What problems have you guys run into while doing a 4.6 to 5.4 swap (if), i have heard from friends about problems and hastle with the harness swap and i am just wondering if there is a walk through out there maybe.

 

the 5.4 harness will swap right over, plug right into the same plugs on the firewall

 

k good. Maybe i will stop listening to friends and start listening to a pro forum! thanks dude

 

only concern i have will be the year of trucks.

im not positive, JMC knows much more on this than i do, but i thought there was a few differences between the years. i assume some of it has to do with coil packs vs cops.

 

Yeah, my roomate has the 99 5.4 and thats about all we can find thats different. But how is it going to work when i get the new engine in, as far as the coil pack brackets get removed and what not. Is there such a thing as swap instructions for this? Or should i just talk to jmc?

 

If all else false, post a thread eh?

 

i thought the 99+ 4.6 had cop. if thats the case then the harness should hook right up to the 5.4.

 

Here read this.

Notes for 4.6 to 5.4 swap Revised 25 June 2008

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. You will need to have a muffler shop modify your 4.6 exhaust to match up.

Ignition: All 5.4 engines use Cop ignition. . 2000 and later 4.6 use COP ignition. 1997-99 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 applicable. 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 may be too short so measure or test fit the harness to see if 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.

Torque Converters.
4R70W
ENGINE Stall Speed Multiplication
4.2 1978-2330 2.3:1
4.6 2105-2505 2.3:1
5.4 1830-2190 1.9:1

4R100
All ?????? 2.2:1
If you swap a 5.4 into a 4.6 engine bay and use the 4.6 converter you will multiply the 5.4's torque at a higher rate and at a higher stall speed which will put the torque at the transmission input shaft close to the limit if not over the limit of the 4R70W. The 99+ 5.4 produces 350 ft/lbs of torque. 90% of that is available at 2000 rpm. The stall speed of the 4.6 is above the 2000 rpm range so more than 90% is available. 350 ft/lbs x 2.3(4.6 multiplier) x 90% is 724.5 ft/lbs.

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.

Knock Sensor:
The 97-98 99 4.6 uses a 2 wire knock sensor. The 97-98 5.4 has 3 wires of which one is a ground. Both have a Yellow /red wire to pin 57 on PCM.
1997-98-99-2000-01 Yellow/red to 57 on PCM 4.6 Same for 5.4.
97-98 Pin 91 feeds power for 4.6 and other components. Same for 5.4
1999- 2000-01 Pin 32 for power. Same for 5.4
2002+ Cannot confirm.



Accessories: Some engines have 8 rib serpentine belts and some have 6. Be sure to check so that your accessories have the correct pulley.

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.


Regards

Jean Marc Chartier

 

Thank you so much jmc!!

 

JMC, what if i have the complete long block of the 5.4 with all the wiring harness and COP? How does it run off the 4.6 coil packs?

 

Also, do i gain torque by putting the 4.6 converter on the 5.4 and is that good or bad thing? What will i have as far as risks?

 

By far the easiest thing to do is transfer your 4.6 harness and coil packs to the 5.4 engine and use the 4.6 PCM.

The 5.4 torque converter stalls to around 2190 rpm. The 4.6 stalls to 2500 rpm. The torque output of the 5.4 at 2500 is about 350.
The 4.6 converter multiplies at a 2.1:1 ratio. So you will be putting 700 ft-lbs of torque through a transmission rated at 700. There is no room for error.

Regards

Jean Marc Chartier


Regards

Jean Marc Chartier

 

But if i do that, it won't run to par until i get it tuned correct? Because everything is set up for a smaller black aka 4.6, correct?

 

That is correct. The factory PCM is set to run a 4.6L displacement not 5.4.

Regards

Jean Marc Chartier

 

Alright, no problem, i needed that done soon anyway so that works out. So when it comes to tapping the intake, whats the best tool to do so? Do you have any step by step instructions or any instructions of the sort to help me do these modifications. Just kind of scares me, i don't want to ruin the pi intake.