Given the recent release of Cosworth's new cylinder head, I thought it might be interesting to make a rough comparison of head flow data. I used Cosworth's data for the stock head, their head, and inserted Buschur's data from the percentage improvements at various lifts as claimed by Buschur. I could not insert AMS' data because I don't have it.

This is intended for purposes of discussion only, so don't take this as gospel. It's just a thumbnail sketch that is only as accurate as the data used.

 

The obvious question.... why use anything over a .50 lift cam on a stock head?

 

AFAIK, there are no EVO cams with that much (0.5") lift.

Actually, it appears flow begins to drop off on both the Int and Exh sides around .30" lift (7.6mm)on a stock head.

 

right.... I'm not aware of any cams that have that lift either.

The point I was trying to make was the cams that advertise "high lift", like Revolver, have no benefit on a stock head. My bad, should have been more specific. A 10.xx mm lift cam should be plenty good for a stock head.

 

Good post. I have always figured that high lift cams wouldn't have a real benefit on a stock head.