aftermarket heads???

[LS2 KLR]

Just curious why we don't have higher flowing heads available? Foxes and LS1s have some pretty good numbers.

stock heads 163/153
VT stage lls 213/193
MPH 2.5s 235/202
MPH stage lll 248/225

With my mods and an extrude honed intake I wouldn't mind higher flowing heads:dontknow: What is it about using higher flowing blower heads for an na application that is a bad idea? I'd just like to get a few more ponies and wasn't sure if I should get alittle more porting done to my vts. And does anyone know how much more power the MPH 2.5s make over the VT stage lls?

 

[CaliLifeStyle]

Go with DOHC cylinder heads and call it a day. It would cost a fortune for the swap but they are the best out there.

 

[hotmustang331]

With FI you would gain ALOT. Jim fitz gained 100RWHP from switching from VT heads (st1s i think) and blower cams, over to MPH heads (3 i think) and MPH blower cams.

 

[Gearbanger 101]

Don't concentrate too much on just over all flow figures alone when looking at Modular heads. Truth be told, 95% of the 4.6’s out there aren’t enough engine to even justify anything more than ported stockers anyway. A 4.6L engine doesn't require a head that supports that much volume, since it’s displacement is considerably smaller than either the Ford 5.0L or GM 5.7L engine. Yes, if you’re building an all out, stroker complete with cams and a hard hitting level of forced induction then yes, you might find yourself maxing out the stock casting, but otherwise, you’ll never see it, nor will you have the need for a higher flowing head. Just because you purchase a head that will flow a larger volume of air, doesn't mean you'll ever see that level of flow, or use it to it's full potential. If that were the case, then it wouldn't make sense for the 5.0L guys to run anything less than AFR 225's on their mild bolt on cars. Volumetric Efficiency is what you should be looking at, not just overall flow figures.

 

[forpit2000gt]

N/A you can only move so much air. more is not always better. With the cams and intake you can benefit from some better flow. The PI haeds are capable, with work, of flowing as good or better than aftermarket heads for pushrod engines.
No need to go to 4v engine setup( to mod would be way to expensive) In a FI application, I would rather have 2v setup.

 

[tjm73]

Just curious why we don't have higher flowing heads available?

Because their isn't enough market to justify the expense of production when the stock heads support as much power as they already do.

Ported stock heads can support over 500 wheel hp. Not very many people run a combo that needs more than the stock heads can support.

 

[Gearbanger 101]

Ported stock heads can support over 500 wheel hp. Not very many people run a combo that needs more than the stock heads can support.

Way to shorten what I just said down to the basics. Sometimes I just type waaaaayyy to much crap to get my point across.