BIGWILYT

What heads are you guys using and what type of gains are you seeing?

ace32x

using my stock heads and had them cnc ported by AI, no numbers on gains yet

Ballbearingturbo

I saw 30-40 wheel with my ported heads.

K B Vettin

i bought the LPE ported heads and had a 30-40 gain also.

ZBADESTZ@Straightline

PRC ported heads

sammy burks

You got 30 to 40 with just ported heads.

Ballbearingturbo

Yes.

old motorhead

At what boost level did you guys see these gains? And what other mods did you have?

FastMatt2

One of you ZR1 guys should try out the new TFS LS3 255 heads, did wonders for my CTS-v. My V put down 679 rwhp threw a auto with a ZR1 (LS9 stock) cam with them. I shaved mine down to 64cc befor installing them.

K B Vettin

cam, pulley's, injectors, headers, CAI, lpe snout running 16.8psi

K B Vettin

i had a zr1 friend try to put ported LS3 heads on and they didn't work due to alternator placement and valve covers. not saying they can't work but would not be a driect fit.

old motorhead

Did you cut/mill the heads any to increase the compression ratio? I'm assuming ported stock LS9 heads with stock LS9 head gaskets?

K B Vettin

correct, ported stock ls9 heads with stock gaskets. here are the details of my heads.

Chamber volume: 69.5
9.0:1 Compression on stock LS9 or LSA engine


Minimum of 4.00 bore size recommended with this cylinder head.

Flow numbers are measured on 4.065 bore

LPE CNC L92 LS3 Flow Specs
Intake valve lift / Exhaust valve lift
.200 - 158 cfm / .200 - 116 cfm
.300 - 230 cfm / .300 - 161 cfm
.400 - 282 cfm / .400 - 201 cfm
.450 - 302 cfm / .450 - 213 cfm
.500 - 322 cfm / .500 - 220 cfm
.550 - 340 cfm / .550 - 226 cfm
.600 - 350 cfm / .600 - 231 cfm
.650 - 358 cfm / .650 - 234 cfm
.700 - 344 cfm / .700 - 237 cfm


Lingenfelter CNC machining of the LS9 heads also includes machining the intake manifold locating bosses on the LS9 heads to allow LS3 and L92 intake manifolds to be bolted to the heads without an interference problem.

Competition Cams 26926-16 springs with Lingenfelter Titanium retainers XX04190-0016 on LS9 heads
Installed height: 1.830
Spring pressure: 135 psi @ 1.830 / 480 psi @ 1.150
Coil bind: 1.100
Max lift: .680

old motorhead

Are you using a bigger than stock cam?

sammy burks

I do not think the LS3 heads will work on the LS9 because of the the head bolts diamater on the ls9.

K B Vettin

yes i am.

here is the link to my build thread. since then i've upgraded to the LG radiator and mgw shifter
http://forums.corvetteforum.com/c6-c...scle-cars.html