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1984 Chev 20 PU - SB Rocker Adjust

Posted: Wed Mar 25, 2009 3:49 am
by tunmore
I HAVE A 1984 3/4 TON CHEVY PICK UP. JUST PUT NEW HEADS ON. NO THAT I;M READY TO ADJUST THE ROCKERS, IM HAVIN A LITTLE TROUBLE, I'M TOLD THE BEST WAY TO ADJUST THE ROCKERS IS WITH THE ENGINE WARM AND RUNNING. OK SO I.VE GOT THE ROCKER CLIPS AND CUT UP SOME OLD VALVE COVERS ECT... WITH THE TRUCK BEING LIFTED AND VERY LOUD AND THE OIL ON THE EXHAUST SMOKING IN MY FACE I CANT ADJUST A THING! IS IT REALLY BETTER TO ADJUST WHILE RUNNING? IT DOES HAVE A PERFORMANCE CAM IN IT. THANKS????

Re: SBC ROCKER ADJUSTMENT

Posted: Wed Mar 25, 2009 3:53 am
by wbuxton
Call me. I'll tell you how I doit but I don't want everyone here laughing at a transmission tech giving advice on an engine concern.

Re: SBC ROCKER ADJUSTMENT

Posted: Wed Mar 25, 2009 3:56 am
by Stewart Levy
Best way is to Cut old distributor cap and turn the rotor to the cylinder that you are adjusting . I assume that you are using a Hyd cam and not a Flat tappet. When the rotor points to the cylinder crank the nuts to .002 Lash both ext and Int Move the crank to the next and repeat This is how ive Done them for years and never had a comeback!

You have dipped the lifter is fresh oil and pumped them up?

Re: SBC ROCKER ADJUSTMENT

Posted: Wed Mar 25, 2009 4:09 am
by Tim Martin
Ya that is one good way, I go with zero lash but .oo2 is almost that.

Re: SBC ROCKER ADJUSTMENT

Posted: Wed Mar 25, 2009 5:19 am
by liljoe
I turn the engine to each cylinder tdc and loosen both rockers, tighten till you can not turn the push rod with your fingers, tighten 1/2 turn more. this gets you 0 lash -.050, which is the spec for sbc hyd lifters, this assumes you have oiled and ran engine, which from org post you have. I have done countless of these with no problems.

Re: SBC ROCKER ADJUSTMENT

Posted: Wed Mar 25, 2009 6:25 am
by tunmore
THANKS FOR THE INPUT, I'LL SET THEM THIS EVENING. ILL LET YOU GUYS KNOW HOW IT GOES.

Re: SBC ROCKER ADJUSTMENT

Posted: Wed Mar 25, 2009 6:53 am
by steven kiser
ok, tdc set # 1 turn crank 1/4 turn do #8, crank 1/4 turn #4, do this through the firing order. turning crank 1/4 each time. as a rule i'll make rocker contact and go 3/4 of a turn more on the rocker nut. good luck. that's the way i set em up on the engine stand. never had a problem. basically if it's a 6 cylinder you turn the crank 1/3 of a reveloution. crank turn twice = i cam revolution.

Re: 1984 Chev 20 PU - SB Rocker Adjust

Posted: Mon Aug 17, 2009 10:49 am
by nate23
When the intake valve is open, adjust the exhaust to zero lash and then 3/4ths a turn more. 1/2 a turn if the cam is anything radical or if you've installed 1.6 rockers or both. Repeat on the intake when the exhaust valve is open. Repeat 8 times.

If you are using solid lifters, use a feeler gauge instead of going 3/4s past zero lash.

Re: 1984 Chev 20 PU - SB Rocker Adjust

Posted: Mon Aug 17, 2009 5:14 pm
by sbebenelli
nate23 wrote:When the intake valve is open, adjust the exhaust to zero lash and then 3/4ths a turn more. 1/2 a turn if the cam is anything radical or if you've installed 1.6 rockers or both. Repeat on the intake when the exhaust valve is open. Repeat 8 times.

If you are using solid lifters, use a feeler gauge instead of going 3/4s past zero lash.
This is how I have done it for years. Been awhile since I've needed to though. I remember replacing cams what seemed like weekly on GM's.