Big boost with rectangular port heads? Step inside
#1
Big boost with rectangular port heads? Step inside
So i closed my season on a lean #7 cylinder, which made me tear into my engine sooner then expected. On inspection of my heads i noticed little cracks on the head between the valves. Im positive they werent there before installation. Im also switching around intake setup and have the chance to go to a rectangular port head. Ive searched for about a week now seeing no one really put a rectangular port head to the test of high boost. Many that see 10-12 psi, but im looking at 24-28 range. So who has put a LS3, LSA, LS9 head to the test? Would notice a power gain in the lower at lower boost levels with these heads? Or should i stick with my 317s?
Background on the car: 370, GT55-94, 25 psi average, E85, 1/2" ARP studs, LS9 gaskets . Current heads are hand hogged 317s that held up to over 75 20-28 psi passes, and probably hundreds of street pulls.
Background on the car: 370, GT55-94, 25 psi average, E85, 1/2" ARP studs, LS9 gaskets . Current heads are hand hogged 317s that held up to over 75 20-28 psi passes, and probably hundreds of street pulls.
#2
FormerVendor
iTrader: (7)
The LSA and LS9 head would be much better than the 317s. Since you are setup for it, Id rock the LS9 because of the 1/2 head bolts. It will take a little machine work, but youll be happy with them.
We run 19-22 psi on the ZR1s with out issue and getting pretty crazy with the tuneup and water temps ( 25-27* timing and AFRs in the 13s on a road course)
Id stay FAR away from the 821 or 823 LS3 castings.
We run 19-22 psi on the ZR1s with out issue and getting pretty crazy with the tuneup and water temps ( 25-27* timing and AFRs in the 13s on a road course)
Id stay FAR away from the 821 or 823 LS3 castings.
#3
The LSA and LS9 head would be much better than the 317s. Since you are setup for it, Id rock the LS9 because of the 1/2 head bolts. It will take a little machine work, but youll be happy with them.
We run 19-22 psi on the ZR1s with out issue and getting pretty crazy with the tuneup and water temps ( 25-27* timing and AFRs in the 13s on a road course)
Id stay FAR away from the 821 or 823 LS3 castings.
We run 19-22 psi on the ZR1s with out issue and getting pretty crazy with the tuneup and water temps ( 25-27* timing and AFRs in the 13s on a road course)
Id stay FAR away from the 821 or 823 LS3 castings.
#4
TECH Fanatic
iTrader: (9)
The LSA and LS9 head would be much better than the 317s. Since you are setup for it, Id rock the LS9 because of the 1/2 head bolts. It will take a little machine work, but youll be happy with them.
We run 19-22 psi on the ZR1s with out issue and getting pretty crazy with the tuneup and water temps ( 25-27* timing and AFRs in the 13s on a road course)
Id stay FAR away from the 821 or 823 LS3 castings.
We run 19-22 psi on the ZR1s with out issue and getting pretty crazy with the tuneup and water temps ( 25-27* timing and AFRs in the 13s on a road course)
Id stay FAR away from the 821 or 823 LS3 castings.
Trending Topics
#19
TECH Enthusiast
iTrader: (4)
Join Date: Apr 2008
Location: Home town Clive,IA current town FORT BENNING GEORGIA
Posts: 525
Likes: 0
Received 0 Likes
on
0 Posts
From the old beat to death L92 head threads seems like if you try and machine them to run 1/2" studs they break super easy under a decent amount of boost. I'm running standard diameter ARP studs and will see how far i can push my L92's with the GT-88