Yaadilah

Can I install a PI head on a non PI engine for the 1999 F150 5.4L? I read somewhere that it can be done but also the intake manifold needs to be swapped as well.

Has anyone done this and had success? If you have, what else did you have to consider? Different head gaskets?

jprevat

iTrader: (1)

Look up pi head swap. It adds at least 70 hp Iirc but you will need heads, intake, gaskets, and a good tune to make the most of it.

Yaadilah

Do I use the camshaft off the PI heads?

jprevat

iTrader: (1)

Yes you would.

Jbrew

70 w/the 5four ? Really ? I was thinking around 30. Perhaps your closer than I think. Well here's what I know, - witnessed, - 98 block/PIswap w/LTheaders/Air force 1 intake (or any other CAI w/3" straght tube).

260 HP at the rear wheels (RWHP)

What I can't remember is gearing. May have had 4.10's ...yea, not sure there.

But the truck (98 SCab 4x4) Dyno'ed @ 260 HP at the rear with that swap. A 5four PI swap.

jprevat

iTrader: (1)

I was thinking the non pi motor was 230 at the crank. Then account for parasitic loss and you still gain 30hp. Maybe I was a little high but I doubt by much.

Edit: I figured loss at 15% or 34.5 hp

Jbrew

Unfortunately it's more than that , about double thru the 4x4 DT and weight @ 30% from FWHP - RWHP.

LT's shine the most from this set up as well. The same 98 150 was dyno'ed with shorty's first, then dyon'ed with Dynatech LT's w/spinetechs. The LT's alone gave it 30 HP 35 Torque over the shorts. If you want to look up the info, the dyno runs were posted by Joey (user Built54).

But yea, there's quite a bit more parasitic loss from the FW. I believe the Mustangs are like 15%.

Jbrew

I know another user (Dynotech) who has the 97 5four. Gaskets went bad so he went with the PI swap, but kept everything else stock/factory. Once finished, he didn't dyno but posted he didn't notice much difference in HP and Trq.

Suffice to say, headers wakes it up a bit. With increased flow, compression thru intake and heads, an air intake, exhaust and tune would be a must IMO. In order to get the most out of the mostest from this modification.

That's also about as far as you can go w/bolt-ons..well E-Fans are a nice addition. Other than that, next would be charger and perhaps head work.

Wolvee

NonPI F150's were 220hp for the 4.6 and 230hp with the 5.4.

A PI head swap will get you to stock PI Hp number and the extra compression is worth about 10hp if it's Tuned correctly. The "70hp" number gets thrown around a lot because of the 215hp mustangs.

You also have to take into account that even a stock PI vehicle will gain Hp/Tq with a tune. So gains can be exaggerated depending on where you're starting from and if you consider that the other vehicles you're comparing them with are tuned or not.

260fwhp PI engines are where we start. 270 would be a high average for an intake & Head swap. When we're talking the matter of 10Hp though, we're really splitting hairs. You can't really feel 10hp and 10hp is less than the +/- variance of a Dyno. On average you'll get up to the high end of stock Dyno tuned PI engines.

Another consideration is drivetrain loss from the stock numbers through the slush box. Even tuned with the basic aftermarket parts like Exhaust, O/R Y pipe, exhaust and larger throttle body you'd have a hard time getting back up to 260fwhp with the rwhp.

Your tire weight and Yes, even your gear ratio will affect what your dyno numbers say.


These are not race cars, nor are they even performance oriented machines. Number chasing is futile and near pointless. I tell everyone to pick a reasonable number they want, and prepare to spend twice as much as they think to get there. Be realistic with how much Hp/Tq and Gear you really need.

Carcrazygts2

99 5.4 is a PI headed engine from the Factory.