steve65 said:
step one
verify TDC
http://garage.grumpysperformance.com/index.php?threads/finding-top-dead-center.967/
STEP
two VERIFY your ignition timing and function
http://garage.grumpysperformance.com/index.php?threads/verifying-your-real-advance-curve.4683/
http://garage.grumpysperformance.com/index.php?threads/timing-lights.875/
http://garage.grumpysperformance.com/index.php?threads/timing-tabs-and-indicators.1015/
http://garage.grumpysperformance.co...ouble-shooting-rebuilding-hei-ignitions.2798/
step three
never assume the problem
is limited too ignition issues UNTIL YOU PROVE IT AND CORRECT IT
http://garage.grumpysperformance.co...conductive-grease-for-ignition-modules.10748/
http://garage.grumpysperformance.com/index.php?threads/how-altenators-work.355/
http://garage.grumpysperformance.com/index.php?threads/reading-plugs.5428/
http://garage.grumpysperformance.com/index.php?threads/burning-out-distributor-modules.3797/
http://garage.grumpysperformance.com/index.php?threads/distributor-gear-wear.1701/#post-5252
http://garage.grumpysperformance.co...stalling-the-intake-manifold-distributor.464/
you might also have a fuel delivery
(fuel pump, or fuel filter)
or valve train
worn cam lobe,
cam timing gear,
weak or broken valve springs,
a restrictive catalytic converter,
restrictive exhaust,
related issue,
a bad alternator bad spark plugs or a dozen other issues that NEED to be checked!
NEVER GUESS CHECK EVERYTHING.
if your ignition advance is too rapid or goes past about 40 degrees its likely to cause detonation as too much cylinder pressure builds before the piston passes TDC, not after where it can do work as designed
your torque is basically related to how effectively you build and use cylinder pressure and your engines displacement.
as long as most of the cylinder pressure builds after the crank throw passes TDC, the pressure in the cylinder is used to push the piston down on the power stroke and make power, any pressure built before the crank rotation reaches TDC reduces power as it resists rotation, keep in mind at low rpms it takes about 30-50 thousands of a second to burn a cylinder of f/a mix, as the rpms increase the time required to burn the compressed mix decreases due to several factors like squish and turbulence, but at low rpms you don,t need a great deal of ignition advance because at 1000rpm your only getting 500 power strokes per minute per cylinder, or about 8 power strokes every second, so 6-8 degrees advance allows plenty of time to build pressure above the piston, as it reaches and passes TDC, and have most of that pressure build after tdc in crank rotation.
BUT if you increase the rpms to 3000rpm and youve cut the available burn time into less than a third, so ignition needs to occur sooner in the rotation, thus the need to advance the ignition point in relation to piston movement compressing the fuel/air mix, but as rpms continue to increase the flame pattern advance due to constantly being compressed faster and more violently, decreases the need for further increased ignition advance at some point, usually at about 3200rpm, where your ignitions usually fully advanced
ONCE YOU PLOT THE ADVANCE CURVE IT WILL LOOK SIMILAR TO THIS
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