VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Rocker arm adjustment

I had to replace the rocker arm assemblies and some push rods. I have reviewed the service manual for adjustment, but it is either not very well explained, or I can't read very well. Could someone tell me how to properly adjust each rocker arm. Does the valve being adjusted need to be in a certain position to make the correct adjustment. I get the screw down the bolt and lock it into position with the nut part, but was concerned about what spring tension needed to be applied.

Any help would be appreciated.

Thanks

Craig

The valve you are adjusting must be closed-stem all the way up.Then loosen screw till you feel just a little free play.The free play will be about .008" on the intakes-the tall stems and .014" on the exhausts-the angled stems.I prefer to do it with the engine running.Then the feeler gauge is slid back and forth and valve adjusted.When there is just a slight drag on the feeler (when valve hits the top) adjustment is correct.Try it after you set them with the engine off.

I generally set all the valves by turning the engine over by hand and with the valve lash adjusted loose, usually 2 or 3 thousandths loose , this is set when the valve is completely closed. This is a starting place to get the engine where it will run without missing or firing thru an partially open valve, then after the engine is running.....Do the following.

I believe the manual tells you to get the engine up to operating temperature, (not just the coolant warm) but the entire engine, which is necessary to account for heat expansion of the pushrods, rockers and valves....then with the engine running at a slow idle use a feeler gauge to set the valve lash, which is the gap when the valve is closed between the valve stem and the face of the rocker, you should be able to slip the correct feeler gauge between the rocker and valve stem, if you can't the lash is too close, if you can slip the feeler gauge that is a size larger in the gap the valve is too loose, if it is too tight unlock the lock nut and loosen off the adjustment screw with a screw driver and then lock the nut down. If you are useing a boxend wrench and a screwdriver you have to coordinate the boxend the screwdriver with the up and down action of the valve and rocker.

One more thing if the face of the rocker is worn so much that there is an impression of the valve stem you will eat up your feeler gauge, at least I did....if that happens the face of the rocker arm must be dressed (ground) till it is smooth.

Hydraulic valves are easier, the gap is 0, that means you set them to where there is no gap or lash, the mechanisum of the hydraulic lifter makes up the correct lash. I would say that is the main reason for having Hydraulic lifters.
Hope this gets you to a starting place.

This is the way that The Wacky One does it! Pretty much like the Chev-Nut does it......

Are you supposed to run the engine with the valve cover off?

Thanks

Craig

Yes, and if you don't 'race' the engine it will not get oil all over the place. While adjusting the valves the engine should be run as slow as possible. After setting the valves then adjust the air/fuel mixture screw and finish by setting the idle. All of these values are specified in the repair manual that matches your car.

Also, don't wear a white shirt while performing the above procedure! Ha ha!

don't get your tounge between your teeth while adjusting valves on a running engine!

Ok, I have one more novice level question. When the rocker asm's are not installed, shouldn't all of the valves be fully closed? I see various heights among the valves with respect to the amount of spring tension that appears to be applied. I wondered if valves ever get stuck open....

Thanks

Craig

Yes, all intakes should be the same height-all exhausts the same.......you have some valves sticking in the guides - the original cause of the broken rocker arms.--

What to do?!?

If it were mine I would try freeing the valves.To do this a solvent must be applied to the stem - just above the guide.Can't be applied to top of valve as valve seal will prevent it from running down to guide.After the stem is soaked a few days a soft hammer can be used to tap the top of the valve stem.As the valve moves up and down slightly apply more solvent - if valves fail to free up removal of the head will be necessary.

What to use for solvent_Marvel Mystery oil may help.PB Blaster- a penetrating oil in a spray can will also be good for a "start".

If you are lucky and the valves do free-up pour some of the M.M.O. thru the carb. as soon as the engine starts-this will lubricate the stems at the lower end of the guide.Also add a pint to the gas.

This sticking problem may have been caused by old gas,Drain the tank and put in fresh gas.

Thanks for the advice. I had already found the sticking valves. I had 4 in the front. I had also already poured on some mmo, recovered the engine to let it soak in. It seemed that most of it ran onto the floor....I will let you know if I make any progress. Thanks for the help.

I will also do the gas tank suggestion. I think I read that somewhere else, too.

Craig