porting RPM heads
Melting Slicks
Joined: Dec 2000
Posts: 2,041
Likes: 0
From: Wichita, KS
I bought my Edelbrock RPM heads bare so I could install reduced stem diameter valves and clean up the ports. The shop that did the work cleaned up some minor casting ridges and did some work in the bowl areas behind the valves.
I was impressed with the quality of the heads as they came out of the box and doubt that you would notice a seat of the pants change in performance but it's nice to know that they have been optimized.
I was impressed with the quality of the heads as they came out of the box and doubt that you would notice a seat of the pants change in performance but it's nice to know that they have been optimized.
Race Director
Joined: Mar 1999
Posts: 10,258
Likes: 1
From: Calif.
Originally Posted by panchop
Do you think it's worth the money to have a set of Edelbrock RPM heads ported for a 327 street car? I have a little time to kill waiting for my tranny soooo..
About all you'll need to do is match the ports to the intake gasket and "clean up" the intakes about an inch down the hole. Combustion chambers and exhaust ports are another story. Gently round off all the sharp edges, if any, in the chambers and then use progresvely finer abrasives until the chambers have an almost mirrored finish. Give the same treatment to the exhaust ports all the way from the chamber to the exit.
Pay special attention the the short turn radius in both the intakes and exhaust. Stick your finger in there and feel them. If they're nice and smooth and round (like most aftermarket heads are) you're OK. Smooth them off if the turn is abrupt.
And that's about all a DIY-er can do. Anything over and above that gets into the terriroty of the "head porter" and involves no small measure of Black Magic.
also blend into valve seat 
