im doing the pi head swap on my 97 gt. i am going to port the heads. would it be worth it to do the swap and porting w/ out a new cam? what kind of power will it make w/ out cam and w/ cam? how hard is it to port the heads yourself? i no a guy that will cnc port them for 200$
Ported PI Heads vs. Ported Non-PI heads is hardly a difference to brag about
Port the PI heads w/PI cams= chances are you may have to go with after market cams being you won't make as good results with the stock PI cams.
not true. Many of the old school guys ran ported PI head cars with stock cams before aftermarket cams were available, and many were in the mid to low 12's na with higher trap speeds than just PI swapped cars. Porting the heads does not require you to use aftermarket cams, to see gains over stock pi heads, but it does help
I can also counter that. Many were running low 12's with NPI heads as well. I never said you had to use after market cams. However, I believe I said you may not make as good results with a PI Cam than an after market. To take advantage of the increase ability to push air and get the most hp and best results it would be wise to use after market cams over PI ones.
There are several ported NPI engines making just as much if not more power with PI cams and PI Intake. Some have gotten 250-260 rwhp with them. I am simply stating that you can get away with just the PI Cams and PI Intake and port the NPI heads and still make more HP than if you just went with a PI headswap.
I can also counter that. Many were running low 12's with NPI heads as well. I never said you had to use after market cams. However, I believe I said you may not make as good results with a PI Cam than an after market. To take advantage of the increase ability to push air and get the most hp and best results it would be wise to use after market cams over PI ones.
There are several ported NPI engines making just as much if not more power with PI cams and PI Intake. Some have gotten 250-260 rwhp with them. I am simply stating that you can get away with just the PI Cams and PI Intake and port the NPI heads and still make more HP than if you just went with a PI headswap.
I wouldn't pay 300+ for 5-10 hp just all for a bump in c/r. I rather spend that money I saved and port the heads and get twice as much hp.I agree with most of what you are saying but you fail to mention the power gained by going from 8.5 c/r to about 10.5:1 with the PI head swap. I have to run 91-93 octane and I know a higher compression means more power.
NaI agree with ya on that. I just thought you meant you needed to run aftermarket cams if you had the heads ported
The heads are not a restriction as much as you people make them out to be. The Cams and Intake are. After porting, the NPI's are as equal, if not better N/A than PI's. With a little work and reshaping of the intake ports, they will flow much better than the PI counterparts, since the PI's don’t have as much meat in them to port. The exhaust ports on the PI heads is much better stock than the NPI's, but with dilligent work, NPI’s can flow almost as well as ported PI's. the NPi's have a quench pad that allow for a faster and hotter burn in the chambers, which we all know is key to N/A power success.
Port the PI heads w/PI cams= chances are you may have to go with after market cams being you won't make as good results with the stock PI cams.
You need to reread what I posted. I have been there and done that with the heads. Set them side by side and had a look. Did a couple PI Headswaps myself.
I am talking about both being ported, there is hardly a difference in flow.
so what you guys are saying is instead of paying $400 for the pi heads and aftermarket cam plus w/e else i need to do the swap, i would be better off just porting the npi heads w/ a aftermarket cam? pi intake also?
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