hi
i rebuilt my 350 on my 1984 corvette and i want to ajust the valve before i put in the car....my no 1 is on tdc....someone says ajust a few one and after you rotate 1 complete turn to ajust the others one.... but if you make a complete turn you go back at the same place.....no

 

Proper procedure for doing stock Corvette valve adjustment...The only thing I would suggest doing differently, is instead of spinning the push rod to find 0 lash, move it up and down until there is no more movement "or play" to find 0 lash, then give it 1 full turn ..WW

How to adjust stock rockers.....
Bring the engine to TDC on #1 cylinder. Rotor pointing to #1 spark plug wire on the dist. cap and the timing mark on the damper lined up with the zero on the timing tab.
You can now adjust the rockers on:
# 1,3,4,8 exhaust valve and #1,2,5,7 intake valve.
When finished with those turn the engine one revolution on the damper so the timing mark again lines up with the the zero on the timing tab.
You can now adjust the rockers on
#2,5,6,7 exhaust valves and #3,4,6,8 intake valves.
As others have said spin the push rod between your fingers while slowly tightening the rocker arm nut, when you feel it stop spinning tighten the adjusting nut 1 full turn. .

 

 

You got it as detailed by WW7 above.

 

No.. one crank rev is 360° it takes 720° of crank travel to complete one full fireing cycle..

 

I am passing this on to you. It is from Forum member JoeC. I have adjusted Chevy valves for over 30 years and Joe's method is outstanding. Like him, I was always questioning myself if there was too much oil on my fingers and the rod was slipping or my fingers were slipping. Using his method there is no question. I have used this on my LP74211 cam with a lift of over .534 and it works fine. - John

BTW, I tried something a little unconventional on adjusting hydraulic lifters. one thing that always bothered me is the statement "spin the pushrod until resistance is felt" that seems a little too subjective to me. so I tried this: I set "zero" lash with a .0015" feeler gauge while slowly turning the adjusting nut. {place the feeler gauge between the top of the valve stem and the rocker arm.} When I felt the feeler gauge grab, I was fairly confident I was about .001 from zero lash. at that point, I turned the adjusting nut 3/4 turn. I recently read that one turn is equivalent to .040" because of the thread pitch on the threaded rocker arm stud, so 3/4 turn should give you about .030" adjustment. I also read that within a hydraulic lifter there is .060 total plunger movement, and ideally you want to be just about in the middle of that range, or .030 inch. I don't know if I’m out in left field on what I did, but I feel I got a really consistent valve adjustment across the board. if you think you might have a tight cylinder, maybe give this a try - it seemed to work for me...

again, thanks for all your help - take care -

JoeC

 

And don't redo them over and over, the lifter bleeds off on any "tight" (feeling) setting, making you think they need readjustment.

 

thanks to all of you.....

 

I used the method described above when installing my 1.6 RR's and it worked like a champ. Just take your time and double check which ones you're working on. It's probably harder to remove the spark plugs with the stock manifolds then doing the actual valve adjustment.

 

Definitely this. Dont over think it. I also agree with spinning the pushrod as being subjective. I wiggle the rockers until there was no side to side movement, then one full turn, Since you have the valve covers off all you need to make sure the car is at TDC on the fire stroke is to put your hand on the #1 pushrod/valve setup and watch as the balancer comes to 0*. If there is no movement in the valves its at the #1 position. If the valves are moving as the balancer crosses 0*, you are at the #6 firing position. Then follow the adjustment order as detailed by WW.

 

FWIW Factory lifters are one turn (6 flats) from zero lash.
I switched to CompCams lifters, they recommend 1/2 turn (3 flats).

 

I have my own method: Adjust the rocker nuts until they are 0.200" below the top of the rocker stud. That's gets you in the ballpark and you don't have to do any pushrod twisting, engine turning or wondering what cylinder you're on. Then...

Do the final rocker adjustment hot and running. Having a pair of these guys helps keep the oil where it's supposed to be:

 

Ha! Those covers are the bomb!

 

I got a question. When doing the final turn should you see the valvespring compress any??

 

The plunger in the lifter will move down before the spring will compress..When the motors not running there's only a small spriing holding it out....WW
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See that's my problem. I lashed everything up like mentioned above even used the feeler gauge trick. Put it back together and had hard starting and ticking. Took it all back apart and watched closely and seen I had been opening the valve on my final turn. I haven't even attempted to try again in fear of messing my heads up. Needless to say I didn't even get to drive my car this year due to this problem. Have been trying to find someone locally to come give a helping hand.

 

Your question makes me wonder about your experience building engines. Did you rebuild the engine yourself?

 

Something is wrong if you are opening the valve when you make the final 1/2 or 3/4 turn on the nut. If you have done this a couple of times....first twisting the rod...and then followed it up right away using the feeler gauge you are over tightening!

Are you sure that you are doing the correct valve in the correct sequence? Look at the head...the exhaust valve will line up with the exhaust manifold on the side of the head. The cylinders are numbered #1 front drivers side and #2 is front passenger's side. Back to the drivers side #3 is the 2nd cylinder back, #5 is the 3rd and #7 is the rear cylinder on the driver's side.

I would suggest that you go back and back off on all the lock nuts on the rocker arms. Do you have a oil pump priming tool? Is so, pull the distributor and attach the tool to a drill and prime the engine for a good 15-20 minute until you have oil everywhere. This will help fill the lifters if you have over tightened the valves. Then turn the crank by hand using the 5/8 nut in the balancer and place a finger in the #1 cylinder plug hole. Turn the engine by hand until you feel pressure pushing off your finger. Then slowly turn the crank and line up the timing mark with Zero. Now go back to the post by WW7 and adjust the valves. If your using the feeler gauge, place it between the top of the valve stem and the rocker arm. Very slowly tighten the nut as you pull on the gauge. As soon as you feel resistance as your pulling on the gauge....STOP....remove the gauge and then turn the nut 3/4 of a turn. That is all....just the 3/4. Now go to the next valve in the sequence and the same.

 

When you get the #1 cylinder on TDC, you first need to loosen all the nuts on the 8 valves you will be adjusting..This will allow the plungers in the lifters to fully extend all the way out. Then after waiting a few minites you can start adjusting the rockers to 0 lash, then 1 full turn, one at a time...Don't over do it, just take the nut down until the up and down play is gone from the push rod and stop...If your opening valves when your setting the "One full turn", then you must be fully compressing the plunger in the lifter and making it hit bottom, which means your over doing the setting of the 0 lash. Some say 1/2 turn , some say 3/4 turn , but the Factory Service Manual says go 1 full turn after zero lash ,that's what I did when my engine was stock and it worked fine.The objective is to tighten the nut so it places the lifter plunger , half way down, or in the center of it's adjustment range. This is achieved with one full turn after zero lash....WW

 

Thanks John and WW7 for your help. I've had tried everything stated above.
First off yes I'm sure I'm doing them in the right order. I backed them all off to start so I wouldn't forget which ones I've done and even yanked dizzy to prime the engine with tool. Reading what you guys have said I think it obvious I was going to tight to find 0 lash. I'll give it a try again today. Fingers crossed guys. Thanks agains guys.