> if you take a tach that was in a 4 cylinder vehicle and put it in a
> vehicle with a 6 cylinder engine, the reading will be wrong. Or
> visa-versa. It also doesn't matter if the tach is electric or
> mechanical. One revolution is one revolution.
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Oops - while one revolution is one revoloution, one timing pulse divided by
the number of cylinders is definatly different - I would say this indicates
that a mechanicaly driven tach would be interchangable with any engine
(given the same spedo calibration and would make sense from a manufacturing
standpoint) but an electric wil be 'cylinder' specific (calibrated for the
number of pulses it's going to see per rev) - so I think it does matter -
if you look at any triumph electronic tach you will see very tiny printing
stating 4cyl, 6cyl or 8cyl. you don't see this on mechanical tach's
Barry Schwartz
Bschwartz@encad.com (work)
Bschwart@pacbell.net (home)
(San Diego)
70' Spitfire (under-going major surgery) , 72'-V6 Spitfire (daily driver)
70'GT6+
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