Head Questions

[Tom Wesenberg]

I agree with George.
I see the higher compression head only adding to the bearing load during starting the engine or driving with a lead foot, or having the spark too far advanced. Lets say it takes 23 horsepower to move the car down the road at a steady 45 MPH. Since the higher compression head is more efficient, then less air and gas is admitted during suction, so the compression pressure should be about the same with a lower compression head and a throttle opened more.

This is why I like the idea of a higher compression head, counterweights for the life of the bearings, and a higher gear to reduce engine speed.

[40 Deluxe]

Originally Posted by Anteek29

Curious:

With a 5.5 head, what would the compression reading be?
With a 6.0 head, what would the compression reading be?

A similar question: How high is 'up'? Answer: It depends! Depends on cranking speed; on altitude; on engine temperature; on engine condition (amount of leakage past the rings); on amount of carbon in the combustion chamber, if any; on camshaft timing (how long valves are open); and on how accurate your gauge is.