i have a 1970 chevy sb 350 and i need to set the valve lash what is the proper method and where do i start? everything is stock!
Just read this again last light. The motor should be hot an normalized before you start. With one valve cover off clean the cylinder head of all old cork gasket residue lay a new gasket on the head and screw the valve cover bolts through the gasket into the head a few threads. There are companies who sell neat little clips that slide on the push-rod end of the rocker arm to reduce the leakage of oil from the push-rods through the ends of the rocker arms. We're going to hear all sorts of whining and disagreement here but Chevrolet hydraulic valve lifters must be adjusted with the engine running. It's written in a factory overhaul book. The oil pressure from the oil pump has to adequately pump-up the hydraulic valve lifters so you can get proper adjustment. Using 3/8 a deep well socket and a long extension, loosen counter clockwise the center rocker-arm nut slowly till you hear the rocker arm clatter. There's two trains of thought how and why the center not should be adjusted. GM says to *very slowly turn the center nut till the clatter disappears. Slowely continue turning the center nut 3/4 more turn clockwise. William Tyler Grumpy Jenkins (Chevrolet race engine builder) always said to turn the center nut to stop the clatter plus 1/8 of a turn more. He did this so the plungers inside the lifters were extended nearly all the way out. This was done to reduce hydraulic lifter pump-up and valve float at high RPM. For the detractors who don't think this is correct, pull the valve covers off a 265, 283, 327 or a 350 with hydraulic lifters after the engine has been off for 30 minutes. You will see every rocker arm is holding the valves in the closed position. It's impossible to adjust the valves with the engine off.
Woah, woah! You didn't say exactly what 350 you have - do you have a hydraulic lifter cam in it or is it a solid lifter cam? You cannot preload a solid lifter, and doing that with the engine running ain't that good of an idea. You need to get into the ballpark of having the proper preload in the first place in order to even do the final adjustment with an engine running, anyway. Verify what kind of lifter you have before you proceed. For a newb and for a stock engine, you really can't go wrong with the method below - it includes video assistance to help with the visual. I've adjusted hydraulic lifters on a 305 the non-running way, and on a running like the previous post mentioned, for a 350 with a performance cam. Let me tell you, even with the clips, you will make a very big mess adjusting that engine running, plus you need to be painfully careful of doing something dumb, like putting your paws near the running belts - something I wouldn't expect a newbie to feel comfortable doing. Save risking your hands for when you set the timing!
I truthfully have repaired alot of Chevy engines in my time. I continually adjusted them chilly while i became into development the motor or reinstalling products....much less muss and fuss and much less oil in each single place. The GM instruction manual says ( and that i've got been doing this for years ) is with the engine in the #a million firing place ( it is set via putting your hands on the #1valve because of the fact the mark on the damper comes close to the O mark on the crankcase front conceal. If the valves are actually not shifting then the engine is in the #a million firing place. If the valves flow because of the fact the mark comes as much as the timing tab then it incredibly is in the #6 firing place, and may be became over a million extra time to attain the #a million place.) as basically desperate, right here valves may be adjusted. V8- Exhaust- a million, 3, 4, 8 V8- intake- a million, 2, 5, 7 back out the adjusting nut ( 5/8's socket ) till lash is felt ( flow or spin the push rod...in case you could flow it up or down or spin it truly..it incredibly is loose ) while play has been bumped off, turn adjusting nut in a million finished turn ( to middle lifter plunger ) Use basically slightly chalk to mark which valves you have adjusted to maintain music ...desire I helped and sorry for the long dissertation.
