Hi Everybody!

Well, the 4.6 in my stepside 97 F150 is weak & underpowered with low compression and recently started sipping some coolant which I found in the oil.

It's peanut butter jelly time!! Time to have some fun with it!

We all know that this motor is too small and not powerful enough for this truck when pulling or hauling, so I considered a few things. Swapping in a 5.4 which seemed like opening a can of worms. Next thought was rebuilding my 4.6 with a modmax stroker kit but that's very expensive and I can't find any real proven power gains with doing just a stroker kit. I'm sure it'll help but would it be worth the $2K that I'll spend on just the motor alone? At this point, this is probably my plan b, if the below won't work...

My final and hopefully "plan A" thought: I' found a 4.6 motor from a 2001 crown vic police interceptor on craigslist for $400. I'm pretty sure that this motor uses the PI heads so there's an extra 15-20 HP right there, I'm not sure what the other differences are in this motor for power & performance as I'm told it's classified, but will have good power gains over my 1997 4.6L.

Hopefully you ford geniuses will know these answers, or even done it yourself.

Upon my initial research on using a 2001 interceptor motor, I've found that I'll need to change the intake & exhaust manifolds... no big deal as I was going to add headers/exhaust and was considering a performance intake manifold and cold air kit anyway, (maybe even 75mm throttle body). Pretty sure mine (manual transmission BTW) uses an 8 bolt crank, and the 01 motor will have a 6 bolt, so I'll need to change the flywheel. No big deal, I've found them new on ebay for around 70 shipped. The only other things I can think of will be to change the C.O.P. ignition and use my existing coil packs?

Does all this sound correct? Is there anything I'm not thinking of? Anyone know about sensors, placement of sensors, wire harness, computers, ect...? Will these from the newer motor jive with the Canadian 1997 Windsor built truck?

I also considered just selling it and buying a newer 99 or 2000 with the 5.4, but I really like this truck. I know some history and once this is done it'll be a solid truck and I'll have very little to worry about for a long time as I'll also be putting in a new clutch and rebuilding the tranny.

Any thoughts or opinions on if it'll work or not? All help is appreciated! Thanks guys!

-Phil in Denver, CO

 

Use your existing wiring harness with whatever you swap into it and get a tune. It will be a million times easier that switching to cop which i am pretty sure the 4.6 has. Personally i would just do a 5.4 swap. Their is quite a few guys on here that have done them and it isnt hard to do. After i did the swap to the 01 5.4 from the 97 4.6 it was like daylight and dark. It was so much more driveable and it didnt downshift near as much. The 4.6 should have never been in a f150 from the first place. The swap is fairly straight forward, extend a few wires and the exhaust was the biggest thing i can remember. You said you were doing headers so the exhaust wont be an issue.

 

Definatley not too worried about the exhaust either way I go as I wanted to do a complete new and true dual exhaust, including headers. Colorado is starved for oxygen as it is so anything we can do to make our motors breath better usually helps a ton!

When I baught the truck, I knowingly sacrificed the larger motor to get the manual tranny... I'm tough on transmissions. That motor is way underpowered for any vehicle of that size/weight.

My first initial thought was to swap in a 5.4, I guess I chose against it and started thinking along the lines of a beefier 4.6 because I heard too many people having problems with 5.4 compatability and getting it started after the swap. I'd hate to be stuck with a truck that won't start. And whatever I do, I'll be using my old coil packs or upgrading to performance packs as that seems like the easiest option keeping in sync with the trucks ignition computers.

I've changed numerous motors, done a few Jeep t-case conversions and have stripped/parted about 30 cars (Saabs, BMW's & Rovers) in the past to give you an idea of my technical abilities, but it's much easier taking them apart then putting them back together. I'm sure I'll fiigure this out but I'm certainy no master tech when it comes to fixing them or custom stuff like this. Alldata is my friend.

Stupid question. What does everyone mean when you say "get a tune". I don't have a custom programmer or anything, will I need one? Is it as somple as taking it to a Ford specalist and telling them "I swapped in a XXX motor, please program my ECU"?

Thanks again!

 

You need to keep in mind that the manual tranny is a light duty unit and does not like being hooked up behind a juiced motor.

 

Good call on the tranny. I will be rebuilding it in the process.

It's also good to note that this is NOT my primary vehicle. It's used only for the heavy Colorado snowstorms, towing, hauling, ski-trips, and to get to that remote camping spot. I do not intend to race it or rod it in any way. Just needs more power for the above mentioned activities. Overall I'm a pretty calm driver, when I'm in the truck...

 

You also have a 3500# towing limit due to the tranny. The weak point is the input shaft. The OEM clutch is kinda soft for towing too.

 

3500#? I checked all that info before buying the truck and this is the first time I've ever heard that about this truck. I'm nearly positive that the door sticker says either 7700 or 7200# max towing capacity. Also, it came equipped from Ford with a Class III hitch, I can't imagine that ford would install a class 3 hitch on a truck that couldn't even tow it's own weight. I'll need to do some research on this but if true, it's probably pretty simple to beef up the input shaft and any other weak links while I'm in there.

 

The door sticker doesn't show max towing weight - just truck GVWR. The max towing capacity for a 97 4.6, depending on equipment, is from 2000# to 3500# with a manual and 2000# to 7200# with an automatic.

 

PI is the power improved...


the "POLICE INTERCEPTOR" wasn't more powerful it just had a better oil cooling system and has been idled for ever...


take the mileage and multiply it by 3 or 4 to get the equivelant it's been run to be honest you'd be bettter off getting a taxi motor

 

5.4 swap

 

I knew PI didn't mean interceptor but rather power improved. Good to hear some comments on the police motor, and that's a very very good point.

I have found 2 police motors both with around 65K on the clock, actual wear is unknown! Whenever somebody talks about the 4.6 being underpowered, it takes me back to thinking about teh 5.4 swap and how difficult it would actually be. There are a few 99+ 5.4's locally with the PI heads for under $1000....

 

5.4 swap not difficult

 

The 5.4 swap on a manual tranny is real easy. Use your 4.6 engine harness and ignition and all will be fine. While the increase in torque will put a stupid smile on your face the broken transmission will take it away. The weak point is the input shaft bearing. It is a tapered bearing and uses shims to take up the slack. Once the bearing starts to loosen up the shaft walks and you chip teeth.
Every time you do a clutch job replace the pilot bearing and check the play on the input shaft. Reshim and or replace it. I am on my 5th or 6th tranny. On one of my destroyed transmissions the input shaft moved like a joy stick.


.

 

Allright, it was my original idea when i first baught the truck so you've all convinced me. Thanks! 5.4 swap it is. I found a rolled 01 Expedition with a strong a 5.4. Unless something changes in the next week, I'll be buying the whole expo for $1500, as long as the motor will work.

Next question, will a 2001 5.4 from the donor expedition work in my 97 F150??? providing I change the Exhaust manifold, use my 4.6 harness and coil pack ignition and possibly change the flywheel. (not sure if it 6 or 8 bolt) Any other surprises I can expect with that much newer of a motor?

Also, since I'm rebuilding the trannny in the process, where can I find a stronger input shaft?

On a side note... JMC, you mentioned all the play and the shaft moving like a joy stick... I've been trying to track down this exact driveline play since I baught the truck. I thought I had a loose tranny mount at first because I could actually feel the play in the drive line, like excess play in a slip yoke or something, and I can definitley feel it in the tranny which is why I want to do a rebuild, but everything in the driveline is tight. I bet this is where it will be when I take it all apart! HA! Thanks for the tip!

 

Oh and JMC, I've read thru your swap notes many, many times over the past few months and have seen them posted on a few sites. Very informative, thank you!

If this works out, I'll have a lot of 2001 Expedition parts for sale *cheap* within the next few months... everything but the motor!