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Old 12-17-2011, 06:50 PM
454C10 454C10 is offline
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yes, torque and horsepower goes up with more compression. But be careful, BBC don't tolerate compression as well as a sbc.

FYI, valve overlap doesn't effect cylinder pressure, as the engine isn't trying to make cylinder pressure during this part of the 4 stroke cycle. The intake closing point is what effects dynamic cylinder pressure (what you would measure on a compressing gage). And a "longer duration cam" will tend to have later intake closing point, the extra overlap is often wrongly accused of reduce pressure as more overlap typically accompanies longer duration cams.

Actually extra overlap can be used to increase torque (as in circle track engines). For example...Two cams with the same duration, but one has a tighter LSA (more overlap), will close the intake sooner in the compression stroke and develop more torque. Advancing the cam will have a similar effect.
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