Tuffnut

Just wondering this winter if there is anything I need to do on the valve train for adjustment. Approx. 2000 miles after the rebuild. Slight tick on cold start up. Goes quiet when it gets warmer. Flat tappet cam. New rockers OEM style. Not rollers. Everything was new, new cam, tappets, push rods, valves, rockers, springs. Its 1975 350 with #5 heads on it. Engine runs real well. No issues. Just want to be proactive.
Thanks

Oldsmaniac

Was the lifter preload checked? There is a chance your pushrods are too short. There isn't any adjustment on the stock Olds valve train...

Sugar Bear

Are you rather certain it isn't an exhaust leak?

Tuffnut

Yes they checked it, I know they ordered new pushrods for the proper length. It only sounds like one cylinder. I don't what the preload was measured at?
What should it be and how do you measure it? Is there another way to test?
Thanks

Tuffnut

Thanks Sugar Bear, I will check that as well. Easy check, Thornton manifolds with gaskets. I will double check.

olds 307 and 403

I have found sometimes with stock rockers, they torque down improperly. Go through them if no exhaust leak is found.

Tuffnut

Thanks Olds 307... what should the torque be? Cold or hot or doesn't matter? Valve position matter, closed?

olds 307 and 403

The spec is 25 ft/lbs. I torque them in pairs, you can rotate it by hand and double check the adjustment.

classicmuscle442

Better to catch it early, using zinc in oil? Would pull apart and see what's up, could be a soft tip or pocket in rocker.

Tuffnut

Thanks Chris, I'm using Lucas Hot Rod & Classic Car 10/W30 oil with high zinc. Will check it out....

Tuffnut

I found a loose bolt on the one manifolds. Tightened it up. I think I will pull the valve covers anyways as one is leaking. I did some research on my bill from the rebuilder and had forgot they installed comp kit 1441 roller tip rockers and set of comp push rods 7948. Without running the engine I should be able to check the preload on each lifter with the valve seated. Keep track of the adjustment turn and rotate the push rod. They mention the pushrod starts to get tight and another half turn for proper adjustment. Some people say a full turn. It’s been 3000 miles since the rebuild and I haven’t checked them. Thoughts?

olds 307 and 403

It can be tricky with the intake on, I would go a 1/4 turn to start. Go too much and bent pushrods with poor running can happen.

Fun71

Many people have warned against using the nuts that come in the Comp kit as supposedly they can work loose. I followed that recommendation and used Mr Gasket poly locks on mine.

Tuffnut

Thanks for the tips guys. I will check it out. I don't want to touch much or adjust as it is running great. Just a slight tick when cold on start up. Possible just one valve or like I said I found a manifold bolt loose as well. Doesn't hurt to check when I have I have time this winter.

oddball

The noise is most likely an exhaust leak. I like to use a length of rubber tube (say, 3' or so), sick one end in my ear and move the other end around to isolate the noise. I find that better than the mechanic stethoscope.
Adjusting valves is a fine time honored tradition. I'd say go for it as it's a good thing to learn and pretty simple. Just need to keep track of what you're doing. Slightly too tight can hang a valve open which will just make it run poorly. Slightly too loose will make it rattle. Go too far either way and parts can break. But here, "slightly" means 1/4 to 1/2 turn, which is pretty easy to control when doing this.
There's no need to do a maintenance adjustment on hydraulic lifters - only solid lifters need to be checked and adjusted.


The pinch nuts that come with that kit are terrible, but doesn't mean you have to replace them. If using the pinch nuts, then go 1/2-ish turn past where the rocker just becomes seated. I prefer to jiggle the pushrod up and down rather than twist, but it all works.
With polylocks, you loosen the center set screw, set the lash (generally 1/2 turn past seated), get the set screw somewhat tightened down, then tighten the nut with the socket to really lock it in place. Just tightening the set screw does not lock the nut.
It's also easier for the pinch nuts to clear under stock valve covers than polylocks.

gs72

I like this guys method. I have used it several times and they come out perfect each time. And you don’t have to do it with the engine running and making a mess.

Tuffnut

It's funny I watched this video last night....What a great way to adjust them from scratch

oldcutlass

What a waste of time.
Why not do it right the first time. Read this
How to Adjust Valve Lash Using the EOIC Method (hotrod.com)

Inline

I recon there has been a fair amount of deals when using the Comp roller-tip kit, where their pushrods self-destroys by mushing either end of ball.
Worth a check if your onto it.

EDIT: Looked up and your part-number turns to Hi-tech pushrod line of theirs; theyve been their lowly magnum pushrods which been destroyed.

deadeyejedi

This is the method i used when i put my 455 together . im using the comp cam roller tip rockers and it worked perfect i haven't had to touch them going on 10,000 miles.

oddball

You can do the valves in whatever order you want, just make sure the lifter is on the base circle. Some methods are faster than others, but can be harder to keep track of what's done and what's not.