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5.4L or 4.6L

1950 Views 28 Replies 10 Participants Last post by  BlackBullitt2615
Hey guys, Ive been looking at building up a modular motor for my Bullitt to get some more N/A power. I have seen many people increasing the displacement by moving up to the 5.4L but im not sure what all is involved with fabricating the engine bay and so forth. I was just wondering what you guys would suggest if I was to start building up a motor for my B. Just so you know there is nothing wrong with my motor in it now...just kinda want to get used to working on the motor since all I have ever played with is a pushrod motor! And it would be nice to have some more power and torque! Thanks for the input!
Shawn
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There's no replacement for displacement. 5.4 all the way if you've got the cash, then do an aluminum intake and 76mm garret. That'll work.
05102 said:
There's no replacement for displacement. 5.4 all the way if you've got the cash, then do an aluminum intake and 76mm garret. That'll work.
Yea I would imagine that would work quite nicely! Too bad I dont have enough money for all that...it would be a cheap build with a cast iron block but all forged internals...maybe get the heads reworked but other than that just a cheap build...thanks for the input!
Problem with the 5.4 is it is a wider deck (between the heads) than the 4.6, so you need manifold adaptors, and I belive there may be a hood clearance issue with the stock intake. Why not spend a little coin on new heads (I'm looking at the new Trick Flow ones for the 2 valve), nice cams, and a tune. Maybe a little more than a 5.4, not sure. I haven't priced it out. But in theory, should be at 400 hp / 420 torques to the wheels.
installermarc said:
Problem with the 5.4 is it is a wider deck (between the heads) than the 4.6, so you need manifold adaptors, and I belive there may be a hood clearance issue with the stock intake. Why not spend a little coin on new heads (I'm looking at the new Trick Flow ones for the 2 valve), nice cams, and a tune. Maybe a little more than a 5.4, not sure. I haven't priced it out. But in theory, should be at 400 hp / 420 torques to the wheels.
Thats what my goal is is around 400hp to the wheels...Is that with what I have now? I still plan on building another motor on the side that way ill have the stock motor still for collectors value if it ever gets to that point! Thanks!
If your motor is close to stock (long block), without a blower, I would say close to 270 hp to the wheels. Mild bolt ons would push it closer to 300. But this is all just bench racing. Your best bet (I think) is to pay for a good Dyno session at a reputable shop. Then you know where you stand, and from there what parts will make the most impact.

Don't forget the HotRodding Golden Rule- Speed costs money. Things like removing the Air silencer may give a 1 HP increase, but to make 100 more, costs a lot more.

So don't get discoraged that some things just cost money. Most of the others on this forum that have modded their rides will tell you some things can be bang-for-the-buck stuff (Like 3.73 gears) and others are just plain needed to make power (like headwork or heads).
installermarc said:
Problem with the 5.4 is it is a wider deck (between the heads) than the 4.6, so you need manifold adaptors, and I belive there may be a hood clearance issue with the stock intake. Why not spend a little coin on new heads (I'm looking at the new Trick Flow ones for the 2 valve), nice cams, and a tune. Maybe a little more than a 5.4, not sure. I haven't priced it out. But in theory, should be at 400 hp / 420 torques to the wheels.
What he said.
yea i dont have too much on the motor right now...just stuff that was already there including 3.73 gears and a densecharger CAI. It also has a dual 62mm throttle body from what I can figure which I know doesnt do much without other add-ons. I wanted to get headers and o/r H pipe but never really thought about head work! Might look into those trick flows you were talking about! Its either put a 6 speed in now or wait and build a motor and keep my t-3650...havent fully decided yet! Thanks again!
Shawn you need to drop GBoger a line. He did a DOHC 5.4 swap in to his 2001 a little more than a year ago and he can tell you all about it. I think all he had to do was fab some simple plates around the mount areas but other than that the last I heard from him he wasnt experiencing any major problems. He installed an Eaton blower too, I think. The photos were very impressive, to say the least. Look him up here on IMBOC and drop him a PM. I'm sure he'll be quite helpful.

Another option is the new 5.0 MOD block from Ford Racing. They sell new for around $2-K and they have the same dimensions as the stock 4.6 in the 2001. There are also stroker packages available as I am told that will bump your CID significantly past the 5.0 size.
TXBLUOVAL said:
Shawn you need to drop GBoger a line. He did a DOHC 5.4 swap in to his 2001 a little more than a year ago and he can tell you all about it. I think all he had to do was fab some simple plates around the mount areas but other than that the last I heard from him he wasnt experiencing any major problems. He installed an Eaton blower too, I think. The photos were very impressive, to say the least. Look him up here on IMBOC and drop him a PM. I'm sure he'll be quite helpful.

Another option is the new 5.0 MOD block from Ford Racing. They sell new for around $2-K and they have the same dimensions as the stock 4.6 in the 2001. There are also stroker packages available as I am told that will bump your CID significantly past the 5.0 size.
Yeah I did see those 5.0 mod blocks too and that was gonna be my next option if I decided to stick with the 4.6! I think it would be neat to slap some 5.0 badges on the car and it have a purpose! I was also thinking of buying a complete engine outta a crown vic from a junk yard and just getting it machined then stroke it since the kits arent too bad...there are just too many decisions! haha Ill try to send a PM to the guy you mentioned and see what his suggestions are if I decide to go with the 5.4L! Thanks for the help!
The 5.4 swap,sounds like a great idea,especially now with the new TFS 2V heads,to let it breathe! You would need adapters to mount the Bullitt intake,but that would work really well with the heads and extra cubic inches.Of course,a cowl type hood would be need to clear the intake. The Bullitt intake isn't strained very much to fed a stock 4.6.
However,the iron 5.4 will add a weight penalty over the front wheels,upsetting the fine Bullitt handling. Maybe move battery to the trunk,and other weight reductions up front,to balance it out.
After a year of driving the 5.4, I have had zero issues. I am amazed at how tight the suspension and handling are still, even with the extra weight. Corners like it is on rails, get 27 mpg Hwy, and still run consistent 12s on street tires.

The only real issue with a 5.4 swap is the intake options. Adapter plates are not the greatest, but they will get you going quick.

I keep hoping that as the 5.4 swap gets more common, the aftermarket will respond with swap parts. A true 5.4 Bullitt intake would be awesome, just the way it should have been from the start.

Gboger
Bullitt 5.4 said:
After a year of driving the 5.4, I have had zero issues. I am amazed at how tight the suspension and handling are still, even with the extra weight. Corners like it is on rails, get 27 mpg Hwy, and still run consistent 12s on street tires.

The only real issue with a 5.4 swap is the intake options. Adapter plates are not the greatest, but they will get you going quick.

I keep hoping that as the 5.4 swap gets more common, the aftermarket will respond with swap parts. A true 5.4 Bullitt intake would be awesome, just the way it should have been from the start.

Gboger
Thanks for the help guys! One question...what about the emissions? Im in NC and they have the emissions testing and all so will having the 5.4L kill my chances for passing inspection? Ive heard that some places will reprogram your computer but I dont know how accurate that is. And will the trick flow 2v for the 4.6L feed the 5.4L good enough? Thanks again!
installermarc said:
If your motor is close to stock (long block), without a blower, I would say close to 270 hp to the wheels. Mild bolt ons would push it closer to 300.
Most stock Bullitts put down ~240 if I recall correctly.
The TFS 2V heads should work fine on a 5.4. Plus they will be coming out with two other versions of that head,that flow more! Give them a call.
Mus408 said:
The TFS 2V heads should work fine on a 5.4. Plus they will be coming out with two other versions of that head,that flow more! Give them a call.
Ill do that! Gonna weigh all of my options and do some pricing and ill let you all know what I decide to do! Might be ordering a block in a couple weeks! Thanks!
5.4 2-v ???

If I recall correctly Ford did produce (maybe still does) a 2-V 5.4 engine for trucks. I think I've seen a couple on E-bay within the past year.

Since GBoger claims no issues; to include good handling, tight suspension, and 12(s) in street trim then I'd feel safe to say it will be hard to argue with that success. No substitute for cubic inches. :badgrin:

Thanks for keeping us updated. :smile:

My advice is to keep in websites like KarKraft (they make those plates now I think) and others like them and see what all they come up with. If plates are available that will allow you to use a BULLITT intake and/or the Trick Flow BULLITT reproduction intake with their higher flowing 2-V heads then you may want to consider that.

I'd look in to all the numbers; to money numbers as well as the horsepower numbers and see what's best for you.

I got a feeling this is going both be an interesting thread. :wink:
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Go to www.mustangboards.com

There is a HUGE thread over there. I would actually read towards the end as most questions have been asked and answered many of times. R3dn3ck has done a swap and is always helpful on answering questions. Spend a wek on reading the thread.

Chad
M1 Tanker said:
Go to www.mustangboards.com

There is a HUGE thread over there. I would actually read towards the end as most questions have been asked and answered many of times. R3dn3ck has done a swap and is always helpful on answering questions. Spend a wek on reading the thread.

Chad
Thanks man...Ill have to devote my life for the next couple weeks to read all the info in that thread! haha But im gonna get as much info as I can to help with my decision! Do you all think the t3650 can handle the extra power? And also my tri-ax is showing signs of needing to be replaced...should I get another or go with something else? Thanks again!!
3650

BlackBullitt2615 said:
Thanks man...Ill have to devote my life for the next couple weeks to read all the info in that thread! haha But im gonna get as much info as I can to help with my decision! Do you all think the t3650 can handle the extra power? And also my tri-ax is showing signs of needing to be replaced...should I get another or go with something else? Thanks again!!
The 3650 has massive internals(huge gears,etc..)and the same gear centerline as the T56. The main issue is with the crappy syncros, Promotion sells an upgraded 3650 with a 26 spline input (and I believe carbon snyncros, need to check) that they rate for 750HP.

I currently have a T56 behind my 5.4, but I am seriously considering swapping to an upgraded 3650. I am not happy with the notchiness of the shifting on the T56, the 3650 was like butter in comparison.
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