1964 Lifter adjustment

[Geoff B.]

I'm getting some noise that I am pretty sure is coming from under the valve covers. I have heard that the solid lifters on the L76 do need to be adjusted on occasion. The shop manual I have shows a pretty simple procedure of backing off the rocker arm nut with engine idling and then slowly tightening in 1/4 turn increments until 1 full turn is made. Is that really all there is to it? No need to use a feeler guage to set the lash?

[Dan H.]

Re: 1964 Lifter adjustment

Geoff, if you have an L76, it's a solid lifter engine, needs .030 gap, not tightened down, that sounds like the hydraulic setting proceedure. See the Archives for proper setting of the L76 motor.
Dan

[Geoff B.]

Re: 1964 Lifter adjustment

Thanks for the response Dan. I'm getting that procedure I referenced from the 1963 Shop Manual and it's in Section 6-6 for setting valve lash on solid lifters. I did notice that some of the posts I found have a much more detailed procedure, so it's bit confusing. I was wondering if it's because you use the procedure from the manual with the engine running and you use the other procedure with a feeler guage with the engine not running.

[Duke W.]

Re: 1964 Lifter adjustment

1964s are not 1963s. You need a 1964 Shop Manual Supplement.

If you have a 1964 L-76 with the OE 30-30 cam you have mechanical, not hydraulic lifters.

The adjustment procedure (lastest 09-23-2008 revision) is at this link:

http://www.lbfun.com/warehouse/tech_...n/SBvlvadj.pdf

The next time someone asks, which will be the zillionth time, you get to give the answer.

Duke

[Stuart F.]

Re: 1964 Lifter adjustment

Ah shucks. Let him at least try to set them with the engine running. Everyone should have that fun experience at least once in their life time.. Really important you follow Duke's advice and procedure on setting valves on your 64 L-76. Throw out those .030" -.030" clearance specs too. We'd hate to have you mess up that jewel.

One question: Are you sure you have an original cam?? I'd try to determine that first before proceeding to pull those valve covers.

Stu Fox

[Geoff B.]

Re: 1964 Lifter adjustment

Thanks for the help and advice! I do not know for sure it has the original cam. Is there any way to tell without taking everything apart?

[Duke W.]

Re: 1964 Lifter adjustment

No, but if you remove a couple of rocker arms you can measure gross lobe lift with a dial indicator lined up with the pushrod. Both inlet and exhaust are .323" nominal.

Before you do the valve adjustment, check the ignition system - spark plugs and plug wires, points, dwell, initial timing, centrifugal and vacuum advance. The specs are in the '64 Shop Manual Supplement.

After checking that the ignition system is functioning properly and adjusting the valves, you must go through the idle speed/mixture adjustment procedure, and set the idle speed at 900-1000.

All of the above is part of a normal tuneup that was called out every 12,000 miles.

A lot of guys forget that these vintage engines need periodic checks of these items because modern engines don't need anything except filter changes and a set of spark plugs every blue moon. Also after decades, multiple owners and no service/repair records, most guys don't have a baseline on when these components were last checked, repaired or replaced, and they can't figure out why there engine runs poorly.

Get a baseline on the engine's current condition and go from there.

Duke

[Geoff B.]

Re: 1964 Lifter adjustment

Thanks again for all of the help.

[Carl N.]

Re: 1964 Lifter adjustment

I agree, everyone should always try adjusting with the engine running

will give you a reason to clean up the engine bay if you have decent oil pressure and do not have a set of clips for the rocker arms (if anyone even makes them anymore)

[Stuart F.]

Re: 1964 Lifter adjustment

Carl;

I have the clips which you refer to, but trust me, they are not much help. They keep the oil from squirting on the fender panels, but still allow it to build up in the head and spill over down the side of the engine and on to the exhaust manifolds. The worst headache I ever had in my life came from trying to adjust valves in a garage with the door open, oh around 1956 or so. I have never used them since and that includes 5 years of very active campaigning Chevy V8's in racing.

Stu Fox

[Clem Z.]

Re: 1964 Lifter adjustment

since most lash specs are in "hot" setting the easy and clean way to set the lash is to run the engine and then set the lash both valves on one cylinder. let the engine set over night,check the lash on that cylinder cold and now you will know what to set the other cylinders cold.

[Duke W.]

Re: 1964 Lifter adjustment

Been there, done that. Cast iron head and block, steel pushrod and valve - the thermal expansion rates are nearly the same, so there is no signficant lash change hot and idling versus stone cold.

When run hard the exhaust clearance will close up somewhat, but I don't know of a way to check valve clearance at WOT, peak revs. That's why exhaust lobes usually have taller clearance ramps - more allowance for clearance reduction so the valve doesn't hang open.

Aluminum head and/or block or both either pushrod or OHC is a different story.

Duke