So I am looking at a ford 5.4l for a potential project. The plan is to buy an entire vehicle (Expedition or Navigator).
So the main question here is whether the DOHC is that much better than the SOHC. Also, do PI heads really make a huge difference?
The factory power is
DOHC (300hp) SOHC PI (260hp) SOHC NPI (230hp)
They tend to go up in price with the power. This might be a challenge build so cheap is best, but is it worth it to cheap out for either of the SOHC engines.
DOHC is definitely better, but parts are more expensive.
It's my understanding that the PI heads and intake are the way to go of you go With oem parts. Motorsport SVO and some aftermarket companies make better heads, but they are expensive.
The difference between the 5.4 and the 4.6 PI motors is pretty small. If it were my build, I'd find an aluminum block SOHC PI motor (I think the explorers had them) and I would port the upper plenum, and add whatever power adder I could afford.
I seem to recall some years back that putting the DOHC 5.4 heads on a 4.6 block was the first step of a really serious modular build.
Ok, so I should take a PI 4.6l over a NPI 5.4L? that seems counter intuitive as that is 50ci of displacement I am losing
5.4 weighs more...
Single cam 4.6 with pi heads and add boost. The 5.4 is a better starting point if budget isnt an issue and you dont mind the extra nose weight.
WildScotsRacing wrote: 5.4 weighs more...
This.
The 5.4 SOHC weighs about 100lbs more, makes basically the same power (but more low end torque), and is physically larger
A cheap power adder on a 4.6 can make more than enough power to kill its self if you turn the wick up.
My logic, which this isn't my build or money, is that I'd use the cheaper, lighter, smaller motor, and then hop it up.
Unless the chassis is ridiculously heavy and you need the extra 30-50tq, i don't think the 4.6 would leave you wanting.
This probably isn't what you want to hear, but Coyotes have the same bell housing bolt pattern. What with all the videos of Mustangs running into things (cars, people, buildings, etc.) I'm thinking you can probably pull a good one out of a wrecked car for not too much.
Long term, a coyote is definitely an option. Just not for challenge money.
What about controlling the automatic if I run a megasquirt on the engine? I know I can use a microsquirt but that is another $300.
The other thing to consider is the spark plug debacle(s). The early SOHC mods couldn't keep the plugs in, the latter ones wouldn't let the plug out. The DOHC engines never had those issues, or the mods after 2009(?).
If you want cheap 4v heads look for lincol intech. I know they came in the suvs and they are much cheaper around here. Dont know if they are as good as the 4v cobra and mach 1 heads but something to look into.
Cactus wrote: This probably isn't what you want to hear, but Coyotes have the same bell housing bolt pattern. What with all the videos of Mustangs running into things (cars, people, buildings, etc.) I'm thinking you can probably pull a good one out of a wrecked car for not too much.
singleslammer wrote: What about controlling the automatic if I run a megasquirt on the engine? I know I can use a microsquirt but that is another $300.
Household light switches (this is a GM but id guess you could rig something similar).
In reply to Robbie:
I remember seeing that somewhere. Completely forgot about it. For a challenge car, that would be perfectly fine
In reply to Opti:
That is kind of my best bet is the Navigator with the initech 5.4l.
I am not sure if the lessor weight of the 4.6l aluminum is worth it up front. Long term, totally.
Cheapest power from a mod motor would be way easier to piece together IMHO.
Non PI 5.4+ 2v PI heads+ BBK "tuned" short headers($75 C-list)+ MS+ Tremec 3650(cheaper than controlling the auto)
The 5,4 is a weight penalty but would have a way fatter torque curve than the 4.6, especially after the PI head swap. The Tremec would not need any electronic control.
If there was any chance of a power adder I would stick with the 4.6, as the 5.4 has the same rods that bend at the same threshold.
The Non-PI shortblock and the PI heads will up the compression. Gasket match it as it goes together and would be a fun settup.
I think there are better sources of HP than a Mod motor.
Building a stroker 460 right now.
singleslammer wrote: What about controlling the automatic if I run a megasquirt on the engine? I know I can use a microsquirt but that is another $300.
If you're on a challenge budget, what do you want to do that the stock Ford ECU can't do?
In reply to Will:
I don't know what sort of tuning can be done on the cheap. What are my options and how far will they go?
In reply to singleslammer:
Moates will do anything you want to do and is the go-to for the Ford tuners I know, including the guy who tuned my Supercoupe.
In reply to Will:
That is nice. I think that covers all my needs if it will work with ecus up to 04
Is it possible to run a 5.0L (coyote) on the ecu from one of these trucks? I have been looking and I don't know if they have that much flexibility or similar enough connectors on the harness to make it worth the effort?
I guess it depends on exactly what your goals are from the motor. Def get the PI heads, better starting point. The DOHC make more power more easily, but make everything exponentially more expensive.
I made 615 rwhp from my SOHC 4.6L in my 2000 Mustang GT. 17psi from my Vortech. Forged everything. PI heads but heavily ported. I ran an SCT switch chip that I could load multiple tunes on.
Fair warning though, mod motors are not cheap to build. and they need boost to make big HP.
So plenty of opinions on DOHC vs SOHC, and PI vs NPI, but no mention of 3V yet...Any particular reason?
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