my 4.6 has 153,000 miles on it and it really shows. Both of my head gaskets are leaking really bad, i have a freeze plug leaking, oil lines drip drop, and everything else. Anyway. I figure I'd just find a 5.4 to swap in since repairing the heads would cost more than the head job, not even close to worth it. My question is, can I just get a good 5.4 longblock and swap on my intake and all the other goodies or no? I know these are mod motors and sopposively everything swaps over, but what would i have to change? Injectors? PCM?


thanks

 

https://www.f150online.com/forums/sh...light=5.4+swap

 

Thanks. I went through that thread but I guess I missed the part about the direct swap over.

 

Just so you know the 98 4.6 to a 5.4 is not a direct swap, right now you engine has two coil packs, and the 5.4 has COPS, it's a totally different ingnition system and you computer and wiring harness will have to be updated to the new system, hopefully you get this before it's to late

 

thanks. thats info that I needed. still alot more uncovered, but in time I will find it.. thanks guys

 

a 98 f150 with the 4.6 to 5.4 does not need any wiring changes or ignition upgrades. You can use the coil packs with the 5.4, it will work. You just need a custom tune from mike t @ troyer performance. You'de need this anyway. But if your tranny has that many miles a 5.4 might just accelerate the destruction of it.

as for swapping heads, yes they will work. but the intake will not. the 5.4 has a wider intake.

call mike T at troyerperformance.com, he will help you out with everything you need to know and what you would need to get your running correctly.

 

I would recommend a 99+ 5.4 engine. It has the Pi heads which will give you a bit more power over the 97-98 engine. Use the 4.6 harness and modify it to fit the 5.4.

I added a few more notes.

Notes for 4.6 to 5.4 swap

Exhaust: The collectors on the exhaust manifolds are set at different angles and locations. The 4.6 exhaust will not bolt up to 5.4 manifold.

Ignition: All 5.4 engines use Cop ignition. 97-99 4.6 engines use coil packs. It is easier to wire your 5.4 using the harness from the 4.6 and the 4.6 ignition coil packs. If you use the 4.6 Coil pack ignition you will have to fab a bracket for the driver side coil pack.

Engine harness: The IAC harness must be relocated to the rear of the throttle body elbow. The oil sender wire on the 4.6 is too short so it must be extended. All 97-00 4.6 engines use some sort of intake manifold runner control valve. Remove it from the 4.6 and plug it into the 4.6 harness and bolt it to the engine some where out of the way. Note you can get a tune to remove its function and eliminate it all together. All 97-98 4.6 engines use an engine coolant temp sensor. Some use 2. None of the 99+ 5.4s use any. You will have to tap the intake manifold crossover pipe to fit the sensor. Some 4.6 engines (97-8) have two sensors.

Transmissions: the 4.6 and 5.4 have the same bellhousing bolt pattern. That means that all the transmissions will bolt up. All the 5.4 engines have 8 bolt crankshafts. Some 4.6 engines (ROMEO ENGINE) have 6 bolt cranks. You will need the flex plate from the 5.4.
Manual transmissions: If you don’t have an 8 bolt flywheel a flywheel from a 1997-8 4.6 Windsor engine will work. As it has 8 bolts it will bolt right up to the 5.4 crank. Remove the flex plate spacer and install a pilot bearing from a 4.6.

Tuning: It is best to have a custom tune done to accommodate the extra displacement of the 5.4.
You should be able to use the 4.6 MAF as any competent tuner can adjust for it. It is always best to discuss this with your tuner.

Misc: Both engines use the same engine mounts and their location on the block are also the same so your old ones will fit. Unbolt and place aside the AC and PS. You need to remove the intake manifold for the engine to come out. Yes there are 3 bolts on the starter.


JMC