Which Heads?

[BigJuicy02]

99 EB 4.6L Vin Code "6".

Do I have the PI heads or not? Or is there some indentifier I can look at on the engine to tell?

 

[1998exp330]

i believe if the maniflod is aluminum its an NPI head plastic is PI i might be wrong. i thought ford didnt use the PI head until 2000?

 

[BigJuicy02]

I thought so too but I had read online that some of the 99s had the pi heads. Not sure if that's true. And it's been such a long day I honestly cannot remember which intake I have. I'll check it in the morning. Thanks for the info.

 

[ArtGamer60]

Found this on another forum , it appears from the factory are for the 4.6 , I wouldn't install them on a 5.4 due to the increased stroke ? the cc volume in the combustion chambers will be different and raise compression ratio ( being smaller , not sure though . would have to cc the heads and compare ) as for GP purpose I wouldn't think so - Hope this helps .

How ID PI heads. - Ford Truck Enthusiasts Forums

Found some here , it never hurts to look .

http://www.jegs.com/i/Ford+Racing/3...&cagpspn=pla&gclid=CISWn_rM-LUCFc5AMgodJ3MAcg

 

[toms89]

They started using the "PI" heads sometime in 99 so you may or may not have them. If you can find the part # on the passenger side head above the exhaust manifold there should be a PI stamped near it if its a pi head of course. It may be very difficult to read due to age, corrosion, grime etc...

I do believe what 1998exp330 stated is correct though so it would be the easiest way to tell. And if you have the intake off..... the non-pi heads have round runners. PI heads have square(ish) runners..lol.

You can install pi heads and intake on non pi motors but this will raise compression to around 10 to 1. This is true on both 4.6 & 5.4 blocks due to the difference in combustion chamber sizes between the heads. Ford increased the volume of the dish (cc's) in the pistons on the PI motors to make up for the difference between the heads.

Then there are windsor vs romeo heads and blocks. They are interchangeable but with some minor differences that need to be addressed. The new ford racing PI heads are romeo and have the 8 thread count spark plug holes!!

 

[ArtGamer60]

wonder why they use " squarish ports " ? JK

 

[BigJuicy02]

Ok here is what I have. Windsor engine. Appears to be NPI heads. Aluminum intake. Nothing on the sticker said PI but here is a pic anyways.

 

[ArtGamer60]

I went out to just check and see where the sticker was on mine and it was on the driver's side , I guess it depends , had to look . haha

 

[toms89]

I went out to just check and see where the sticker was on mine and it was on the driver's side , I guess it depends , had to look . haha

That is the engine build code. The heads have part# stamped directly into the heads them self above the exhaust on the right hand side. PI should be stamped near here if they are PI heads. But it may be very difficult if not impossible to read.

I have my original motor in the garage on an engine stand and have difficulty reading it without a bright light. If you can locate it you could run sandpaper or maybe chalk across it to make it visible.

 

[BigJuicy02]

Haven't gotten a chance to get a good look at it yet. Wife's car started acting crazy so I had to put my time in to that, and now there is snow everywhere again. Pretty sure they are NPI heads though.