Quote:
Originally Posted by Tom Vaught
Cylinder pressure is related to trapped volume in the combustion chamber prior to ignition as well as other variables. A poor camshaft choice can have a effect on a engine with the wrong compression ratio for today's fuel octane at the pump.
Tom V.
|
As Tom says, there are other variables affecting knock and ping, but dynamic compression is determined by the cam chosen. Overlap between closure of the exhaust valve and opening of the intake allows cylinder pressure to bleed off. How much depends on how much overlap. Dynamic compression is the important factor affecting an engines tendency to knock or ping. Static, or calculated compression AFFECTS dynamic compression, but that number is not what the engine "sees".