NPI Head Milling

Gearbanger 101 said:

Take a quick trip over to www.tccoa.com. Plenty of MN12 T-Bird/Cougar guys over there are making good use out of the Non-PI castings that most Mustangers give away for next to nothing. Nearly all of them swear by the porting done by Renagade Racing in Michigan. You can contact Jim directly here at fastford@peoplepc.com and he'll answer any questions as far as flow and cost that you might have.

The pictures and flow figures for his heads, speak for themselves....






These were a set done for Johnny Langton over at the tccoa. He went for the whole shooting match with these ones with full portwork with throat enlargement (not just a CNC job),milling of the head surface to insure a clean face,comp valve job,high-lift springs,titanium retainers/locks,teardown/cleanup. These particular heads flowed The flow over 200cfm at .500" lift,and 220ish cfm at .600" lift on the intake and just over 190cfm on the exhaust side. That beind said, they ran about $1,500, but you get what you pay for.

Another member 96 GoldBird also had a set done there that weren't quite as heavily worked and his turned out as follows....









You can can different levels of head work done of which flow and cost are directly related. These are average flow figures for your basic Renagade ported NPI head.

PNP NPI
Lift..............Intake................Exhaust
.100"--------- 67----------------62
.200"---------120----------------97
.300----------165---------------137
.400----------193---------------152
.500----------210---------------164
.600----------222---------------175

For reference sake, this is what a set of PI, Ported PI’s and stock FRPP castings flow for comparison.

PI

Lift..............Intake................Exhaust
.100"--------- N/A----------------N/A
.200"---------115----------------103
.300----------148----------------128
.400----------166----------------143
.500----------175----------------156
.600---------- N/A--------------- N/A

Ported PI
Lift..............Intake................Exhaust
.100"--------- 64----------------52
.200"---------116----------------94
.300----------162---------------130
.400----------192---------------160
.500----------213---------------178
.600----------217---------------185

FRPP

Lift..............Intake................Exhaust
.100"--------- N/A----------------N/A
.200"---------142----------------100
.300----------181----------------131
.400----------196----------------150
.500----------213----------------150
.600---------- N/A--------------- N/A



Had one of my heads not be screwed when I bought my car, this is probably the route I would have chose. But as it sits, I got a set of PI castings at a fabulous deal and couldn't pass them up. I have no doubt though, that a properly ported set of NPI heads would performe every bit as well as my ported PI heads. As it sits, your intake is a perfect match to the Non-PI castings, so this is just one more alternative for you to take, over the FRPP castings.

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