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--
"If you can't excel with talent, triumph with effort."
-- Dave Weinbaum in National Enquirer
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Date: Sun, 27 Sep 1998 17:51:54 -0700
From: Joe Curry <spitlist@gte.net>
Organization: Curry Enterprises
To: Tomislav Marincic <TomAndKate@compuserve.com>
Subject: Re: Pinging vs CR
References: <199809272039_MC2-5AD3-9A13@compuserve.com>
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Tomislav Marincic wrote:
>
> Joe,
>
> RE:"we were not discussing changes to the combustion chamber but
> rather shaving the head..."
>
> The two are one and the same, no?
Not at all. You are not changing the shape of the chamber, only
reducing the upper limit of it. This reduces the final area in which
the gas has to compress, but does not change the relationship of the
valves and spark plugs to the compressed gasses. Therefore one
eventually reaches a point where any more shaving will cause pinging for
a fixed octane rating.
Changing the pistons to domed ones does affect the shape of the
combustion chamber, so if properly designed, one could expect that
custom pistons could raise the compression ratio to a higher degree
using the same head before the pinging would start.
But as this is all hypothetical, you never really know where that limit
is reached or how much one method delivers over the other. So with that
in mind, I go back to my other emotion (that of not wanting to remove
any more metal that absolutely necessary) Since we don't have the
computer models that are used in designing modern engines, all we can
hope to do is look at the competition books prepared by others in the
past and our own experiences (good and bad) to arrive at what we
consider the best for our needs. Then hope that we have made the
correct decision.
That is why the exchange of ideas here on this list is so valuable. We
can look at viewpoints and experiences of others to arrive at reasonable
conclusions for our own needs. In essence we become a "Collective
intelligence" And as we all know, "Resistance is Futile".
Regards,
Joe
>
> Best Regards,
>
> Tom Marincic
--
"If you can't excel with talent, triumph with effort."
-- Dave Weinbaum in National Enquirer
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