SBC valve adjustment question.

[junker39]

I've gone thru the rotation and have all tightened the rockers so the pushrods won't spin with my fingers. How much addition tightening do I do the rockers?? It's been a while since I've done a Chevy. I usually just put the oil splash deals on the rockers and get the valves quiet, while running and do one more full turn. But, on this '92 C20, there's too much junk that's got to be moved/removed, to get the covers off and on, I need to do it this other way. And, get it right the first time. My remember is telling me 1½ turns. Is that correct? Thanks a lot for the help.

 

[26Troadster]

if running i loosen till it tics, tighten till quite then go 1/4 turn. if new motor i set top dead center, tighten till i can barely turn push rod with fingers. rotate motor 360º and get the other half of the valves, i prefer to do fresh motors with intake off. after 20 to 30 min. break in i do readjust on fresh motors as in a running motor. hope that helps.

 

[junker39]

Thanks 26. It's an old motor with a few miles. I really can't do it running without a big hassle.

 

[Yankee Transplant]

Ive got it wrote down stuck in a book in the shop on doing it intake on certain cylinders and exhaust on other ones . I have to read it and do it .. I dont do enough to know it by heart .. if you dont get it figured out I'll go dig up the paper on it ..

 

[sgtpontiac]

1/4 to 1/2 turn is normally good on a used motor...

Thanks 26. It's an old motor with a few miles. I really can't do it running without a big hassle.

If you can barely turn pushrod with valve fully closed it should be good (at bottom of lobe)....1/4 turn is what I use but some go the 1/2 turn....if that helps...

 

[Yankee Transplant]

This is the new method to me that I used on my engine that I have not started yet . I was told it works All of my parts are new on the engine

put the engine on #1 TDC adjust #1-2-5-7 intake and #1-3-4-8 exhaust spin the pushrod with your fingers till it gets hard to spin. then turn 3/4 turn

then turn crank 1 full turn you will be on #6 TDC at this point
you adjust intake #3-4-6-8 and #2-5-6-7 on the exhaust side ..
I have only done this one time and Im not ready to start my engine yet to see how I done ,,, I have always turned to each cylinder till the slack is out then start and adjust 3/4 after rattle is out ,, but that really gets oil all over your engine and floor These instructions I got from a race car man so if anyone sees a problem in this let me know cause I havnt tested it yet .

 

[sgtpontiac]

YT....yeah there are all sorts of methods....

I've tried them all but settled back to the basics...when the other valve on that cylinder starts to open, I adjust the other....then turn it till the valve I adjusted starts to lift and adjust the other...then move to the next cylinder...just seems faster to me and I'm not guessing about which I've done and which I haven't.......personal preference I guess.... (plus the fact that my memory is going...LOL..

 

[Yankee Transplant]

sgt that seems a lot easy-er to remember ,, I shot oil over my fenders on a ford before trying to adjust it running ,, that turned into a mess .but it worked

 

[sgtpontiac]

And it works well on fresh or used motors...

No guesswork involved...you do one cylinder at a time and done....like I said, just seems faster and easier to me....also...much less messy... lol

 

[Old Iron]

I don't like the term "till it's hard or can't turn the pushrod".
Depends on who you are and how strong your fingers are, you can actually have them too tight too start with.
Engine not running, I roll the engine until the cylinder I'm working at is at top dead center.
Loosen the intake and exhaust rocker till you can hear a tick with your fingers then tighten till the tick is gone and then another 1/2 a turn.

 

[sgtpontiac]

OI....

Won't argue the point on the pushrod....some might have muscle bound mitts...lol...I just got into the habit of doing it that way...tighten the nut till the rocker puts some drag on the rod as you spin it, but I do understand the jiggle..click method.....a few variables but all in all most of the methods listed will work fairly well...just hate all the oil cleanup on the running methods and when I was in the shop doing this stuff for a living, I wanted to get it done, then mount all the factory crap back on before I started it....so perfected my way of doing it so it was done and out the door.....too many AC brackets and crap to deal with....

 

[Dr Crankenstein]

Many ways to skin a cat.

I like to do one bank, then the other... turn #1 to overlap, lash both valves and move to the next. 1-3-5-7-2-8-4-6 keeps turning to a minimum... of course you need to pull the plugs and have a bar on the... crank.

.

 

[sgtpontiac]

did you say "bar next to the bank"....

Many ways to skin a cat.

I like to do one bank, then the other... turn #1 to overlap, lash both valves and move to the next. 1-3-5-7-2-8-4-6 keeps turning to a minimum... of course you need to pull the plugs and have a bar on the... crank.

.

We got one of those here....

 

[Old Iron]

I agree. There are a bunch of ways to accomplish the same thing.

 

[junker39]

Thanks for all the input guys. The method I use is:
put #1 @TDC on firing stroke. Mark bottom pulley in quarters. I mean, a mark about every 90 degrees. Do the valves on #1. With the plugs out, it's easy to turn the engine with a rachet/socket on alternator pulley nut. I turn engine 90 degrees, which puts #8 at TDC on firing stroke. Continue on thru the firing order 90 degrees at a time and doing the valves on each cylinder. I always spin it over a few times and double check. I went ahead and did these using a half turn after push rod snug up. Thanks everyone for the help.

 

[Bamamav]

I do like Sarge, one cylinder at a time, tighten 1/2 turn after pushrod quits turning between my fingers. If it's a performance engine that I don't mind adjusting more often, I only go 1/4 turn. Never had a problem not being enough. Have done it many times with the plugs in place, too. Easy to hear if you have a valve open too much that way, too.