best way to adjust rocker arms on allum. heads

[hotrod_991]

I have a 350 bored .40 over with allum floteck heads, roads lifters mutha thumper cam and .50 push rods and sportsman roller tip rockers and I cant seem to keep the rockers in adjustment. Does anyone have any tips on adjusting them and maybe keepin em in adjustment other than a set of stud gurdles that I plan on getting when the money allows me to. Any help is apreciated thanks.

[rjs53]

For a small block Chevy (or any engine with a firing order of 18436572) you can set the valves by turning the engine over just two times. Bring the engine up to #1 firing (both #1 valves closed and the timing mark aligned with zero on the timing tab) and adjust as follows: exhaust valves 1,3,4,8 and intake valves 1,2,5,7 bring engine up to #6 firing(rotate engine one complete revolution) and adjust as follows: exhaust valves 2,5,6,7 and intake valves 3,4,6,8.

Method #2:
This is the one I use and it goes like this: when the intake valve on a cylinder has opened fully and is almost closed, adjust the exhaust valve of that same cylinder. When the exhaust valve starts to open, adjust the intake valve of that same cylinder. This method takes a little longer but it works very well. your rockers should have a jam nut to help keep them tight for proper adjustment also i would recommend doing this with the motor warm

[hotrod_991]

no jam nut but do have the poly locks with the allen style hole. Ill try the first method first and see how that works out. I read in a speedway catalog about a way to do it by rotating the motor 90 degrees between each two adjustements not sure whta the method is called tho. That was how i did it last time.

Also they way I was taught was the roll the rod between my thumb and index finger as im tightning the rocker till I feel it start to drag then 1/2 to 3/4 turn and lock em down. Does that sound about right?

[gchemist]

I do it with the engine running! I recently did it to my ZZ4. Roller cam engines are zero lash.

[cableguy0]

Method #2 that rjs posted is the best most accurate way to adjust the valves on any engine regardless of make. It works on any valvetrain setup. Theres not a need for a doing a running engine adjustment. If the valves are adjusted properly they wont need a running adjustment.

[rjs53]

sorry couldnt think of the correct term POLY LOCKS my brain some times gets a jam nut regardles your rockers shouldnt be loosening up.

[Marv D]

Originally Posted by cableguy0

Method #2 that rjs posted is the best most accurate way to adjust the valves on any engine regardless of make. It works on any valvetrain setup. Theres not a need for a doing a running engine adjustment. If the valves are adjusted properly they wont need a running adjustment.

DITTO! you can set preload on the lifters on the engine stand this way and never look back! Unless something wears unexpectedly, the hydraulic lifter will take care of it.

Here's the same thing said with a few more details
http://www.small-block-chevy.com/cb_6.htm

One suggestion, with a poly lock you have it made. Loosen the inside allen head lock, set the lifter on the heal of the lobe as described above and run the adjusting nut down with your FINGERS to zero lash. This works ideal because you can't go past zero lash with your fingers. Then add your 1/4 or 1/3 turn with a wrench. Another suggestion,,, don't get stupid with the inside allen head lock. Over tightening the lock is just good reason to break a rocker stud. It doesn't need anything more than a good T-handle allen wrench will supply. Too many guys want to use the wrench and JAM the crap out of the lock with a twist of the adjusting nut. That puts a big stress on the rocker stud at the base of the lock nut. If you tighten it that way, are putting a lot of stress on the studs with stiff springs,,,, a broken rocker surd should be expected. I'm not saying they can be left 'loose',,, but just don't get crazy with the lock

[hotrod_991]

thanks to everyone for thier input I am going to give it a try tomarrow morning if I have enough tools here at the house as I dont want to drive it with the loose rockers for fear of damage. motor has about 240 miles on it so far so dont want to risk anything. Ill do the finger to zero lash option. Would the stud gurdles be worth the money for a weekend toy? I plan on running it on the strip from time to time but mostly just raisin hell around town.

[rjs53]

how high RPM do you plan on running what kind of lift does your cam have? If it's mainly for street i would use ARP screw in studs and call it good thats just me. I geuss the girdles are cheap insurance. you will need tall valve covers though

[hotrod_991]

I have tall valve covers already, and I plan on turning close to 6000 when i shift. my cam has .500 lift.

[bigsnookmaster]

You don't need stud girdles. They stabilize the valvetrain and keep the rocker shafts from flexing. On a .500 lift they wouldn't be required.

[Marv D]

Agree,, if it were a solid with a buttload of spring pressure designed for the .50 lift rule and 8000rpm,,, sure a stud girdle is cheap insurance. But not a hydraulic with only .5 lift and 6000rpm.... I bet you only have 95 to 110 pounds of seat pressure and probably not over 250 on the nose. Save the $ for something else.

[hotrod_991]

ok thanks for the advise gentlemen. im going to atteck the rockers here in a few hours and ill post if I have any issues.