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Old 01-16-2012, 03:31 PM
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Mein Auto: 2004 330Ci ZHP 3 pedals
Originally Posted by smolck View Post
My brother in law's race car has a cam with a .780 lift, the useable power band is 4000-8500 rpm. And no, it would not make a good street motor.

On a separate note, I have seen modest gains from porting and polishing heads on pushrod V8's and unshrouding the valves etc. Anyone ever do this to the already good flowing E46 heads?

I wonder if my local salvage would let me test on one and then bolt it to a festers car. I don't want to mess with my ZHP like that so if I can pull it off, who wants to have the head swap done?
Porting & polishing is like part of a good 3-course order to really appreciate it, you also need the other two components, which in this case would be improving the intake, combined with a set of headers, maybe with race cats, and a top-notch free-flow exhaust. This may be oversimplifying things a bit, but I find it a good alalogy to think of your engine as a big air order to get more power from it, you need to get more air INTO it, get the additional air processed efficiently (the port & polish job), then get the air OUT efficiently....i.e., "increased volumetric efficiency"....
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