Re: Twin Sparks, superchargers etc

[bearbvd@domain.elided (Greg Hermann)]

At 8:35 AM 8/24/02, Norm Riffle wrote:
>Keith Walker wrote:
>
>>
>> Subject: Twin Sparks, superchargers etc
>>
>> >>    And could the TS rods be similarly used to lower the compression
>> ratio of a "nord" w/ TS head?<<
>>
>> Not sure, but consider that lowering the compression in such a crude
>> way will leave you with a fairly awful combustion chamber shape. It
>> may also land up being worse for preignition due to the lack of
>> squish than the stock higher compression engine
>
>Please bear with me, I'm WAY beyond what i know much about, but...
>    assuming identically shaped pistons
>    and identical (combined) length of piston and rod
>wouldn't the (static) combustion shape also be identical?

On a very superficial level, yes, but from a functional standpoint, not at
all. The squish clearance has _almost_everything_ to do with the amount of
turbulence in the chamber when the spark lights the fire. The tighter the
squish clearance, the more active the turbulence, and the faster the burn
rate. The faster the burn rate, the greater the power, the greater the
efficiency, and the greater the detonation resistance.

>    On a different tack, I am talking about two different factory rod
>lengths. If the factory did it for the 8vTS, I'd have to believe it was an
>improvement. Assuming the same crank, why wouldn't this be true?

They must have played with either the deck height, or the compression
height of the pistons at the same time.

Greg
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