question about 4v heads
08-27-2008, 08:12 AM
#1
2nd Gear Member
Thread Starter
Join Date: Jul 2005
Location:
Posts: 348
question about 4v heads
does any know what the cfm is of teh 4v heads cause im thinking about doing a 4 valve swap but if i can just do a set of aftermaket 2v head that flow just as well i dont see the point thanks for any help
08-27-2008, 11:35 AM
#2
3rd Gear Member
Join Date: May 2008
Location: NH
Posts: 574
Yeah, to me it makes sense to go with a set of partiot heads. That way you can still use the same intake manifold, valvecovers and timing covers and that stuff. You might want to think about getting a set of used pi heads and get some cams at the same time. I just did a pi upgrade and did headers at the same time. I'm kinda regreting not doing cams while i was at it, but i didn't really have the cash flow at the time. good luck
08-27-2008, 11:40 PM
#5
Banned
Join Date: May 2007
Location:
Posts: 4,064
I believe 4v heads flow around 330 stock, the problem is nobody will list what their bench settings are, but anyway they are still about 50 cfm more than stage 3 ported 3v heads.. stock, and then when you port 4v heads you get another 30 cfm or so - this is off the top of my head a long time ago
08-27-2008, 11:48 PM
#6
3rd Gear Member
Join Date: Mar 2007
Location: Ca
Posts: 891
(Going off memory here but I have a good memory regarding SHM flow bench numbers)03/04 cobra heads flow 233 cfm @ .500 and 96-98 heads flow 231 @ .500 Ported 2v heads at .600 lift flow about the same as stock 4v heads while ported 96-98 4v heads can flow 300+ . PS I have some ported 4v heads laying around pm me if itnterested.
08-27-2008, 11:48 PM
#7
3rd Gear Member
Join Date: Aug 2008
Location: Michigan
Posts: 578
I believe 4v heads flow around 330 stock, the problem is nobody will list what their bench settings are, but anyway they are still about 50 cfm more than stage 3 ported 3v heads.. stock, and then when you port 4v heads you get another 30 cfm or so - this is off the top of my head a long time ago
.. I saw a link a few years ago that listed them all side by side on the same machine - stock through ported.. you guys have any links?
08-27-2008, 11:53 PM
#10
3rd Gear Member
Join Date: Aug 2008
Location: Michigan
Posts: 578