why pi heads ? are there better ones?
- Thread starter nakednipple
- Start date
Roush97
Founding Member
nakednipple said:
indeed they are stock 99+ heads. they is only one other option and that is the SVO heads from Ford racing. they cost a small fortune compared to the pi heads thats why you dont see alot of them around. however these svo heads do flow a decent amount more than the pi heads so if you have the cash at the time you're buying heads they are something to look into.
Roush97
Founding Member
jamez1502 said:
i've never heard of Jeser however if they do have a kit it consists of pi or the svo heads. they are the only two available for our cars.
Roush97
Founding Member
nakednipple said:
not necessarily. there are about a hundred different porting choices out there. from VT to Modular Powerhouse to fox lake to Houston performance. there is a port job out there to fit your cars needs.
just stock and svo. you can also put on 4.6/5.4L truck heads and DOHC, but some more work is required.
StratGT
Founding Member
Soomething to remember is that NPI heads flow quite well compared to PI heads. Ported NPI outflow stock PI heads. You have NPI heads that could use a good porting. The real flow advantage is from the intake.
Do a search on this website and see the results from just changing the intake, the results may surprise you.
Do a search on this website and see the results from just changing the intake, the results may surprise you.
StratGT said:
and if you do more research on this site you will notice it is cheaper to upgrade to PI then to port out the NPI. and in a true comparison the ported
NPI's don't come close to ported PI's.
Yes and no. Maybe if you were buying all used stuff, but you can have a set of NPI heads ported and dressed in PI cams for a lot less than the cost of buying a set of new PI's. Not only that, but if someone were running forced induction and didn't want to swap out the stock internals to keep the compression ratio down, they'd be better off having the NPI's ported. Yeah, I'll agree that if you're wanting to make more power still, a set of ported PI's will outflow a set of ported NPI's, but ported NPI's along with forced induction is capable of easily sustaining over 400rwhp. And that seems to be a pretty comfortable level for the stock internals anyway. When you start getting past that, you're getting into a whole other cost factor anyway.tomustang said:
StratGT
Founding Member
tomustang said:
I said porting NPI heads which are already on his car, meaning he doesn't have to buy another set of heads will out perform PI heads. Purchasing ported PI heads + you'll needs cams + a intake ain't freaking cheap.
StratGT said:
ok so you find a shop to port heads, porting done correctly 500+ and way more where i have seen. then dissasemble the heads, intake, wiring yada yada.. I've seen PI heads new for $299 a piece, intake $219 lowest. and if you want to go blown cometic gaskets are the best route it will drop your CR. or if you don't have enough to upgrade to a s/c nitrous work well with higher compression. ie: LS1+nitrous=
So tell me which part of that all makes the PI heads better?tomustang said:ok so you find a shop to port heads, porting done correctly 500+ and way more where i have seen. then dissasemble the heads, intake, wiring yada yada.. I've seen PI heads new for $299 a piece, intake $219 lowest. and if you want to go blown cometic gaskets are the best route it will drop your CR. or if you don't have enough to upgrade to a s/c nitrous work well with higher compression. ie: LS1+nitrous=
You still have to disassemble the intake, wiring yadda yadda to install the PI's. So you're $600.00-$800.00 for a set of new PI's and about the same for a professional port job for the NPI's and a set of stock PI cams and adaptor plates (if you so choose to use them) for the PI intake. After all is said and done, you're still running about the same price and the ported NPI's are still moving more air than the stock PI's. And removing swirl dams are great for making power (later on….not with a stock head) and dropping compression, but horrible for fuel economy and low speed drivability. I'm not saying that PI's aren't great head, but I'm saying that the NPI's are the doorstops that most Mustang owners think they are. The ’96-’98 guys are junking them right and left and practically giving them away on Ebay and the guys in the early T-Bird/Cougar and Crown Vic’s are buying them up for peanuts and laughing all the way to the bank. I personally would have used my NPI’s over the PI’s I bought had the A) not been fcuked up because the last owner ceased one of the cams up in the head, B because I needed to move the amount of air only a set of ported PI’s could move and C) because I got a fan-friggin-tabulous deal on them 
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