4.6 to 5.4 swap

Rolltide1006

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Hey guys,

I have had my 97 since high school and am finally able to afford building a new motor for it (280,743 miles as of now). Was thinking of building a bulletproof 4.6 motor and quickly realized how expensive it was going to be. I heard about swapping to the 5.4 and am curious what yall's thoughts are.

Thanks
 

Leo 5.0

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Ahem

PROS
-----------------------
Easy
Just swap the 4.6 sensors, and keep your harness.
The oil pan needs a little pinging with a hammer or some other object on the fins, but other than that it's about 95% direct.
amazing torque from right off ilde to redline
Can run on stock tune
5.4s are generally cheaper than any PI 4.6
instant power, at any time, like a posi blower on a 4.6
If you do bolt ons, like cams and TB, cai, they all fit.
UDPs will work.
Tire burning takeoffs in 2-3 gear.

CONS
-------------------------
Little extra weight
You need a new flywheel and clutch, IIRC it's the windsor type you swap to. (not a con to some, but any extra replacing of things that already work is a con to me)
Longtubes if you want them. must be custom made.
FRPP shorties, BBK shorties, or stock manifolds are your only header choices(shorties will give you some gains on this setup, so it's been said)
The intake may cost a bit more than when I did it. $600+
You will have to mod your midpipe a tad(some don't, but budget accordingly in case)
redline is a little lower (5500)
A tune will make it run amazing (little extra cash for that)



But for a street only car, it's a blast.
For a drag car, with the right suspension, it's a low 13, high 12 direct swap.
But don't take my word for the racing ability, as I've never raced mine, it was for street.

But if a cheap NA street car is your plan, it's a pretty good swap.
As I mentioned, LOADs of torque right off idle.
 

DeepList

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What are your goals are for the car? The main thing to keep in mind is that the 5.4L is considerably heavier than the 4.6L. With the 5.4L, in stock form, you'd notice an increase of maybe 80 ft lbs of torque. The HP gains would be very minimal, if any. A lot of people now are running 5.4L engines with 4v C heads and Coyote or Boss intakes. The problem with 5.4L running 4V heads, besides the weight of the 5.4L's iron block, is finding an intake for it that doesn't cost a fortune, or require a ton of fab. 4.6L intakes won't work because the 5.4 has a taller/wider deck height, and although there's spacer/adapters out there to use 4.6L intakes, they're a waste of time. They are known to leak and not to mention, the change in injector depth changes the fan pattern of the injectors. Personally, I'd stick with building a 4.6.
 

Leo 5.0

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^^^
HPS intake as I mentioned.
sure you can mod your intake, but spend the extra and get solid gains and a flush fit under your hood.

And she's heavy I'll agree 1000% with that.

You can offset some of that weight.
But that is just some more cash as well.

Was it like 75 or so extra lbs?
I forget
 

96blak54

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N/A 2v? ...If your goals are quicker street strip, high reving rpm, low et's and a competitive chance...stay with the 4.6l.
If you want nasty amounts of driving torque because you drive the car everywhere and dont like running at 2000+ rpm because of low gearing and dont mind being the under dog then a 5.4l is for you...unless you switch to Tfs heads. Tfs has changed the rules for the 2v 5.4l.
 

RichV

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On the weight, a fully dressed 5.4, is it heavier than a dressed iron headed 5.0? Just curious.

We have a 5.4 in our 08 Expedition, and it moves that brick very well. A lot of top end power, even for the truck cams. It would be tire-fryin machine in a little SN for sure.
 

Rolltide1006

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Thanks for all the feed back guys. My goals are to have 300-315 rwhp and 350-380 rwtq. I'm trying to find a good used 01-04 5.4 so it already has the PI heads. I'm going to keep the block/heads and gut the motor. I'm going to send the block and heads off to get re-done at our machine shop and buy a new all forged rotating assembly and stage 2 cams. Are my hp and tq goals too high for what I am building? One day down the road I do plan on putting a SC or single turbo on the thing, but for now I want to keep it N/A until I obtain a 2nd vehicle. Thanks again for your help
 

gtwo

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Port the heads and maybe. Torque,no problem. The hp is the battle. Get the hps, don't even consider the plates.

If your building a n/a track car, 4.6

If your building a n/a street car, 5.4

If your boosting it for either, 5.4.
 

96blak54

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Aluminum 5.4l blocks are in the Ford Gt and Gt500's. No navigators, but the aviators have aluminum 4.6l blocks.
Your hp goals are feasible but not at low compression and not without long tubes. 290rwhp is all your going to get with ford heads at low compression.
317rwhp ford heads is the most ive seen dyno'd and the guy had stage3 heads, long tubes, cams, hps intake, 5spd and (at the time what was concidered)high compression.
Ford heads are the choke point in the equation.
But the torque!!! Oh man the torque!! You know when your on the streets gearing down to get the engine in battle zone......not with the 2v 5.4l....just push the pedal in.
 

Rolltide1006

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Love hearing that the torque will be there, but man I would love to do at least 300 hp. What if I bored the block out 20 or 30 over with P&P PI heads and stage 2 cams? Dumb question did the PI heads come on the 5.4 F150 and excursions from the factory?
 

96blak54

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Boring will definitely improve the torque!.LOL
Pi head were introduced 100% in '02 in all modular vehicles. My suggestion is to source out a set of '04 pi heads. Reason is the sparkplug hole has 9threads compared to the previous 4threads and those are notorious for blowing out sparkplugs especially in a 5.4l. Others will argue this but why fail to whats known.
Boring the block is always a great idea but be sure to research if the 5.4l can be took to .030". I know the early blocks were skimpy with bore material untill around '02 Ford added 18lbs more material to the bores. So seek out an '02-up block if an over bore is planned.
 

duff daddy

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I wouldnt waste my time with an iron 5.4 unless you will bore and stroke it. That motor is heavy and as mentioned intake choices are limited. The spacers from the intake to use a 4.6 manifold are ok but the amount they change the spray pattern of the injectors, has been subject to debate for sometime.
 

96blak54

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Adapter plates = no no. Just dont! Injectors spray directly onto the port floor creating port tracking in turn washed down cylinders, poor atomization, combustion. ...the list goes on with port tracking.
 

gtwo

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Ive been told weight difference is less than 50lbs.
 

duff daddy

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Adapter plates = no no. Just dont! Injectors spray directly onto the port floor creating port tracking in turn washed down cylinders, poor atomization, combustion. ...the list goes on with port tracking.

Thats basically what i said "they are ok" but not great. They will get the job done.
 

D3VST8R96GT

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Not much out there for stroking the 5.4

6.2 crank cost a lot of money and the piston speed would be crazy......

The D3V
 

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