flyin51

iTrader: (1)

I need to make a move on a new engine for my old 4.6. Really interested in the PI swap/ideas. I have searched all over the net and have found tons of info. Problem is every other thing I read contradicts the next!! I WOULD LOVE TO TALK TO SOMEONE WHO DID THIS DIRECTLY, either to their truck or a buddy. Any help is beyond greatly appreciated!

jprevat

iTrader: (1)

Carcrazygts2 on here has a pi swapped 5.4. If you have an auto trans get a 5.4 torque converter and use the bigger v8. Iirc all you need for a pi swap is the heads, intake, and tune.

If you see his posts on the forum then you can bet money what he says is on point.

Carcrazygts2

Everything will work. I've been running a PI swapped 5.4 for years. What is it you need help with?

white89gt

I think he's thinking of putting a PI engine in a 97 and I take it he wants to know if all of the sensors will swap over, etc.

flyin51

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I'm wanting to replace my 4.6. I think I can get the non PI reman w/PI heads, and my mechanic says the intake will be no problem. Questions:

Any particular year for the heads or intake? Far as I can tell I need heads from an 01 up 4.6.?

Anything else need to be done? I read bout another temp sensor?

Will I need to run higher octane due to the higher compression? Will I need to get a tuner/custom tunes?

I have researched myself nuts. Any answers will be truly appreciated!!

Carcrazygts2

You wont have to do anything with the extra coolant temp sensor, I am not using it at all. I am only using the Factory CHT. Heads can be from a 99+ Mustang GT, 99-03 5.4 F150 or a 01+ 4.6 F150. You will need a newer intake manifold (01+ 4.6 F150). But you will only need the intake it self. You wlll need to reuse you throttle body elbow. Also get a set of manifold from a PI truck. The ports are larger and are slightly reangled to flow better. You will have to open up the bolt holes on the 2 bolt flanges. You would also need the newer EGR tube as well.

A custom tune would be ideal. You can get away with 87 as long as the tuner doesnt push the timing to far. Compression ratio will be close 10.2:1. My experience is slightly different because the 5.4 but I also have cams and alot more compression.

I would upgrade the fuel pump, along with upgrading to 24# injectors. We are talking about close to 100 hp at the crank difference.

white89gt

Sorry to butt in, but I've heard this figure before of a 100hp difference. Is this because of the tune? Just wondering because IIRC, the PI headed trucks were only rated at 15hp more from the factory. Or is there something better about the older pistons making more compression?

Just wondering for future reference.

flyin51

iTrader: (1)

Wow...alright. So I need to drill out the manifold flanges for some reason? The upgraded fuel pump/bigger injectors is def needed?? If so do you have any recommendations there? As far as tunes go I have the Edge, but it was reprogrammed with custom tunes by Power Hungry Performance. Long time ago so who would be best to get a programmer from now? Dumb question but what do you mean EGR tube? I know sensors but never heard EGR tube

Seriously I greatly appreciate you answerin all these Q's!!

Carcrazygts2

I've seen what they do on a dyno. In the truck its more like 75hp/100tq at the crank. On a mustang is it close to 80rwhp. The NPI pistons are completely flat tops with no valve reliefs. The NPI heads have a much larger combustion chamber. The PI pistons have a dished piston from the factory. When you put them together on average its close to 1.3 full points of compression. Ive seen several stock NPI 4.6's and on average they are around the 140hp to the wheels mark( a little higher for 2wd's). Ive seen tuned PI swapped 4.6's with other bolt on ans supporting mods dyno 240-250 through the factory 4r70 slush box.

A bone stock truck with just a tune and PI heads would be around the 210-220 mark.

Carcrazygts2

I would pickup a SCT handheld unit. Either MPT or 5 Star tuning. The EGR tube is the metal pipe that goes from the exhaust manifold to the EGR Valve on the driverside of the enigne. If you decide not to upgrade to the newer PI exhaust manifolds you have no reason to drill out the 2 bolt flanges. I personally would. They are larger and freer flowing.

If your only doing the PI head swap and nothing else then fuel injectors/pump arent really needed. But they will be around a 85-90% duty cycle. Also by upgrading to newer injectors you will get injectors that have a better spray pattern and atomize the fuel better. When I first did mine I had detonation issues with factory injectors. Even tho they were NOS replacement.

I will get you the part numbers for a 155lph pump, and the injectors that will be plug and play in case you choose to upgrade them. I personally would just due to age.