g5x3 112 flycutt?
Drifting
Joined: Feb 2007
Posts: 1,446
Likes: 0
From: Cranford NJ
Race Director
Joined: Aug 2006
Posts: 13,542
Likes: 1
From: Are you fat because you're lazy or lazy because you're fat? San Jose, CA
Cruise-In X Veteran
St. Jude Donor '09
head cc?
It probably depends on what cc you have the heads at. I think stock is 66cc, and often times, to increase the compression, aftermarket heads are milled down to 58cc-64cc. I think the rule of thumb is a .003" mill is a 1cc decrease in cc for LS1 castings.
Can anyone verify?
Go to ls1tech.com and you can find out the specifics of this application.
Can anyone verify?
Go to ls1tech.com and you can find out the specifics of this application.
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
I just had my ported 5.3s milled to 59cc...they took .025" off to acheive that chamber size.
The X3/112 with stock heads/gasket will fit fine w/o cutting, but I believe it's right at the minimum recommended value for safe p/v clearance. (.080" intake, .100" exhaust).
My G5X4/111 right now is around .050" clearance on the intake valve, maybe even a little less.
A little too close for my liking...but I have to flycut it to run the milled heads (and .040" gasket), so although I'll have to cut a little deeper, I will make the clearance acceptable.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Thread Starter
Intermediate
Joined: Aug 2006
Posts: 26
Likes: 0
From: Lawton OK
.005" = 1cc removed is the general rule of thumb.
I just had my ported 5.3s milled to 59cc...they took .025" off to acheive that chamber size.
The X3/112 with stock heads/gasket will fit fine w/o cutting, but I believe it's right at the minimum recommended value for safe p/v clearance. (.080" intake, .100" exhaust).
My G5X4/111 right now is around .050" clearance on the intake valve, maybe even a little less.
A little too close for my liking...but I have to flycut it to run the milled heads (and .040" gasket), so although I'll have to cut a little deeper, I will make the clearance acceptable.
I just had my ported 5.3s milled to 59cc...they took .025" off to acheive that chamber size.
The X3/112 with stock heads/gasket will fit fine w/o cutting, but I believe it's right at the minimum recommended value for safe p/v clearance. (.080" intake, .100" exhaust).
My G5X4/111 right now is around .050" clearance on the intake valve, maybe even a little less.
A little too close for my liking...but I have to flycut it to run the milled heads (and .040" gasket), so although I'll have to cut a little deeper, I will make the clearance acceptable.
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
You want no less than .080" clearance on the intake valve, and no less than .100" clearance on the exhaust. Whether you notch the pistons or not.
Depth of cut can only be determined after you measure your actual clearances and find out if you even need to cut or not.
For example, if you stick the cam in, check the p/v clearance and find you only have .050" actual clearance...you'd want to cut at least a .030" deep notch to achieve a safe clearance.
You don't want to cut if you don't have to, and you don't want to cut any deeper than necessary...all you do is lose compression.
Thread Starter
Intermediate
Joined: Aug 2006
Posts: 26
Likes: 0
From: Lawton OK
how do you check ptov clearance? put clay on the piston and put a soft spring in the head to hold the valve and turn the cranks by hand and see how much clearance you have by measuring the clay?
Racer
Joined: May 2002
Posts: 256
Likes: 1
From: Waukee IA
Reason I went with an X3 on 114. Didn't feel like pulling heads and fly cutting plus the chances of hitting the rev limiter w/o milling on the 112 is a scary thought and possible scary sound of a piston slapping a valve 
