Pi Heads?

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Old Dec 6, 2006 | 04:02 PM
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Pi Heads?

i should know this but what does PI stand for as in PI HEADS ON THE 4.6 5.4??
 
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Old Dec 6, 2006 | 05:02 PM
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HI!... I've heard people use other terms for "P.I" but FORD calls them POWER IMPROVED.
 
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Old Dec 6, 2006 | 05:25 PM
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ok cool for some reason im thinking it meant POLICE INTERCEPTOR heads.the ones that are in cruisers.
 
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Old Dec 6, 2006 | 06:14 PM
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penile insert?
 
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Old Dec 6, 2006 | 06:27 PM
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whatever works right?? lol lol
 
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Old Dec 6, 2006 | 06:38 PM
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P. I. - Parched Implosion .. Wait a minute , thatuhh not funny

 

Last edited by jbrew; Dec 6, 2006 at 06:41 PM.
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Old Dec 6, 2006 | 06:48 PM
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Where do you get P.I. heads? Do they make a noticeable difference? Are they smog legal in CA?
 
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Old Dec 6, 2006 | 06:52 PM
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Originally Posted by Faster150
penile insert?
he is correct.
 
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Old Dec 6, 2006 | 07:19 PM
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Originally Posted by Patman03SprCrw
he is correct.

NOOOOOOOOOOOO , your kidding right?


Wonder if the girl next door has some, I will have to ask her that one..If she say's yes , then I'm a beleiver
 

Last edited by jbrew; Dec 6, 2006 at 07:28 PM.
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Old Dec 6, 2006 | 07:24 PM
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performance improved
 
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Old Dec 6, 2006 | 07:41 PM
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Originally Posted by flareside4life
Where do you get P.I. heads? Do they make a noticeable difference? Are they smog legal in CA?

They are the heads that Ford put on the 5.4 engine in 99, and on the 4.6 engine in 01-on the F150's anyway. You can find them in a junkyard off anything from a E-250 van to a Stang, or on ebay for about 600 bucks a set new, or cheaper...

Along with the heads came different pistons (dished out more to keep compression low) and a little different intake. It boosted the 5.4 from 235 HP to 260, and the 4.6 from 220 to 231 HP, so yes they make a difference. Not sure on torque numbers.
 
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Old Dec 6, 2006 | 08:09 PM
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Originally Posted by Bartak1
They are the heads that Ford put on the 5.4 engine in 99, and on the 4.6 engine in 01-on the F150's anyway. You can find them in a junkyard off anything from a E-250 van to a Stang, or on ebay for about 600 bucks a set new, or cheaper...

Along with the heads came different pistons (dished out more to keep compression low) and a little different intake. It boosted the 5.4 from 235 HP to 260, and the 4.6 from 220 to 231 HP, so yes they make a difference. Not sure on torque numbers.

Bartak , do you have to ugrade your pistons to install - can you just bolt them on or no?
 
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Old Dec 6, 2006 | 08:43 PM
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Yes, you can just bolt them on, but your compression will raise up to around 10.5 or so (cant remember exactley what it will go to).

With that high of compression you will HAVE to use premium gas, and wont be able to add and kind of forced induction. Other than that it will work just fine.
 
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Old Dec 6, 2006 | 08:53 PM
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Okay, so I can without any kind of comp mod and it will accept a tune over my 98 heads.

I guess I don't quite understand - been told if I get the PI's then I need a comp as well. That's the point where I opt out , I don't want to get involved that much - to where I would nee a new PCM . No ones explained exactly what you need for the conversion to work and be beneficial. I've just gotten bits and pieces.

I have a 98 5.4L - Without the piston upgrade would I still be able to achieve 260 HP.
 

Last edited by jbrew; Dec 6, 2006 at 08:57 PM.
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Old Dec 6, 2006 | 09:18 PM
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I guess I should have been a little more specific, Im sorry.

But yes, you will need a computer tune also...like the Xcal from Troyers. To my knowledge PI heads on a NON PI motor will not work w/o a tune.
You will also need the PI intake manifold...it has slightly different shaped runner on it where it meets the heads. I remember someone saying it might be possible to use the NON PI intake if you do some work to it with a Dremel, cant remember if it will work for sure or not though.

By the time put put on PI heads and add the tune, you should easily be at 260 HP.

If you are trying to avoid a tuner, then any head swapping or porting is pretty much out of the question...you will just have to stick with the basic bolt ons...
 
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