The Stovebolt Site Forums The Shop Area Engine Shop Head bolt Tightening Pattern And Push Rod Clearance

I am looking for the bolt tightening pattern and cold and hot push rod settings for a 1962 Chevy car 235 engine. Is there a Wed Site showing the bolt pattern? Also do I put anything on the head bolts before installing them. Thanks!!! 1-262-392-2989 or mribbich@wi.rr.com

Marv.

Marv,

Here is some information on head-bolt tightening taken from Shop Manuals.

Here is a technique for setting valve lash.

This website will show the tightening pattern and the valve lash for your engine.

I oil the threads and under the tops of the heads before installing before installing the head bolts to allow the bolts to stretch easily under the torque wrench. Tighten them in proper sequence to 30, 60, then 90 pounds. Then, one at a time using the same sequence, back them off 1/4 turn and then torque them down to 100 pounds.

If you want to pre-set the lash cold, set the intake to .008 and the exhaust to .021. That will get you real close to the hot specs and you can fine tune when you get the engine hot. I find it easier doing it this way because it saves time spent reaching over the top of a very hot engine! Most of the time, you'll find that at least half of the valves will not need any adjustment when hot if you pre-set them cold.

http://www.canadianmilitarypattern.com/1960%20235-261%20Engine%20Manual.htm

Matt

Marv, just re-read your post and noticed you have a car 235. I'm pretty sure the '62 car 235's came with hydraulic lifters and the instructions that I gave above are for adjusting the valve lash with solid lifters. Sorry if I created any confusion for you.

Matt

Maybellene is correct - all 1956-1962 car 235 engines had hydraulic lifters.

Sorry about missing the "car" engine.

Adjusted valves as stated in the link, had a few that were making some tapping. Adjusted them until the tapping went away was this the right move? I hear something in the exhaust don't know if it is the muffler or do I one of the valves to tight and is there a way of telling which one is to tight? Seams to me it is idling a little rough what should the idle speed be? Thanks!!!

Marv.

Check the underside of the rocker arm tips where they contact the valve stem. Quite often there is a step worn into the contact face that prevents a good valve adjustment being made. If the rockers are smooth, redo the static valve adjustment procedure. Continuing to tighten the adjusters until the noise goes away is risky business- - - -as the engine warms up the pushrod length grows due to heat and the lifter won't be able to compensate for the extra length if the plunger is adjusted close to bottoming out.
Jerry

Jerry,
Would it be best to adjust them like the link shows and leave them even if they make noise?

Marv.

A noisy hydraulic lifter is a symptom of another problem, usually. Stovebolt hydraulic lifters are notorious for getting an internal air lock that prevents proper adjustment unless a relief groove is ground into the ball end of the pushrod where it intersects the lifter plunger. This situation is caused by the lack of oil flow up the pushrod like on the V8's and later inline sixes. The stovebolt pushrods are solid. There's a tech tip somewhere on how to make the lifter leak a little oil out the top to eliminate the air lock by grinding a shallow groove in the pushrod ball area.
Jerry
.

"There's a tech tip somewhere on how to make the lifter leak a little oil out the top to eliminate the airlock by grinding a shallow groove in the push rod ball area."

Thank you, Pre '68 Dave