Dtownbrown

Curious to see how much power people are making running the 317 heads and how much boost their able to squeeze through them?

I currently have a set on my 408 stroker and So far Iv made 733hp @ 13psi. But now I'm considering upping the boost to 20# and getting in the 900's. My heads aren't ported but are studded and torqued to 90ft lb.

RickyBobby

I am running un-ported 317's. Little different set up though...6.0, 2.3 whipple, 13 lbs boost, 4l80E, 607/672 on Mustang Dyno.

I've been told by a few they are a restriction at my level but have never been given an estimate on hp gain if they were CNC'd.

Dtownbrown

I'd like to know what's the most power that's been pushed with non-ported ones.

_zebra

same here. i've been contemplating running ported 317s on my TVS LS1

5 Liter Eater

Before I swapped heads I ran stock 317's to ~20# and made 880. When I took them off they wouldn't hold water in the chambers for too long (IE: When CC'ing a head) so they needed a valve job. I still have them in the shed. After swapping to All Pro's (and resolving valve float issues) I picked up ~40 RWHP.

Dtownbrown

Nice. I'd be happy with 880.

Mopower2007

I've got CNC'd 317 heads with stock sized stainless valves on an iron block 403. It makes 895 rwhp & 731 rwtq on 20 psi.

APS TT kit with LG turbos.

GOTHAM VETTE

I have ported ones on a 347, with 14.7lbs of boost I'm making 720 rwhp. I run a bunch of HPDE's with the setup so I'm not pushing the setup to much.

PRE-Z06

Our tuner's budget LS stang runs unported 317s as high as 30psi with a single 88mm turbo on 93+meth, through an unlocked glide it has been a best of 5.6@128 in the 1/8.

MawneeC5

I made 609rw on a forged 347 -3cc pistons with some cleaned up 317s thrown on. 14psi falling off to 12 psi with a single TC76 turbo.

MVP'S ZO6

That's moving out for sure! !

JT FRC 00

How was the midrange power with the 317's? I've been contiplating swapping out stock 241's heads with a set of 243's that I have but thinking about the 317's and raising the boost a little. Just not sure what would B better. Raise the compression a tad or drop it a tad and up the boost.

_zebra

in simple terms: more compression for quicker response or more boost for higher power (given the same cylinder pressure).

JoeyG

Same realm of reasoning as Zebra. My UPP twin Vette uses ported 317's on my stock LQ4 shortblock, because they were there. I was originally wanting ported 243/799's for better midrange power at the 1/4 mile tracks. But then again I'd be kicking myself running standing mile events and having to compromise between the increased compression ratio and the higher boost.

_zebra

sorry, it's hard to do an extensive search on an ipod, but you've seen better top-end results on 317s than 243/799s?
i'd be fine losing a little midrange to make up some top end with my TVS

LedfootLarry

Not to thread hijack, but do you have ay pics of the whipple setup ?

mdaniel

You can make big power with an LS1 or LS6 head without much effort. I remember an F-body car running low 8s ten years ago with basic LS6 heads.
The concern becomes keeping the heads nailed down.

_zebra

x2

and remember that yeller C5Z that got the custom 3.3 strapped on a couple years ago? that one seemed fun, too!

breecher_7

My buddy ran a set of cheap ported 317's on his old 364ci. Made 915whp on a eddy current dynojet @7000rpm and 21psi.

Id say they work pretty well.

RickyBobby

It's in a 1973 Camaro...not a vette, sorry.

If you still want to see pics, I can share.



little vid I made .