Setting valve lash?
Thread Starter
Burning Brakes
Joined: Mar 2004
Posts: 816
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From: Finland
Setting valve lash?
Haynes manual gives basics for the procedure - guess it is ok to follow that. But they have no info on precs. My is 396 BB, with mechanical cam and crane gold race roller rockers. Any advice+
I did the seach and found 2 topics that were close and gave some help but any more advice would be appreciated!!!
I did the seach and found 2 topics that were close and gave some help but any more advice would be appreciated!!!
Senior Member since 1492
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From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Thread Starter
Burning Brakes
Joined: Mar 2004
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From: Finland
Originally Posted by Jughead
Any opinions on right lash spec?
Senior Member since 1492
Joined: Aug 2000
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From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Originally Posted by Vesa
Any opinions on right lash spec?
You'll open a whole can of worms with that question.
I think it depends on your cam manufactuer. Mine was listed as 0.022, I've seen people post lower here on the forum. I did have it looser at 0.026-0.028 during assembly and break-in.
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
Follow the cam manufacters recomendations on valve lash. You can usually go a couple of thousandths either way of the recomendations. I would not stray to far from them. I got my procedure for valve lash from the GM service manual.
Thread Starter
Burning Brakes
Joined: Mar 2004
Posts: 816
Likes: 1
From: Finland
Originally Posted by Gordonm
Follow the cam manufacters recomendations on valve lash. You can usually go a couple of thousandths either way of the recomendations. I would not stray to far from them. I got my procedure for valve lash from the GM service manual.
Burning Brakes
Joined: Oct 2004
Posts: 984
Likes: 23
From: Florence SC
valve adjustment
Here's how we adjust valves on our super truck, small and big blocks should be the same; Just as the exhaust valve starts to open, adjust the intake valve (on the same cylinder), when the intake valve is almost closed adjust the exhaust valve (on the same cylinder). I would use the manufacturers recomended lash requirements.
Race Director
Joined: May 2004
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Originally Posted by bracketshark
Here's how we adjust valves on our super truck, small and big blocks should be the same; Just as the exhaust valve starts to open, adjust the intake valve (on the same cylinder), when the intake valve is almost closed adjust the exhaust valve (on the same cylinder). I would use the manufacturers recomended lash requirements.
I figured it must be wrong when I read that post with the mathematical
way to do it......which I will most certainly never remember because I don't do it often enough.
One winter and all that is forgotten
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Race Director
Joined: Dec 1999
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From: Forked River NJ
That is going to be kind of tricky not knowing what you have. What is it set at now. Most cams are either in the .024-.028 range or the tighter lash is around .014 to .016 range. Check to see what you have on a couple of the valves and compare them all. You should have an idea of what it should be by that.
Thread Starter
Burning Brakes
Joined: Mar 2004
Posts: 816
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From: Finland
Originally Posted by Gordonm
That is going to be kind of tricky not knowing what you have. What is it set at now. Most cams are either in the .024-.028 range or the tighter lash is around .014 to .016 range. Check to see what you have on a couple of the valves and compare them all. You should have an idea of what it should be by that.
After reading all sources of info I think I will go with:
Compression stroke at
TDC #1 - 8E, 2I
90 deg. - 4E, 1I
180 deg. - 3E, 8I
270 deg. - 6E, 4I
0 deg. - 5E, 3I
90 deg. - 7E, 6I
180 deg. - 2E, 5I
270 deg. - 1E, 7I
...because I have no clue on my cam profile and this should be safe even with very long ramps as well...
Here is the whole thread where I got that info:
http://forums.corvetteforum.com/show...ing+valve+lash
Senior Member since 1492
Joined: Aug 2000
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From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Thread Starter
Burning Brakes
Joined: Mar 2004
Posts: 816
Likes: 1
From: Finland
Ok - last night I did some work. The engine was totally cold (it was raining and I did not wanna drive on wet street and mess my vette). Most of the valves vere between 0.2 and 0.24 maybe 4-5 were out of that range - maybe 0.04 out - so I did adjust them. Also I noted the intakes were closer the 0.2 and exhausts closer the 0.24 so I followed that and set all intakes somewhere close 0.21 and exhausts somewhere close 0.225.
First impression is that the idle is a bit more stable...
Later today I will check some of them with hot engine to see if there is any difference and a need to readjust.
Anybodu having experience if and how much they normally differ (hot vs cold engine).
First impression is that the idle is a bit more stable...
Later today I will check some of them with hot engine to see if there is any difference and a need to readjust.
Anybodu having experience if and how much they normally differ (hot vs cold engine).
