NPI and PI engine questions??

sn95jones

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Took this earlier was under about 65% acceleration on a slight incline, I had started letting off at about 4k
[video=youtube;ZIhno3fdouc]http://www.youtube.com/watch?v=ZIhno3fdouc&feature=plcp[/video]
 

clark98gt

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The only thing I would like to throw in to this conversation is, if you are going to put a PI intake on npi heads, you need to use PI intake gaskets not npi gaskets. I have done the swap and researched it quite a bit. You put the PI gaskets on along with a small dab of rtv to seal the water ports that dont match up exactly with the gaskets. I am running this setup on my 98 gt right now with no leaks at all.
 

FrankenStang

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you do know there are alumi cross over npi mani'salso rite? check how deep it goes into the valley...also if the 2nd coolant sensor is factory then its npi NO pi's have a stock 2nd coolant sensor on it unless its a aftermarket Dorman intake manifold...
 

clark98gt

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Very good Frank. My 98 came stock with an aluminum cross over npi intake. If no one believes us I will gladly sell it to them lol. It is just sitting in my barn taking up space.
 

FrankenStang

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just did a Pi mani swap today...i also found that the heater hose has a spot on it on the back of the block for a coolant sensor...SOOOOO you DONOT need to tap the manifold, just extend the 2 sensor wires......and Yes use PI gaskets on NPI heads for the PI manifold swap.....ullealso need to RTv the front passengers side coolant port to match the gasket as well as the rear drivers side...ullelose lowned a bit but above 2.5k rpm's ulle feel it breath and pull harder, ulle need the pi cams to make up the down low and the heads to set it off...and if you do do a pi head swap...atleast port the heads while out, if even to even out the runners it adds a nice little free easy bump in HP...
 

clark98gt

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That is what I am running right now. PI intake, PI cams, bbk cold air intake, bbk h pipe, flowmaster cat-back, sct tuner, and last but not least custom busted t45 4 speed.
 

sn95jones

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Very good Frank. My 98 came stock with an aluminum cross over npi intake. If no one believes us I will gladly sell it to them lol. It is just sitting in my barn taking up space.
That's funny because my '98 didn't. Had to replace it myself.
 

clark98gt

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I dont know. Mine is a late 98 if that makes any difference? It says Ford on it and everything.
 

sn95jones

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I dont know. Mine is a late 98 if that makes any difference? It says Ford on it and everything.
Whoever owned it before you most likely either bought a factory replacement or had the dealership do it.
Ford does have the replacement intake with the aluminum crossover
 

clark98gt

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Being that it is a 98 I wouldnt be surprised if it is in fact the stock intake. Ford did some weird stuff with the 98 mustangs compared to the earlier years. It was like the test dummy for some of the new edge stuff. Just look at the bastard returnless looking, non returnless fuel system.
 

sn95jones

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I've not ever heard any story where a 98 GT came from the factory with aluminum crossover intake.

The odds of even getting a GT that was lucky enough to get it would be like 1-100,000.
I am 99% certain your's was replaced at one point.
 

clark98gt

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Well that is your opinion. It doesnt really matter either way since no one wants a npi intake, aluminum crossover or not.
 

turion94

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20413821-2E64-436D-8A9A-05594835C7D2-544-0000004D0388E9BC.jpg


Here is a cool pic of a 4.6 next to a 5.0. What a difference!

4.6 < 5.0 (IMO) ;)

-Will
 

MustangChris

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lol. i <3 that pic.

the 4.6 longblock is indeed bigger than a 5.0. but who cares?

The SOHC 4.6 is still fairly easy to work on inside the engine bay.... the DOHC is a much more difficult beast, but still do-able. 1000 HP ready heads. yea, lets complain about THAT..... pffft. lol.

5.0 timing equipment > 4.6 timing equipment. that's for sure.
 
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i have look at my intake and it dont look like its ever been changed. and it has the alumin cross over. mine is a 98.
 

sn95jones

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i have look at my intake and it dont look like its ever been changed. and it has the alumin cross over. mine is a 98.
The intake could be replaced and you would never notice, when I did mine myself once I finished you couldn't ever tell it had been torn apart. Here is a pic of it after it was done.
317969_10151233474199741_1607728036_n.jpg
 

Redford

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*sigh*

ALL 1999 - 2004 Mustang GT had the PI set up and no the valve covers wont work the heads are different. The difference in power is about 60hp the PI set up is called PI because its callrd Performance Improved. The heads are different, cams, and intake are all different.
The vibration at 2500rpms could be a bad harmonic balancer or you could have bad motor mounts

This is wrong. You CAN use valve covers interchangeably, as long as they're Romeo heads. I'm pretty sure the Romeo PI heads were 01-04. 99-00 GTs are all Windsor heads, or so I've read. My PI heads were Romeo heads, so I could reuse my NPI valve covers (which have the oil fill on the driver side). All PI engines have the oil fill on the passenger side, but Romeo-head PI engines have 11 bolts on the valve covers, which makes them interchangeable with all NPI valve covers (which are also Romeo). It's the Windsor PI valve covers that you're thinking of (12/13 bolts I believe).
 
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i counted mine and its 11 bolts and its a 98 gt. i have a set of bbk valve covers that have 13 bolts. and they say sohc on them. which i cant use. so they need to go.
 

Redford

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All NPI valve covers will have 11 bolts, so that's right. You just got 99-00 covers meant for Windsor heads. Should be pretty easy to get some that work since the majority of GTs will have 11 bolts.
 

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