You are correct sir, though there are a number of things that contribute to
engine knock (combustion chamber design, timing, carburation, cam, head
porting, outside temp, engine temp, intake air charge temp, etc.). I
figured that I would probably get some knock, but wanted to see for sure
before I invested time in alternatives. Race gas is expensive, at least
here in Washington State (I hear that AV gas is only about $2.25 a gallon in
Florida... Road trip?), and what do I do when I go to Shasta (octane boost
is a waste of money and not that effective). That is why I am strongly
considering water/methanol injection. Octane is nothing more that the
fuel's ability to resist pre-ignition (detonation... bad stuff, i.e. fuel
exploding without a spark event), or uncontrolled ignition (knocking caused
by the air/fuel charge not burning in a controlled manner). A fine mist or
fog of water or water and methanol will work the same way to control the
fuel burn. There are new (and very high dollar systems) available (such as
Aquamist) that will allow very high boost levels (like 25-30lbs) in
turbo-charged engines, sometime even without an intercooler. A high
compression engine does not need that degree of sophistication, but the idea
is the same. Water injection has been around a long time, but todays
computer controlled, knock sensing cars are designed to control knocking in
a different manner, usually by automatically backing off the timing and
richening the air/fuel mix slightly. Computers and fuel injection can do
that... I can't! Still, computers are not always the answer. A friend told
me today of another friend that just put a hole in the piston of one of his
turbo-charged cars when he changed to an "upgraded" computer. Guess it was
not as upgraded as he thought (or maybe he did not take into account other
things that needed to be "upgraded")!!!
Greg "no holes please" Burrows
Marko Lahtinen wrote:
> Greg
>
> Nice to hear you are on the road again. Its a great
> feel to be able to take the car out after a long
> spell.
>
> On the knocking, I always thought it was a matter of
> using higher octane fuel than 92 especially given your
> very high compression ratio.
>
> Anyone?
>
> Marko
> 64 1500 with R16
>
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