Greetings, earthmen...okay, make that earthpeople.
I've been wondering about some of the side-effects of changing
ignition timing. For example, years ago I remember noting with one
of my Fiats that when a shop had set the timing incorrectly the
result was a change in how the engine sounded (besides the
traditional "pinking"). The sound was a significant increase in the
deep hum, especially at lower rpm, or to put it another way, an
increase in the low freqeuncy components of the growl induced when
I'd push the loud pedal. My recollection is that this happened when
the timing was advanced too far, but I don't trust my memory. Is
this an expected behavior of a Triumph 6? With the stock or non-
stock cams?
A related question is whether earlier timing would be expected to
give a cleaner exhaust. My thoughts say yes because longer burn
times mean less hydrocarbons. But then, I have no instrumentation to
test such a hypothesis.
The reason for the questions is that I'm still trying to settle on
the optimal ignition timing for the GT6. I hear no obvious pinking
(amidst all the other racket the car makes!). Don't really know if
the cams are stock. I've been keeping it when idling at about 4 deg
earlier than the designated static timing, but cognitively that seems
early. Given the carbs it has (a pair of H4S's), I (believe I) can't
easily hook up the idle retard and set it to spec
Anyone want to comment?
Tanks!
--
Jim Muller
jimmuller@pop.rcn.com
'80 Spitfire, '70 GT6+
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