Quoting Kate Triplett <ad_ablurr@xxxxxxxxxxxxxxxxxxxxx>:
> OK, you fellows with the electrical engineering degress have it all over me
> for pure knowledge base - and I quote:
Kate, if you refer to me, I am a hummble mechanical engineer. But I do know a
few things about electrons. Its Dick B. who is all over those electrons.
> feedback/controlling (my assumption) wire back to distibutor, so it's
> genuinely possible that there is a speed/interval sensing capability inherent
> in the system.
This "feedback" could have been a knock sensor, like modern cars. This sensor
bolts on the block or intake manifold and senses high frequency vibrations
which are likely induced by engine knock or pinging and retards the timing
momentarily until the pinging stops. Then, after a while, advances back to
normal again until it encounters knock again, in which case it retards, again.
All/most modern cars have these devices. That's why you will never hear a
(well functioning) modern car pinging, even if you use lower octane fuel than
recommended (but of course, the retarded timing results in some loss in
efficiency as opposed to the higher fuel that would not ping).
> changes made as much difference as they did. The '77 pickup was in fine
> condition, though, and other than it's affinity for high octane, I had no
> problems with it - would love to know why spark improvement would result in
> less demand for the hi-test gas.
Either the above, or its overall spark advance was reduced. You could have
achieved the same result if you had simply retarded the total timing, but at a
loss of efficiency. Its possible that the Jacobs deal had overall more
suitable advance curve, or held the timing more advanced maintaining good
efficiency except for the few ocasions where it would try to ping.
D^2
>
> I had been seriously considering swapping out Lucille's stock points
> distributor for an electronic one, until reading this latest thread. I never
> have been fond of setting up a set of points! If you don't get it JUST RIGHT,
> the whole thing suffers. I have never had problems with the stock Chrysler
> e-ignitions, something I can't say for other makers.
>
> I did do a Pertronix conversion on a 1962 Buick Electra, back in about 1975
> or 76, which ran trouble free and really improved the car's performance and
> economy. Hadn't heard of them failing before - would be very interested to
> know if the failures were on old installations?
>
> Kate Justet Triplett
> Kate's Custom Gunleather
> Monroe, Washington
> Proud mother of a soldier
> and owner of "Lucille" 1968 Crown
>
>
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