porting npi heads

[98COBRA281]

what if i just put pi cams in my npi heads, will that be a decent hp improvment

 

[CobraRed_96_GT]

Porting and Polishing is more than just cfm, maybe you should google that and find out.

god, this board increases in hostility everyday. I said power numbers were the same of better earlier. I gave the CFM cuz that's something i could find. I'm done here anyways

 

[Stan Weiss]

If he says he doesn't have that much money, he's not going to go FI. Porting and polishing removes material from the combustion chamber, therefore, increasing the size of the CC and decreasing compression ratio. So in losing CR, he would lose hp in that way, although gaining power through increased flow. So if he installs PI heads, they will flow better in comparison to the lift of the camshaft he is going to use.

PI heads were designed to flow better through the mid range of the lift, so why would he want a ported NPI that flows better cfm at the top of the lift when he's going to more than likely going to get a PI camshaft that's not even going to give that much lift.

Porting and Polishing is more than just cfm, maybe you should google that and find out. Joe Blow down the street is not going to know how to port NPIs to outflow ported PI heads, or even out power them. Just because ported NPIs might out flow ported PI heads, that doesn't mean they are going to make more power.

The flow numbers you gave above don't compare anything. Are you comparing exhaust or intake? A PI head can be ported and polished to flow up to 245 cfm intake. Tell us what your comparing

So what don't you enlighten us as to which has the better velocity, or Discharge Coefficient, or CFM flow per Square Inch of valve area. What is your criteria for comparing heads?

 

[Smokeurhonda]

Look everybody here is giving valueble information about these setups. Personally I didn't know all this about these heads so thanks guys. But as it was mentioned before, let's not get hostile, it's no fun for anybody.

 

[98COBRA281]

what about putting pi cams in my motor is there an improvement?

 

[blubullett]

Yeah but it probably wouldnt be worth the labor unless you are porting your heads at the same time. Too much work. Maybe 10 hp?

 

[Green&GoldGT]

Most of the improvement you will see with a PI swap is with camshafts and intake. I would suggest better camshafts, but PI camshafts are cheap. If you want a CR like you listed then go with used PI heads. Port them yourself if thats what you choose. Or better yet save up and something like a stage 1 cam and ported heads.

As for the previous replies, I was trying to emphasize how there is no right answer. For example, there are some people that go with a high compression with boost, not people who don't know anything but alot of engine experts. I just hate when people give advice when there are more factors to consider. People think that everything they read on stangnet or any other board is true. Don't just post a bunch of junk and say your right. Get your facts straight before you post, and I'm not calling anyone out. I'm not trying to be "hostile," I'm trying to make the site better by having better advice for fellow stangnetters

 

[98COBRA281]

ya i would like to bring up my compression, bucause boost is out of the question for now bucause of money, and it does have almost 101k on it if i ever got boost i will rebuild the whole motor, but if pi cams are only 10hp i dont think its worth it

 

[forum155pl]

well for a whole PI swap your only going to get 40 or so HP out of it.. if you already have the intake thats the biggest part of it.. the cams is the next part.. the big reason why PI heads give you more power is because of the higher compression..

if you put PI cams in your car and you already have the intake you will be doing a big thing to your motor, porting will give you ALOT less HP then the PI cam swap will.. your best bet is to buy some used PI cams and toss them in there..

 

[98COBRA281]

thanks forum155pl

I will have to look for some pi cams now, is ther any thing else i will need like cam gears? and i have to remove the whole front cover right?

 

[DropTopPony]

I would personally put a set of Renegade ported NPI's up against anyones ported PI's in quality,velocity.flow etc anyday but they are not cheap.

If you are on a tight budget you can go the PI cams/Intake route or do like i did and shop around for the complete PI swap used. I found the Heads/Cams for $350 shipped and the intake for $100. It then was about $300 for all the needed gaskets,bolts,dipstick tube,hoses etc from Randy at Liberty Ford in Md. For under $800 i had a nice easy upgrade over stock.

Shop around and you will find deals. Check the classifieds here and on corral.net and sn95forums.com

 

[98COBRA281]

yeah for now i am just going to do the cams i already have the pi intake, whats the diffenece between the npi and pi cams like duration and lift?

 

[5spd GT]

Click on the link in my signature for PI Headswap information.

It has a parts checklist, procedure help, and random information about cam spec differences, head differences, and other ideas.

By the way, if anyone knows of anyone with a PI intake that is cracked or broken, let me know. I want to purchase it.

 

[Ryan441]

i swaped in a cam in my garage in about 3 hours, i didnt take the front of the motor off or anything just the valve cover. its fairly simple once youve got it apart

 

[98COBRA281]

i belive i have romeo heads (11 bolt) do the cams have to be out of a romeo too?

 

[rugster]

no