I currently have a nice 5.4 3V ready to go to the builder. A 4.6 4V just came across my path. Till it is all said and done both motors will cost about the same when I'm done. The main advantage the 4.6 is already done and buttoned up, complete from TB to the pan. It has 98 Cobra cams and some serious head work including larger valves.

I know the extra 50 cubes is worth a lot, but so is the 4v over 3v. All things being equal dollar wise, which motor should I go with?

My goal is to beat my 4.0 V6 current best of 12.03 @ 117, I'd like to get thier N/A if possible, my power adder of choice for now is Nitrous. I have had a Pro Charger, a turbo and currently a 100 shot. I like the juice for the simplicity especially when tuning so that's how the build (either motor) will play out.

Thoughts?

 

Both have readily available parts, put what's easier to get in the car. Either way you have to buy a new ECU, either way you have a lot of work. The 4v probably weighs less doesn't it? Are you swapping the guts of either or just running as is? If it's the latter I would chose the 4v personally.

 

The 4v has has everything but the ECU, I'm not sure which one to use. The 5.4 can use an 06 ECU, my car is an 06. The 4v also has the wiring harness, other than the computer it is ready to run.

 

im curious to see how this topic develops, cause i have plans to either do a terminator build, or get an aluminator shortblock and keep the stock heads and throw on my supercharger of choice. I have other options but i wont get into it right now as these plans are being saved for spring time so things may or may not change.

what are these stock 3v heads rated to? when do they develop a HP restriction?
im trying to do a nice build without changing the heads if i dont have to, but if i do then straight to livernois i will go.

 

What 4v? The Mach 1 aluminum block or the Terminator iron block? We know the 5.4 is iron. Either way, I would lean towards the 4.6 since it has cams and head work unless the 5.4 has something comparable.

 

[quote=classix_stang289;5783436]im curious to see how this topic develops, cause i have plans to either do a terminator build, or get an aluminator shortblock and keep the stock heads and throw on my supercharger of choice. I have other options but i wont get into it right now as these plans are being saved for spring time so things may or may not change.

what are these stock 3v heads rated to? when do they develop a HP restriction?
im trying to do a nice build without changing the heads if i dont have to, but if i do then straight to livernois i will go.[/quot




Uh well...if you do a search you will find that twin turbo'd 3V motors can push upwards of 1000 rwhp in extreme builds. Remember the Chevykillers engine build???? Had it survived it would have been an outstanding example of what they a capable of.

 

then there's always the "there's no replacement for displacement" argument...

 

Im a fan of the 4V.... but I am biased. You can make some killer power and with the right parts really rev the snot out of them

 

I always have been too going back to 70's Lotus days...

However, Ford's 'new' 3V has only 50% of the cam drag of the 4V, but has less than 25% of the airflow reduction compared to the 4V (I say less than 25% because the 3V's singular ex valve is much bigger than one of the two ex valves in each cyl of the 4V).

In theory, the 3V should be able to put out more HP/Torque per cylinder...

I think the only reason to go back to the 4 Cam/4V, is with Ford's new iVCT where you can really tweak the in & ex cam timing/overlap at different rpm ranges. That's pretty cool!

 

How about a 5.4L 4V?

 

I was just going to say sell both for a 5.4 4v and a whipple

 

rb6 if the 4v is forged already, go that route. Throw a big shot of nitrous on it and let it eat.

 

This is all about what you want to do with the car. If your goals are just to get into the 11s like you stated, you can do that (and much more) with the 4.6L, which is going to be 70ish pounds lighter than the iron 5.4L block. Seventy pounds is nothing to sneeze at.