I have just went over 210,000 miles and I'm ready to upgrade the 4.6 to a 5.4, my question is do you have to use an engine out of an 1998model or can a newer year be used?
Mike

 

I guess you allready know that it's not just a simple engine swap? There are things that have to be changed to make this work. Have you figured in the cost of this? It might be easier just to mod a 4.6 if you are looking for more power.

 

Compatibility is like this -

If you use a 5.4L to replace the 4six , the 97 - 2003 will work but you need a tune.

If you use a 4.6L as a replacement , you can use a 97 - 99 without a tune. The 2000 has PI heads and you'll need a tune to take advantage of the heads.

The 5.4 is a fairly easy swap- you need to lengthen wires along with other mods that you do yourself.. JMC is a user of this forum and he has a writeup of what needs to be done . Use the search feature in the engines forum only for best results.

 

Can I throw a question in here too? The 4.6 from 97-04 would go in a 97 or this case a 98 model with no probs mechanically? Then, if its a 99-04 it would need a tune to take advantage of the power improved heads?(if put in a 97-98) Would something like the edge tuner work? I was thinking of getting one 4 my 97 just for fun but then I'd need a different model for a 99-04 engine correct?

 

wrong tune for a motor could turn into a big problem..
you need a custum tune...

and swiching from 4.6 to 5.4 useing the 4.6 computer is eazy

my trucks a 98 f150 4.6 now with a 5.4 2000

u can run the 5.4 without a tune because i have no problems besides
runs little weard and shifts kinda funny
but once i get my tune it should be great

im told main reson you need a tune is that the timeing is all Fed up
because the load readings are not the same when you put the 5.4
in so it jacks up the timeing

o ya and when you do 4.6 to 5.4 you dont run lean because i installed a wide band so i wouldent
have to go to the dyno to finsh my custum tune and i dont run lean at all

 

It is an easy swap. i have a 2001 5.4 in my 97 4.6 truck. i had to fix the exhaust, lengthen the downpipes an inch.then you have to fab a small bracket for the pass side coil pack. when you get a different engine. go ahead and get ALL the manifold bolts loose so if later one of them breaks, you will have an easier time swapping the manifold gasket out. getting them out in the truck is not the easiest thing to do. i did not have to lengthen any wires on mine, but i had to cut the knock sensor plug off and swap it for the right one. you also have to drill and tap a hole in the aluminum crossover for the coolant to add an additional temp sensor that is on the 4.6 that isnt on the 5.4. check my gallery and you will see it. i also added a taurus electric fan while i had it apart and my 4.6 had 8 rib setup so i swapped it all onto the 5.4 and only had to space out an idler pulley about 3/16". i also added a pair of comp cams to it while it was out.

 

Thanks for the info..
Mike

 

I did this swap back in Jan. of 2004 with the help of JMC. Read this thread which contains much of the information you will need to do the swap. My truck is a 1998 3dr. Xcab 4x4.

https://www.f150online.com/forums/sh...ghlight=sclime

I did have Mike Troyer tune a chip for it as I was running way lean. He tuned it for 92Octane and I have about 45k miles on the new motor. The motor was a Crate 5.4 (2001) from KarKraft.com.

I would do this again anytime and have also thought about a 5.4 swap for my 1998 Mustang GT.

Good luck.

 

Thanks for the advice guys. We can not decide between the PI heads on to a 1997 F150 3dr 4x4 4.6L or swap out to a 5.4L. We just got a small tractor and trailer and our truck just does not pull it well. Also use it to pull the cobra to the track and need more uummmphhj. I guess the 5.4L may be the way to go.

 

Well you have to look at it a few ways and decide from there. Is there a possibility that the 4.6 with 200K miles is just a bit tired and needs to be refreshed??

Do you think that even with a fresh 4.6 you would still be lacking the power you want??


If it were me I would just get a new shortblock and limit the mods needed to make things work. Get a Stroker motor as the longer stroke will increase tq. Get the new block with the same dish as your factory pistons, then by adding the PI heads you will increase the compression ratio effectively giving you more hp & tq. Since it is a 98 with that many miles when have you last had your diff's rebuilt? Chances are they are tired and worn out. Up the gear ratio and rebuild the diff's and it will be night and day even with the same tired motor.

Something else to consider, when the 99+ PI heads and intake came out the guys with non PI mustangs were making the swap like crazy. The swap as I said above raised the compression ratio. I can't remember how much it raised it but it was enough that a non PI motor with PI heads were making more power than a stock PI motor. I only say this because there is the possibility that simply swapping to PI heads could bump your compression enough to make you have to run either 89 or 93 octane vs the 87 you can use in your motor as is.