blackbetty

any one ever hear of some one swaping a 4v head onto the 04-08 4.6?

NGM

Yes.. It can be done. My tuner keeps trying to get me to do it...

blackbetty

i know it can be done....im just thinking about doing it more and more...i got getting head on my mind....i mean heads...ha

i was looking at cams and then i was like hell why not go 4v...easy way to get some power....thinking more and more towards h/c/i before i go turbo...

got a write up handy?


btw have you heard people running paxton style s/c's....? i always figured the only thing that would make it not work would would be the massive motor driven fan...but with that gone due to electric fans i cant see why a 99-04 sohc s/c kit wouldnt work, just looking at power adders....goal is about 500 at the rear....not a hard task on a 4v with a power adder ha

obusnizzle

the Mach1 heads are 4V, later incarnation of the C head casting, Cobra intake cams and Navi exhaust cams. It requires the 4V manifold to work. Use the Aviator top end instead, it will flow well into 7000 rpm..problem being that the up high numbers are not cop acetic with the bottom end.

kaboom10

You can get a lot of flow out of some good ported 3v heads. I've been thinking of going 4v on my 02 2v but with all of what has to be changed I'm pretty much gonna go 3v. I was told from the beginning to not do it but I know it's possible. I was told to go get a complete 4v engine to start with and was advised to just put forced induction on it. The IMRC setup only wants to open the secondary ports above 3000 rpm though that can be changed. This brings about tuning issues like setting up a carb that's too big for the application. You make your own decision but this was what I've been told.

blackbetty

a carb??? what are you talking about

and im a 4.6 so 3v heads are not worth it...

kaboom10

I was using it as an example. If you have any inlet system that's too big for an application the air loses velocity when opened quickly and you get a bog or even a backfire. The IMRC is set to open at higher velocities so that this doesn't occur. Yes there are 4v 4.6s out there but they're for a larger engined vehicle. Why do you think they put them on a 5.4? Also will the valve(s) hit the pistons and what is the compression ratio going to be?

obusnizzle

a good set of 3V heads WITH professionally done porting can match the flow rate of a comperable set of 4V heads.

obusnizzle

wrong. The 4V 4.6L has been around since 1993 and it wasnt in a truck. The 4V 4.6L was meant for performance applications. The 5.4L 32V truck was put in the SUV because, well the 2V 5.4L sucks. Putting 4V heads on a 2V block..valves will not hit the pistons as the combustion chamber on a 4V is larger than 2V. If you want a high revving, barn burner, blow their doors off at the dyno 4V motor, go Aviator.

blackbetty

im just thinking of a head swap and the only one id consider is the dohc 4v heads....prob be cheaper then the 3v with porting...

and im thinking the cobra intake would be better to use no? as the aviator is shorter runners so tq will suffer....sure high will make me need a cowl but whatever...a hood swap is not a bad thing right?