So, you want displacement?
Installing the 5.4L Triton
As you can see, other than being a touch wider,
and the oil fill being on the wrong side, the engine looks stock.
Installing a 5.4 liter Triton V8 is a worthwhile upgrade for any 4.6 liter powered Thunderbird or Cougar. It is cheaper than installing a DOHC engine, and gives the same result.
The swap is very simple in actuality. The 5.4 bolts right into place where the 4.6 goes, using the same mounts, same transmission, and even the same electronics.
I started out with a 1999 engine, and although it came with PI heads, I already had a pair of them ported and polished, so I used them, and sold the other pair to a friend. I highly advise the 1999 and newer engines, although the older engines are also a ton more potent that the 4.6, but the newer engines have better heads.
Now, you can modify the engine for more performance, as I did, but that will all be detailed in another article. For now, lets concentrate on getting this puppy in your car and running. I will assume you know how to pull an engine, and have the engines on stands, side by side, or you would not be even trying to do a swap.
The first challenge is the electronics. The 99 and newer modular motors use a direct fire ignition with separate coils for each plug, mounted on each coil. Your older EEC-V cannot run that ignition, so transfer the coils from your 4.6 over to the 5.4. Also take the other sensors from the 4.6 and swap them over. They should all bolt right on, complete with the brackets.
The manifolds are another challenge. There is no way in the world that the extremely high 5.4 F-series/Expedition/Excursion intake is going to fit under your hood. I tried it, and I have a 3 inch high cowl induction and it would not close. You have two options. One is to procure the 99-newer van intake for the 5.4 which is a lower intake, looks like the composite 96-up 4.6 intake, it SHOULD clear the hood on 94-95's, and will on the 96-97s. I say should because, while I have the intake, it is not on my car yet, and I have a higher than stock hood. The intake should work though, but because it is 99-up, you will need the fuel rails for a 96-97 Thunderbird or Mustang, because the 99 has a returnless fuel system, and the 94--95 rails won't clear the throttle body.
Option #2 for the intake is to get the older aluminum intake for the 4.6. There are a couple of ways to deal with the difference in width from the 4.6 to the 5.4, the difference is not a whole hell of a lot, in fact very small. I was thinking that grinding would be possible to one intake, but having tried it after being shown by someone that it didn't work for him, that will not work. You will need to cut and weld a pair of manifolds, making it fit. This is what I am running right now. Use the injectors from the 5.4 on the car no matter what else you do.
Now, we have the problem of exhaust. This is easy. Hyland makes longtube headers for the mod motor in an MN12, but they run $1150. Shorties are a total waste of money, so if you do not feel like spending that kind of green, not to mention I am not positive they will fit the car with the 5.4, and even if they do, it is a fight to get them in, you can do what I did. Send your Thunderbird's stock 4.6 manifolds out for porting, extrude honing is the way to go here. Bolt the extrude honed manifolds to the engine, and now flip the assembly over.
Why turn it over, you ask? Well, while you have your engine upside-down, you will notice the oil pans are different. The truck pan will not clear the MN12 K-member for any amount of money. Pull the pan from the 4.6, as well as the oil pick-up, and install them onto the 5.4. Also, transfer the oil filter adapter and coolant hose attachment from your 4.6 and transfer it over.
The last thing you will need it to modify the flexplate on the 5.4 slightly. The torque converter pattern is different form yours, and the flexplate has an 8 hole crank pattern, making using the 4.6 plate impossible. An automatic Cobra plate will work, but is not needed. Just align your converter onto the plate, it is self centering in the pilot hole on the crank, so centering is not a problem. You will notice bolt holes that are too small for the converter bolts to fit, but they are there. Line up the converter so you know which holes they are, then drill them out to fit the bolts thru.
Now, you are ready to bolt it all into the car. I recommend a torque strap and/or beefing up the mounts somehow, as the 5.4 makes alot more torque than any 4.6 can ever dream of making.
The exhaust system will almost bolt right up. If you have stock exhaust, you will have to force the Y-pipe slightly wider to fit right. If you have duals, this is not a problem, but the stocker is tough stainless, and herd to bend, but it can be done...and only needs a little bit.
Now, once the engine is in place, those of you with the 94-95 cars and probably the 96-97 cars as well, will notice something. The oil fill tube is in the middle of the air intake path. I came up with a solution for the guys, who like me, used the older aluminum 4.6 intake mod. When I get the van intake onto the car, I will solve the problem, if it exists on the newer cars. I took a pair of 3 inch mandrel bends, and some marine exhaust hose and a pair of clamps to attach the throttle body to the MAF sensor.
This is the air intake I made up. The marine hose is flexible, so where the hood comes down, it flexes to allow the hood to close, although it is tight. It gets slightly flattened between the hood and valve cover.
The other problem is without the stock air intake, the breather on the LH valve cover is left open. K&N came to the rescue here with a small breather filter that clamped right onto the valve cover.
LH Valve cover breather
The final step in the install was to drive the car up to Longwood, Florida to Superchips. I had them re-burn the chip to custom settings allowing me to take full advantage of the engine. The results? Well, I get awesome mileage, enough torque to pull a house, and high 14s, even with the 3.08 gears. And traction problems.