LS3 head porting
#1
TECH Regular
Thread Starter
iTrader: (9)
Join Date: Dec 2007
Location: Ohio
Posts: 460
Likes: 0
Received 0 Likes
on
0 Posts
LS3 head porting
I have been looking into all the different companies that port LS3/L92 heads recently and they all claim 20-40rwhp gains. Ive googled the hell out of this and im curious how much gain actually comes from the port work compared to the milling. I have a new forged 370 short block set up to turn high rpm and be hit with a 200 hp shot of nitrous. Would head porting be benifical to my motor or should I just have the heads milled down and call it good?
P.s The motor will be running a Patrick g spec'd eps cam. 235/243 .62X/.62X 110+4 LSA
P.s The motor will be running a Patrick g spec'd eps cam. 235/243 .62X/.62X 110+4 LSA
#3
TECH Regular
Thread Starter
iTrader: (9)
Join Date: Dec 2007
Location: Ohio
Posts: 460
Likes: 0
Received 0 Likes
on
0 Posts
I know for sure that Im going to mill the heads .040" with stock LS3 gaskets. My question was wether or not it is worth the money to port the LS3 heads on my high revving(7400rpm) 370 ci motor.
#4
TECH Junkie
iTrader: (28)
An LS3 head has a very large intake valve. With a 4" bore from the LS2 you are limited to how much you can mill the head as well as limited cam selection. Make sure you are aware of this.
A TFS 225cc cathedral port head may be a better choice. Better PtV clearance and it will flow plenty for your little motor. More power in the mid range for sure and a thicker deck to begin with.
A TFS 225cc cathedral port head may be a better choice. Better PtV clearance and it will flow plenty for your little motor. More power in the mid range for sure and a thicker deck to begin with.
#5
TECH Regular
Thread Starter
iTrader: (9)
Join Date: Dec 2007
Location: Ohio
Posts: 460
Likes: 0
Received 0 Likes
on
0 Posts
The motor was originally a LQ4. Its a 4.030 bore now with forged flat tops that have the LS3/L92 Valve reliefs. I already have new LS3 heads, Intake, and head gaskets. I plan on a .040 mill to bump the compression back up to close to 11.0:1. I think with the .040" mill it will be about 10.87:1 which should be decent. I want to get as close to the 500RWHP as possible for this motor before the nitrous, so thats why im asking if the heads need to be ported or not.
#6
TECH Junkie
iTrader: (28)
With 370ci I'd think 500rwhp would be a very optimistic goal.
Every point increase in compression is worth around 3-4% increase in power. You want as much compression as possible.
LS3 intake valve is also 2.16" which is massive even running a hollow style lightweight valve.
Every point increase in compression is worth around 3-4% increase in power. You want as much compression as possible.
LS3 intake valve is also 2.16" which is massive even running a hollow style lightweight valve.
#7
TECH Regular
Thread Starter
iTrader: (9)
Join Date: Dec 2007
Location: Ohio
Posts: 460
Likes: 0
Received 0 Likes
on
0 Posts
The motor is getting a victor jr that has been ported, so maybe that will help it peak a bit higher? What is a realistic number to expect on power?
4.030 iron lq4
Ls3 heads milled .040
Ported victor jr
235/243 .621/.629 110+4
2" primary long tubes
T56
Will the porting be worth the money to get me closer to my power goals or should I have them milled and leave them umported?
How much power is there to be made with porting alone?
4.030 iron lq4
Ls3 heads milled .040
Ported victor jr
235/243 .621/.629 110+4
2" primary long tubes
T56
Will the porting be worth the money to get me closer to my power goals or should I have them milled and leave them umported?
How much power is there to be made with porting alone?