6mustang6

Well yeah. I do like the OHC designs. but im also an old school car guy. I love a good ol fashioned 289,302,351. That would be a sweet engine though, bored the 5.4 out to 5.8, then with DOHCs. Damn, We should definately be running with vettes then.

Rusmisel01GT

Sooner or later GM is gonna **** off Ford and they are going to make a 429 DOHC beast.... thats what I'm waitin on!!! [8D]

Seriously though... your comparing apples and oranges... its not even close... considering those LSX motors make more power then the 4v motors...

Somebody asked if they make a 5.4 DOHC in anything other then the shelby and Ford GT... only thing I know of is the Navigator... but I dont know what its rated at.

6mustang6

429 DOHC BEAST? OMG DUDE. And ford will not hold back, and go ahead and supercharge it. If the 5.4 lil motor can make 500 hp that 429 will be hitting 600-700 hp easy. They're already making a 5.4 DOHC with 600-700 hp in the Super Snakes coming out.

Eagle2000GT

The block is basically the same. With a SC, thelimiting factor is the rods and pistonsnot the heads. Unless you forge the bottom, the maximum is 420-450 for both. (Note: The 03/04 Cobra already had forged rods and pistons. But, it is a special case.) I've read that if you forge the bottom, then heads start playing a role again around 600 rwhp.

01snake

i dont know where you got that but psi for psi the 4v will come on top with a pretty descent amount

yea the blocks hold the same but big whoop once you upgrade that. the 4v still has 2 more valves

2002GTAUTOVERT

all being equal a supercharger on a 4v will have an easier time letting air in at 8 psi as compared to a 2 valve doing the same at 8psi. when you get into higher boost 12 psi+ the 4 valve really starts to shine (assuming your motor can handle this) over the 2 valve. the 4 valves are simply more efficient.

ShadowDrake

I'm sure GM has spent a LOT of time on head design on the lsx motors, it's not -all- displacement. Bring your 4.6 2vup to a 5.4, and what do you get? Almost zero HP, but a little extra torque, you're still nowhere near lsx territory even though the displacement is getting close.

97WHITEVENOM

Of course you wouldnt be in LSX territory... you need bigger valves, cams, and intake. It aint just... punch out the motor and your haulin', you have to let the bigger cylinders breath.

radaman

I know one thing, if I lived back in my home town of Atl. My old 02 2v/gt would be a Modular powerhouse getting work done. I could then ride around with a 650rwhp gt 2v whatever...oh yeah, Id do the same with the Mach.

6mustang6

as i said. they did alot of work on the lsx heads. the reason for the bigger puched out 4.6 is to be able to put in larger valves.