View Single Post
  #25  
Old 01-16-2012, 03:32 PM
Fast Bob's Avatar
Fast Bob Fast Bob is online now
Keeping it surreal
Location: Here, there, everywhere....
 
Join Date: Jun 2004
Posts: 34,790
Mein Auto: 2004 330Ci ZHP 3 pedals
Quote:
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 dinner....in 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 pump....in 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"....(Hemis are the best head design for this, which we all benefit from)
__________________
The road goes ever onward....
(R.I.P. Jever)

*Please support the Wounded Warrior Project*

When faced with choosing between two evils, always go with the one you`ve never tried before....
Reply With Quote