines run on the hairy edge of what 92 octane can do for then engine.
These engines "at least the newer ones" also have knock sensors that will
automatically adjust ignition timing to the fuel that they are given.
These engines might do well with the added half point actane boost you get,
but in general, its just a way to seperate you from your money.
Still need higher octane fuel?
1) Buy racing fuel at $3 to $6 a gallon its not cheap.
2) Buy lots of the magic octane boost (I mean gallons).
3) Get a chemical additive that reduces the volatility of available
gasoline.
FWIW Dieseling is usually NOT an octane problem on engines not full of
carbon.
Dieseling is usually cured by adjusting the idle for a lower RPM, and a
reasonably
lean (ever so slightly rich) idle mixture.
70s carburetted cars used a solenoid that acted as a throttle stop.
When ignition was turned off, the throttle plates were closed even more than
the idle position, and engine usually doesnt run on.
Jarrid Gross
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