rockfoot

Three things. First, I am kinda new to the forum and have been following along somewhat. I am a merchant seaman and there are months at a time that I do not read the forum. My grandson has a 2000 Mustang GT with the 4.6 V8. He bought it with a rod knockin' and his dad bought a re-man. I guess it is going to be my job to swap or at least supervise the swap of these engines. In reading along and searching for my particular (current) problem, the mention of PI and NPI in the manifold section comes up often.. Please... what does PI and NPI stand for? I can see and appreciate the difference in the manifolds but nobody ever says what NPI and PI stand for.
The problem I have now is that during the removal of the intake, while removing the heater hose from the manifold, the spout broke off. The material that was left inside the hose looked very, very thin. Does this plastic/composite stuff wear out? Is this common? Is there a fix or do I go buy a new manifold? NPI or PI? I am guessing that NPI is stock and I think that is what I have. After reading some of the threads, I am taking it that the PI is the preferred manifold. For what reason? Thanks for any and all comments or assistance. RB

MaxxRPM

PI = Performance Improvement
NPI = Non Performance Improvement

96-98 GT 4.6 is referred to as NPI motors (215-225hp).
99-04 GT 4.6 is referred to as PI motors (260hp).

Your grandson's GT should have the PI motor.
The PI motors have much better heads,cams, and intake manifold......(hence the 260hp verses 215-225hp).

rockfoot

Thanks... Went out and looked at the engine some more. Starting to learn a little more about what is going on. This thing has 8 individual coils and no spark plug wires to speak of... I guess that is good. Is the PI manifold the same one that they use on the DOHC's? The manifold on my grandson's engine has the deeper chamber that fits down in the "lifter valley"..not sure what that space is called now..without lifters...lol.... so I guess that would be a PI. Are the after market (elderbrock,etc) manifolds a pain in the butt or are they a direct boltup, no hassel swap?
Again, if anybody knows; can the manifold heater pipe that is broken off.. be fixed? Seems that if it is a common problem, somebody would have developed a fix by now...ie. bore it, thread it and screw in a piece of pipe (cvpc?) with epoxy..?? just sayin'...

MaxxRPM

No sir, the DOHC is a different ball game......They never came out in GTs (well, not till 2011 anyway...lol), they only came in Cobras and Mach 1s.

That plastic heater hose nipple is a common problem for the PI intakes. No real cure for it other than a new intake. There are some aftermarket intakes but not many. The factory intakes are good performers but I think the plastic just gets brittle over time.

FrostByte

Trick Flow has a kick *** intake for the 4.6 2v.

Stevo86

Whatever you do do not go to a local parts store to get the replacement. All they sell is the Dorman intake which is a piece of junk with a poor gasket design. You can order a brand new factory intake from americanmuscle.com for the same price as the cheap one. Around $240.

rockfoot

One more quick question that you guys on this thread might could answer... before I attempt it... .>Is it normal to pull the standard transmission with the engine, like in the old days, or pull the transmission first or leave it in place..? Haynes doesn't address the standard transmission engine, only the automatic...

Stevo86

I left my tranny in the car when I swapped my motor out. All the bolts are easily accessible and with the intake off the top two that are the PITA are right there hanging out. Just leave the cross member bolts in and once you pull the motor the bell housing will rest nicely on the sway bar. Just stick a jack under it when you remove and re-install.

Another handy trick is to take off the starter solenoid. It makes it easy to get to the top started bolt without a huge extension through the front end and lots of cursing.

rockfoot

Yea.. I thought I had the top bolt out of the starter..but.. there was one more...what a pain!!! The book doesn't tell you that there are 3 bolts in the starter...lol. With a universal and an extended extension we got it out... not sure how or if it is going back in though!! I think I am going to leave the xmission on the motor when I pull it... I will let you know more tomorrow evening. It always makes a mess. I think I will bag the end of the xmission. They make little plastic thingys to put in the end but I don't have one. I used to pull chevy engines regularly and I had an old yolk that I could stick in the end while I was pulling the engine/xmission... I don't do this very often anymore. Thanks for everybodys input..RB