which head for the 4.6L?

91LX2Bfast · 07-25-2003, 05:53 AM

Here's what a set of Renegade's heads flowed for a friends street car, and Jim could have gone a bit more, but he wanted to keep the port ratio at around 70% for a good split.
intake:
.100"-68
.200"-120
.300"-166
.400"-190
.500"-208
.600"-220

exhaust:
.100"-95
.200"-142
.300"-161
.400"-170
.500"-172
.600"-178

Something to remember..absolute peak is nothing for comparing flow numbers..
Add up the values from .100-.600,and them add up the same values from the head that is being compared-and see who has more total "area under the curve". Also remember..you spend alot more time at .300-.400 lift than you do at .600 from just the physical aspects of camshaft lobes.

I am not trying to start a war here or anything. I guess I expressed myself wrong in the first couple of posts. I just don't think that the PI's are the all high and mighty for street cars when you get into porting. From what I have seen is the NPI's can be made to work very well, and for less total cost. Sure, out of the box, there's no comparison, PI hands down.

Thread Tools
Show Printable Version Email this Page
Display Modes	Rate This Thread
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode	Rate This Thread:

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
head light problem	crazyi	Windsor Power	5	12-17-2003 06:37 PM
DOHC 4.6L head	mynameisjohn	Modular Madness	4	04-25-2003 05:05 PM
what head ?	faststang90	Windsor Power	3	09-08-2002 07:17 PM
Anyone ever used the ultra seal 5751 silicor head gaskets yet?	11secondGT	Windsor Power	0	08-06-2002 10:23 PM
Will the 5.0 become obsolete	vetteeatr	Blue Oval Lounge	36	07-11-2002 08:39 PM

07-25-2003, 05:53 AM	#1
91LX2Bfast Registered Member Join Date: Dec 1999 Location: Warrington, PA Posts: 694	Here's what a set of Renegade's heads flowed for a friends street car, and Jim could have gone a bit more, but he wanted to keep the port ratio at around 70% for a good split. intake: .100"-68 .200"-120 .300"-166 .400"-190 .500"-208 .600"-220 exhaust: .100"-95 .200"-142 .300"-161 .400"-170 .500"-172 .600"-178 Something to remember..absolute peak is nothing for comparing flow numbers.. Add up the values from .100-.600,and them add up the same values from the head that is being compared-and see who has more total "area under the curve". Also remember..you spend alot more time at .300-.400 lift than you do at .600 from just the physical aspects of camshaft lobes. I am not trying to start a war here or anything. I guess I expressed myself wrong in the first couple of posts. I just don't think that the PI's are the all high and mighty for street cars when you get into porting. From what I have seen is the NPI's can be made to work very well, and for less total cost. Sure, out of the box, there's no comparison, PI hands down.