tristanratliff

I found info but I couldn't find a definitive write-up

Here's what I have: 98 F-150 2WD, Auto, W-Vin 4.6 engine (Romeo I believe).

Here's what I've read so far,

blocks are the same, the difference is in the heads and intake. ( i read somewhere that the exhaust manifolds may be different).

I've also read its pretty much bolt in, I can continue using my factory ignition and computer and wiring.

I need to make a place for the second temp sensor.

What have I missed and am I right so far? Thanks guys and gals!

imp

Forgive my ignorance? What is "PI"? imp

tristanratliff

PI stands for performance improved. PI engines started around 2000-2001. The pistons, heads and intake manifold are different giving around another 30 hp i believe. my numbers may be slightly off but that is the gist of it. The heads have larger ports, the intake manifold is redesigned to take advantage of the heads and so on.

BossRacing71

The "PI swap" is a very common upgrade among the Mustang crowd. But here's the basics: There are 2 versions of the PI heads: Windsor and Romeo. The Windsors came out in 1999/2000, found mostly on Mustangs and Crown Vics. The Romeos came out in '01, and are the more common and popular version.
While there are physical differences between the W and R heads, there are no major differences between the 2 heads performance-wise. The Romeos can be identified by their 11-bolt valve covers, while Windsors are 13/14 bolt covers. Dropping the PI head onto a non-PI (NPI) bottom end raises compression to around 10:1 - 10.4:1(a few tenths higher than a stock PI motor), depending on head work etc. and this along with the stock PI intake and cams, is good for anywhere from a 35-45 hp improvement, without even pulling out your tuner. Now raising compression WILL send your torque up the power band, but the 4.6 loves rpms anyway. The trick is to make other changes to make the upgrade useful to trucks.
I'm planning on doing the swap on my truck this fall/winter, in conjunction with an upgrade to 35s and 4.10 gear swap. I've already started researching combinations that'll be "truck friendly".
There is so much info on these swaps on the Mustang forums, I'd suggest trying Corral.net or SVT Performance. I could write a novel, as I've done the swap a couple times on my Stangs. I can assure you it'll wake up ur 98 like it's born again.

BossRacing71

The PI swaps I've done were with the '01 and up Romeo heads. As I stated in my post above, the Windsors are slightly different. They require a 13/14 bolt valve cover(Romeos are 11 bolt), and I THINK a Windsor style timing cover. The intakes I THINK are the same. Not sure if the Windsor timing covers have the mounting holes for the coil packs. If not, you'd either have to fabricate, or add in a COP swap (there's a kit for this). The Romeo PIs bolt right up to the 98 and older NPI timing covers. The exhaust manifolds are a straight bolt-up either way u go.