5.4L 4V Swap?

[95PGTTech]

I've been pondering the 5.4L 4V swap since we've purchased this car. I think it stands to reason that since the 4.6 2v --> 5.4 2v swap is so direct bolt on, that the 4v --> 4v swap would be equally the same (all 4.6 sohc --> 5.4 dohc writeups state wiring harness and accessory changes, so they should be the same, and they look externally similar, doing a lot of cross referencing part numbers at work and they seem pretty similar).

The difficulty or need for modification involved with the swap is the least of my worries, as I have a ton of car background experience and making parts is nothing new for me (come on, how much aftermarket backing do you think probes have? :rollinglaugh: ).

Some of our concerns:

1. The 5.4 makes its 300ci with a greater stroke...which, as opposed to a greater bore, typically does not fare well for high-rpm power. We both really like the huge powerband in the car and don't want to disturb that.
2. adapter plates are a bandaid
3. how will the greater weight of the motor upset the braking and handling balance of the car? we're feeling out a 03-04 IRS swap, so that's a little more weight in the rear, but an iron block is inevitably heavier...as you can tell, roadracing is our priority with this car
4. the 99-04 navigator, which is the most likely donator, is not easy or cheap to find, and is rated at 300/355. Although the cobra r is a perfect example of how heads and a intake can get power out of the motor, we're wondering if it's really worth the trouble if no one has anything but adapter plates.


one of the thoughts we had was (being on the trigger for a used KB 2.2 blowzilla anyway) putting our current B heads with a turbo valvetrain on the 5.4 bottom end and putting the KB on top to forget the whole intake manifold deal. would it be a better idea for us just to find a 5.4 bottom end to work with?

 

[Magic]

1. The 5.4 makes its 300ci with a greater stroke...which, as opposed to a greater bore, typically does not fare well for high-rpm power. We both really like the huge powerband in the car and don't want to disturb that.
2. adapter plates are a bandaid
3. how will the greater weight of the motor upset the braking and handling balance of the car? we're feeling out a 03-04 IRS swap, so that's a little more weight in the rear, but an iron block is inevitably heavier...as you can tell, roadracing is our priority with this car
4. the 99-04 navigator, which is the most likely donator, is not easy or cheap to find, and is rated at 300/355. Although the cobra r is a perfect example of how heads and a intake can get power out of the motor, we're wondering if it's really worth the trouble if no one has anything but adapter plates.


one of the thoughts we had was (being on the trigger for a used KB 2.2 blowzilla anyway) putting our current B heads with a turbo valvetrain on the 5.4 bottom end and putting the KB on top to forget the whole intake manifold deal. would it be a better idea for us just to find a 5.4 bottom end to work with?

the 5.4 will offer more torque when compared to a 4.6 motor to motor any day of the week. Which is a good thing to have to aid in acceleration.

The reichard racing adapter plates arent something that would give me a cause for concern. Easy way out and they do work.

Also, if you want to add the 2.2 KB your B-heads to a 5.4 short...you will STILL NEED adapter plates due to the tall deck height of the motor.

If you want a true bolt on intake for the 5.4 DOHC (so you dont have to use adapter plates, but WILL need to fabricate up some inlet piping), look to our friends down south in Australia where they have these motors in passenger cars.

 

[95PGTTech]

there is really only information on the 4.6 2v --> 5.4 2v or 5.4 4v swap. The 2v --> 2v is almost a direct bolt in swap, but the 4v requires a lot of modifications including accessories and wiring harness. wouldn't it stand to reason that the 4v to 4v swap "should" be much easier than a conversion?

I know of one new girl on here with a 5.4 4v, maybe she or others have some insight?

 

[r3dn3ck]

Sorry I found this so late. Here are answers:

No, we have lots of info on the 4v swap. You're just not looking in the right place and you're thinking that 2v and 4v are really that different. Check out my sticky in the 4.6 tech section of mustangboards.com. Don't bother reading it, just post questions at the end with a brief introduction of yourself. I have a few 4v swappers that troll looking for guys to help. One of them is currently doing a swap so you could learn a lot from him.

The powerband with the right cams and heads (fully streetable) can easily jump to 7000+rpm. Don't trip. It's cool. There's plenty of RPM to go around. Even with the long stroke. You just need heads/cams/intake/exhaust that can fill the holes with air. FWIW, Al Papito runs his to 8800+rpm.

There are other intake solutions out there and they don't need adapter plates. Do you REQUIRE a stock hood or can you deal with a small to medium sized cowl hood as a requirement? That will determine the intake route. Don't trip though, there are intakes to be had. GT500 blower setups can even be used.

I ran 350# coil over springs before the swap. I'm about to put on 375's. I do autocross racing. For the street it was barely noticeable. There was a little change but not enough to change the normal handling very severely. I'd probably want a stiffer than stock front sway bar though as some of the weight moved a bit higher and pulls the CG up a tad. The extra sway bar in front helps keep the front end plow down if you race. If not, don't worry.

400rwhp is no trick on a 4v 5.4 if you're willing to stab some cash into it. You'll need cams no matter what if you want to rev to 6K or higher.

Now, go sign up at Mustangboards.com and post in my sticky. Don't make me come and grab you by the ear.