[Hotrodjohn71]

Let me first preface this with the note that my 326 block does indeed have the oil gallery plug installed behind the other plug on the rear passenger side of the block for lubrication of the passenger side lifter bank.

I have a freshly rebuilt 1965 pontiac 326 with all stock components including new stock cam, lifters rockers etc. I took it to a shop here that's been in business for many decades and had him assemble it to a short block after all necessary machine work.

I pre-lubed the engine and broke in the cam using Driven BR30 break in oil revving it between 2000-2500 for about 20 mins, then drained oil, changed filter and reapplied new Driven oil for the 500 mile break in.

I believe the shop checked all the rocker arms when they serviced the heads so after checking the pushrods for bends or damaged ball ends, I assembled it and it runs fabulously.

I have noticed a little more rocker arm clicking than I would expect from a fresh motor. It's not loud in the car but I can hear it from the engine compartment.

I tightened the rocker stud nuts to about 25+ pounds.

So 2 questions. It this to be considered normal sound from an old motor, or can I shim with washers of a certain thickness, perhaps .100" under the nut but above the rocker to locate them a little lower to take up the slack and let the hydraulic lifters self adjust accordingly?

[leeklm]

I would start with a stethoscope or a piece of 1/2 fuel hose or garden hose and try to pinpoint where the sound is coming from. I.e. only from under one valve cover or both sides?

Recently helped a friend with a 389 build using hyd roller lifters and otherwise stock valve train and that engine is dead silent- almost too quiet!!

Sent from my SM-G965U using Tapatalk

[Hotrodjohn71]

Thank you Leekim,
It's really just the passenger side which I know would almost surely make folks think that the inner gallery plug was missing but it's not, and oil psi is great.

It's not loud but definitely audible and annoying.

[Vengeance Race Engines]

Originally Posted by Hotrodjohn71

Thank you Leekim,
It's really just the passenger side which I know would almost surely make folks think that the inner gallery plug was missing but it's not, and oil psi is great.

It's not loud but definitely audible and annoying.

Yes, you can shim it a bit to preload the lifter a little more and help quiet it down. Non adjustable valvetrains rely on pushrod length for preload, with a given lifter height and rocker arm. If any of the rockers have a more wear than others, it will affect preload a bit, or just enough to possibly make a noise. However .100" shim seems excessive. You would need to know the current amount of preload, as to not bottom out the lifter and wipe a lobe.

[Formulas]

After untold miles of service and wear and then ground on seats and valves at rebuild the old non adjustable rocker arm system can be a crap shoot for good results

I would just get straight 7/16 studs, if on a budget the cheaper ones from paul spotts for pontiac and lock nuts or poly locks

After that if they are not quite then a bad lifter or lobe

[tom s]

Double check if the builder used correct 65-66 rockers!MANY dont know better and use the 67 and later rockers which are not the same.Tom

[Hotrodjohn71]

Thank you, I will research and try to find out what the difference between those rocker arms is. I've also noticed that about three different lengths of pushrods are offered for the 65 Pontiac 326.

[Hotrodjohn71]

I have a little update. I checked the lash on my lifter preload.
They're all averaging about 1 and 3/4 turns past zero Lash. This of course being checked on the base lobe of the cam on every one.
I have read that 1/4 to 1/2 past zero lash is appropriate.
Being that mine are sitting so low, could my ticking sound problem be that there's too much engagement into the lifter plunger rather than what I had originally thought which was not enough?

[steve25]

Yes!
You could have the plunger too far compressed into the lifter and your hearing bottom out especially once oil temp comes up and the plunger is not supported by the oil as well at low rpm.

There should never be a need to use more then 3/4s of a turn passed zero lash if nothing is waring abnomally or you have no push Rods that have bent or pressed in studs that have pulled up.

I would run the motor and loosen up each rocker adjustment one at a time until the rocker clicks good and loud, and not just a faint tick.

I would let this take place for 10 seconds to assure that the lifter pumps up all the way and then do the adjustment of 3/4s of a turn passed being silent.

[Hotrodjohn71]

Thank you. I think you've helped me solve this issue.
I've seen the self locking Chevy rocker nuts discussed alot.
Will those nuts hold tight to the studs with a torque equivalent to the 20 pounds torque that the original Pontiac nuts torqued down to?

[steve25]

Self locking Chevy type. Nuts are only good for one adjustment and after that they will likely not hold.
You should get polylocks at this point,

[Hotrodjohn71]

Ok, thank you.
I have a question about these press-in studs. My studs have a little nub on the top.
I've read that the nub can cause the poly lock to come loose so some guys change the studs to flat top ARP or just simply grind the nub off so the poly lock wedges against a flat surface.
Which method would you recommend and by looking at the picture, can you suggest which length poly locks to get?

[Kenth]

There i nothing wrong using CSB rocker nuts, i have used the same set for 25+ years.
How often do you need to adjust the rockers?
I checked my adjustment one time in 25 years and it was perfectly fine.
Also, 1 turn on 3/8-24 threads i about .040" and the plunger in a standard hydraulic lifter is .120" from top to bottom. It is preferred to have the plunger halfway down in lifter so 1 turn preload will work just fine.
I know my engine has survived for 25+ years with 1 turn down from "clattering" rockers.

If you want silent lifters/rockers at all engine temperatures avoid the 20W50 syrup and use want Pontiac engineers recommends. 10W30 will flow fast to the lubricating places in the engine opposed to the syrup.

FWIW

[tom s]

did you confirm you have the correct rockers?Post a pic of the valve end.Tom