Setting LT1 Valve Lash Cold
Race Director
Joined: May 2006
Posts: 18,756
Likes: 2,589
You set them cold. Google 30-30 valve adjustment. There is a paper by John Hinckley and Duke Williams that covers the 30-30 and LT1 adjustment procedure. It requires you to adjust 2 valves at a time rotating the crankshaft by hand every 90 degrees for 2 rotations. Intake is .016 and exhaust is .023.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
One thing I always wondered about the Hinckley paper is that he states that the service manual calls out for the valves to be set hot and running.......Ummm.....how exactly do you set solid lash running.....? Humor me please.
Jebby
Jebby
Race Director
Joined: May 2006
Posts: 18,756
Likes: 2,589
Have 16 sets of disposable feeler gauges?
Safety Car
Joined: Oct 2004
Posts: 3,926
Likes: 739
From: Youngstown Ohio
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Burning Brakes
Joined: Aug 2007
Posts: 897
Likes: 246
From: Green Valley Ca
Thanks Bob
Race Director
Joined: May 2006
Posts: 18,756
Likes: 2,589
Jebby, could you post the paper that you’re stating about John Hinckley, in reference to mechanical valves are set hot and running. I would like to past that the paper along too Duke Williams who is the other author of LT-1 mechanical valve adjustment paper with John Hinckley.
Thanks Bob
Thanks Bob
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,239
Likes: 9,381
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
I use the 2 valve lash at every 90* for all my solid lifter cams. I just use the manufacturers lash numbers. It works very well.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Make sure that they are all a bit loose before you start the engine. As long as there is "some" clearance, there is no problem with setting them hot (as long as you have a way to deal with the oil splash).
Thread Starter
Drifting
Joined: May 2006
Posts: 1,864
Likes: 148
From: Santa Barbara California
The 30-30 Cam and the LT1 cams are different and have different intake and exhaust clearances. The suggested method for setting the LT1 clearances is to do it warm. I would prefer to set them cold but wanted to know if there is a conversion in order to set them cold.
Race Director
Joined: May 2006
Posts: 18,756
Likes: 2,589
Download the paper it covers the LT1 cam and I gave you the cold settings in post 2 of this thread.