hey grumpy!
What range should cranking compression be on a pump-gas street motor? It seems to me that after you have done your research, calculated your static compression ratio, picked your cam, degreed it, and have everything buttoned up that a cranking compression test is about the only way to see where you really are. I've heard of advancing the cam until you reach the maximum cranking compression reading. Any thoughts? What is the limit for a 93 octane motor? 180 lbs? Is cranking compression a valid test? What about procedure? Any thoughts on this? I know what I've seen on my motors, but I'm wondering if maybe I cheated myself out of a few horses on the last one.
THIS INFO MIGHT HELP, keep in mind that the cylinder head temp,the rate of heat absorbsion to the coolant, the octane of the fuel, quench,distance, air temp, ignition advance an cam timing will effect the results, what your talking about is ballancing max cylinder pressure , you can generate by playing with the static compression and the cam timing (DYNAMIC COMPRESSION) to generate maximum torque while keeping in mind the need to stay out of the detonation range that too much compression for the heat of the engine and octane ranges of the fuel will allow, so you don,t need to compensate by doing things like backing off on the ignition advance curve or adding octane boosters to the fuel.
viewtopic.php?f=53&t=726&p=2302&hilit=quench#p2302
viewtopic.php?f=55&t=613&p=1379&hilit=booster#p1379
viewtopic.php?f=52&t=727
http://victorylibrary.com/mopar/cam-tech-c.htm
http://victorylibrary.com/mopar/piston_position-c.htm
http://www.pontiacstreetperformance.com ... ssion.html
http://www.motionsoftware.com/glossary.htm
http://kb-silvolite.com/calc.php?action=comp2
viewtopic.php?f=57&t=149
viewtopic.php?f=44&t=937&p=1922&hilit=+detonation#p1922
viewtopic.php?f=53&t=110&p=1672&hilit=+detonation#p1672
viewtopic.php?f=55&t=2718&p=7057#p7057
viewtopic.php?f=50&t=383&p=1637&hilit=+detonation#p1637
What range should cranking compression be on a pump-gas street motor? It seems to me that after you have done your research, calculated your static compression ratio, picked your cam, degreed it, and have everything buttoned up that a cranking compression test is about the only way to see where you really are. I've heard of advancing the cam until you reach the maximum cranking compression reading. Any thoughts? What is the limit for a 93 octane motor? 180 lbs? Is cranking compression a valid test? What about procedure? Any thoughts on this? I know what I've seen on my motors, but I'm wondering if maybe I cheated myself out of a few horses on the last one.
THIS INFO MIGHT HELP, keep in mind that the cylinder head temp,the rate of heat absorbsion to the coolant, the octane of the fuel, quench,distance, air temp, ignition advance an cam timing will effect the results, what your talking about is ballancing max cylinder pressure , you can generate by playing with the static compression and the cam timing (DYNAMIC COMPRESSION) to generate maximum torque while keeping in mind the need to stay out of the detonation range that too much compression for the heat of the engine and octane ranges of the fuel will allow, so you don,t need to compensate by doing things like backing off on the ignition advance curve or adding octane boosters to the fuel.
viewtopic.php?f=53&t=726&p=2302&hilit=quench#p2302
viewtopic.php?f=55&t=613&p=1379&hilit=booster#p1379
viewtopic.php?f=52&t=727
http://victorylibrary.com/mopar/cam-tech-c.htm
http://victorylibrary.com/mopar/piston_position-c.htm
http://www.pontiacstreetperformance.com ... ssion.html
http://www.motionsoftware.com/glossary.htm
http://kb-silvolite.com/calc.php?action=comp2
viewtopic.php?f=57&t=149
viewtopic.php?f=44&t=937&p=1922&hilit=+detonation#p1922
viewtopic.php?f=53&t=110&p=1672&hilit=+detonation#p1672
viewtopic.php?f=55&t=2718&p=7057#p7057
viewtopic.php?f=50&t=383&p=1637&hilit=+detonation#p1637