Setting valve lash on 120

clint s

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I have a very small tick when the engine is running so light that if the cover is down you have to strain to hear it. It varies with Rpm and seems to go away after about 2000 to 2500 rpm. If you take the oil fill cap off and listen it does not seem to get louder. Could this be just normal valve noise? I have to replace the valve cover gasket so I am going to lash the valves just to be sure. My manual says to get the rotor pointing to #1 with the points open and then gives the valves to adjust and then go to #4 on rotor with points open and do the others. Am I looking for up and down movement on the push rod or spinning them between my fingers to set 0 lash. I have always spun them between my fingers and tightened them until resistance is felt on cars. Another Big thing is that in one part of my service manual it says 1 full turn past 0 lash and in another part it says 3/4 turn. Which is it?Also engine warm or cold in the book it says cold. I know you can do it with the engine running, but I would rather try to do it this way because of less mess and less work. Any help would be appreciated. Clint (sorry for the long post)
 

clint s

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Re: Setting valve lash on 120

I forgot it is a 120. The 153 CI GMC engine. Without serching for the registration I think it is an 82.
 

Bondo

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Re: Setting valve lash on 120

While I prefer the Running Method,.......

Doing it Your way is Fine,......

As for the # of Turns to tighten them,......

They're Hydraulic,..... About Anywhere between 1/2, and 1,+ 1/2 is Close Enough,.......

I tighten Mine to about 3/4 turn after Quite......Using the Running Method of course......
 

clint s

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Re: Setting valve lash on 120

They're Hydraulic,..... About Anywhere between 1/2, and 1,+ 1/2 is Close Enough,.......

Thanks for the reply, but I want to make sure I get what you said. Are you saying anywhere between 1/2 and 1 1/2 would be close enough? I think you are trying to say anywhere between 1/2 and 1 is close enough. What you wrote is a little confusing. Thanks again Clint
Engine warm or cold?
 

Bondo

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Re: Setting valve lash on 120

Ayuh,........ A Warm motor Clint,.....

And you're Right,...... That's abit misleading,....
It'll Run in that range,+ the lifters would be nearly solids by the 1,+ 1/2 turns,.... But I don't think they'll bottom out til you get nearer to 2 full turns........

Like I said,..... I run them at 3/4 turn after Quite.........
 

clint s

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Re: Setting valve lash on 120

Well I set them today and I used the engine running method. I turned them 1 turn past quiet. Would it be wise to back them off a 1/4 turn or will I be ok leaving them the way they are. What would happen if I left them at 1 turn and they were too tight. If I should turn them back could I just go back and loosen them up with the engine off 1/4 turn and be set. Also it is tough to get my engine up to temp when running off the muffs because my well water temp is about 45 degrees any problem with that. The engine feels warm but the water temp is not over 100*. BTW the ticking is coming from #1 exhaust valve and did not go away when I lashed the valve. I even went up to 1.5 turns to see if it got better. Were to go from here, should I just let it be because it is not bad and has been noisy for as long as I have had the boat.
 

clint s

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Re: Setting valve lash on 120

What a small world I just looked at your profile. I live just down the road from you in Parish, exit 33 off 81. I used to fish for salmon in the Chaumont river, and i make a few trips up to the St. Lawrence every year. Clint
 

Bondo

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Re: Setting valve lash on 120

Ayuh,........

I gotta think that you might be loosing #1 exhaust,..... But it might go Along Time before it's Really an Issue,.......
I'd probably just Run It til it gets Worse......

And a Small world it Is,........
My Love is from Sandy Pond,+ still has Family there.....
We boat from Chaumont Bay down that far occasionally,.....
I usually trailer up to the St Lawrence,....
 

clint s

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Re: Setting valve lash on 120

Should I keep it at 1 full turn or back it off to 3/4. I have heard if they are too tight it could cause them to fail earlier.
 

Don S

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Re: Setting valve lash on 120

The OEM service manual calls out 1 full turn, so it is not to tight. No need to back off now that you have them set.
 

clint s

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Re: Setting valve lash on 120

In my service manual were it describes the lashing procedure it says 1 full turn, in the spec section in the back it says 3/4 turn that is were my confusion is coming from. Same manual 2 different settings. It is a Seloc manual.
 

Don S

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Re: Setting valve lash on 120

Like I said, the OEM Service Manual..................

Not the cheap aftermarket Seloc and Clymers manuals with lots of mistakes.
 

clint s

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Re: Setting valve lash on 120

It really is not that bad of a tick you cannot really hear it with the cover down. I had to replace the valvecover gasket so I said what the heck I will try to adjust the valves. It has made this noise since I have owned it for 6 plus years putting 15 to 25 hours a year on it. I will just live with it until it heads south. If 1 turn is what the manual says I will keep it at that. I adjusted it both ways engine running and not running with the same results. Thanks all Clint.
 
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