Spark & rpm
#2
You can't just ask the question that easily for a simple answer.
Spark advance is 'totally' program derived from RPM, throttle opening, ambient temperature, load and EGR operation at any given time.
It's not like a distributor that has flying advance weights, springs, vacuum assist and driven from the camshaft for forced advance with limited auto adjust.
.
What are the conditions you see your reading besides just RPM?
At 750 rpm, the normal fully 'hot' idle is around 10 to 13 degrees.
Cold start could be 20 degrees +/-.
.
At 4500 rpm it would be quite a bit for good amount of throttle applied that could be in any gear, any road speed.
44 degrees could be to much under most conditions and result is spark ping/knock.
The only time that much advance should be seen in Over Drive at very light throttle between 45 and 55 mph when EGR is in operation.
A special set of conditions are present to cause that much advance with EGR.
This RPM would be in the 1400 to 1800 RPM range +/- with a 3.55 rear gear ratio at very light throttle..
Give more detail on how you measure spark advance and the conditions they occur.
Good luck.
Spark advance is 'totally' program derived from RPM, throttle opening, ambient temperature, load and EGR operation at any given time.
It's not like a distributor that has flying advance weights, springs, vacuum assist and driven from the camshaft for forced advance with limited auto adjust.
.
What are the conditions you see your reading besides just RPM?
At 750 rpm, the normal fully 'hot' idle is around 10 to 13 degrees.
Cold start could be 20 degrees +/-.
.
At 4500 rpm it would be quite a bit for good amount of throttle applied that could be in any gear, any road speed.
44 degrees could be to much under most conditions and result is spark ping/knock.
The only time that much advance should be seen in Over Drive at very light throttle between 45 and 55 mph when EGR is in operation.
A special set of conditions are present to cause that much advance with EGR.
This RPM would be in the 1400 to 1800 RPM range +/- with a 3.55 rear gear ratio at very light throttle..
Give more detail on how you measure spark advance and the conditions they occur.
Good luck.
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Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
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02-24-2004 11:27 PM