Jriver

GCD1962

First off, do they need adjusting ? Unless there is a clatter or noise from the valve train, chances are everything is in order and doesn't need adjusting. The whole premise of hydraulics is that they don't need periodic adjusting like solid lifters.

rsavage1

I drape the inner fenders with old towels and also tuck them along the top of the exhaust manifolds up against the heads. Start it up, back off each nut one at a time until you can hear it click, tighten until the click goes away and then turn another 1/4 - 1/2 turn. I know that some would turn them further, but I am more comfortable with a 1/4 to 1/2 turn. I work quickly down one side (the valve cover is still on the opposite side. Re do it. and shut it off. Remove towels as the manifold is getting pretty warm. Replace valve cover gasket and reinstall. By then the other side is cool enough to do it.

Bluestripe67

If you insist on playing with the valves, for whatever reason, find one of many YouTube videos that shows the exact correct process. Dennis

Factoid

Frankie the Fink

I've ALWAYS adjusted hydraulic lifters with the engine running....back off till they clatter and tighten down until they just stop...then go 1/4 tighter in increments pausing for 5-8 seconds at each quarter turn to let the lifter stabilize....I usually end at 1 turn from zero lash -- many go less... Hydraulics are pretty forgiving...

Vette5311

MikeM

If they're not making any noise, leave the hood shut and don't screw with it.

AZDoug

I have an old valve cover I cut 8 holes in (using a step drill), large enuf for a socket to fit the rocker arm adj nut to fit.
With gasket and valve cover on, no muss, no fuss, no oily mess, and since i zero lash---turn down to just not clattering plus 1/8 turn, i get no lifter pump up at higher (6000 plus) RPM..
Doug

dcamick

domenic tallarita

Don't forget that the made metal clips that went on the rocker that covered the hole so you wouldn't get a eye full. By the way I adjust to the 1/4 turn also

Dom

R66

If you love your car, you work on the things that affect perfection or just don't seem right.
I also use a cut-out valve cover with the engine running. Frankie is giving you the best info. GM says 1 turn from 0 lash (rockers clattering). I generally don't go past 1/2 turn. When racing, I left them at 1/4 turn as the old school dictated more clearance = higher RPM, but don't know if it works. Never dominated a NHRA class.
Get an old valve cover and drill or modify it to control the oil. Then have at it one side at a time. Keep in mind the Chevy SB is the worst when it comes to cam wear and you may need the modified valve cover again as the cam goes south.
You bought the toy to play with, The more you learn about her the more you will enjoy her, the car that is.

Westlotorn

I will assume you either have a miss or a loud lifter and are trying to fix it.
I have used a piece of cardboard several times over the years to adjust hydraulic lifters if needed.
If memory serves me I cut it 6" high and about 24" long which gave me enough to fold it to fit just inside the valve cover opening and the oil would splash on the cardboard and run back into the head.
It is a one time use thing, use it an toss it.
It works to help minimize the oil splash mess. Now I have extra old valve covers to use which do a better job.
If you want to run the lifters at the top of the travel they make performance lifters which have a much sturdier retention spring instead of the spring clip used on OEM lifters.
If the lifter piston is tapping on the retainer spring it can pop the spring out. I have found these springs in the oil pan before.

Robert61

I'm with Factoid on this one. Can't imagine why anyone would want adjust them running.

Frankie the Fink

With cut off valve covers (Westlotron-style) or oil diffusers (see link below); running adjustment is a non-issue and you get to adjust on an engine with hot oil pumping up the lifters and its easier to compensate for differences in valving or spring strength or other subtle variations in how they operate... I use the oil diffusers personally...(of course you'll have to reach into your pocket for six dollars):

https://www.summitracing.com/parts/oes-25050/overview/

tbarb

I agree with you and factoid only for me it's one turn down past zero clearance. I don't drive to create valve float conditions.

Robert61

Frankie the Fink

domenic tallarita

I think it was Frankie that said they would be accurate adjusted warm. He is right. Does it matter for grandma if they were done cold? NO. There is a specific hydrauilic bleed off. The lifter gets oil pressure from the hole down about half way of the lifter body. That pumps the lifter enough to stay on the cam ramp. Now the lifter has to have a bleed off so it doesn't hold the valve open. As all know , the valve cools when touching the seat in the head. Problem is that the bleed off is not all the same on all lifters. To much will cause a lifter noise and to little will hold the valve open enough to burn it. I do all of mine cold according to the Chevy manual, but when I raced and wanted everything perfect I did them hot with the clips over the hole so I wouldn't have to change shirts. Face it, we are not as **** as we were, or, are we more ****? I have a lifter bleed down contraption that I built and will not patent. I use it on all aircraft lifters that are hydraulic. I have sent new ones back with a red tag stating that they are not airworthy. Car lifters are 100% better than aircraft.... The main reason for aircraft (gas) engine failure is camshaft failure. Continental Aircraft admitted to that. The check ball on a lifter can move off the spring and cause a valve to screw the cam up. But, if you want them perfect (which doesn't matter much) do them hot and running. Now the racing stock in the 60's said to adjust them to 0, not 3/4 or more as the manual says.
Again the argument is that if you adjust them 1 turn, the oil pressure will pump the lifter and give it a bit more lift!
You decide, We drive these beauties with respect 12!@#$%.

Dom

Chuck Gongloff

If you insist on adjusting them, AND if you insist on adjusting them with the engine running... you NEED these clips.

Without them, you'll have oil squirting everywhere.... Don't ask me how I know this.

You'll also have oil draining/oozing down onto the exhaust manifolds... and down the side of the block... You can create a real oily mess real quick.