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911st 911st is offline
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Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
Bottom line, it is easier to make big HP by moving a motors area of efficient operation to higher rpm than trying to increase efficiencies at lower rpm enough to make a significant difference.

For example, a motor making 350 ft lbs that is built to move the HP peak from 5500 to 6200 goes from 378hp to 416hp. Such a change requires no more power per stroke, just doing it at a higher rpm with changes in cam timing and ancillary systems of sufficient size to support doing so (ports, IC size, turbo...).

To get 416hp at 5500rpm it would take 404 ft lbs of TQ. That requires increasing the power per stroke by 15%.

Just for fun, I believe the following is a best of the best example of a low rpm torque cam on a very well built CIS motor.

Old 11-23-2009, 05:16 PM
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