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Rocker arm adjustment

 
KorvetteKev
I love my Chevy Chevette!
Posts: 2
Joined: 03/12
Posted: 03/11/12 02:25 PM

I just adjusted the rocker arms on my BBC after installing new pushrods. I followed the method that Comp Cams advises. However, after adjusting all of the rocker arms, I noticed that some were still a little loose (the ones that were not compressing a valve spring). They weren't too loose, there was no play in the pushrod, but I didn't think I should be able to wiggle them by hand. I fired up the motor, and didn't hear any clatter. I gave them another 1/8 turn just to feel better, and ran the motor again, and they were still a little loose.

Is it normal to be able to wiggle the rocker arms a little after they are adjusted, or should they be unmoveable?

I'm running Comp hydraulic lifters with a XE268H cam. The motor is a late 70's vintage 454.  

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 03/11/12 04:09 PM

Korvettekev welcome to the forum:

You did not pump up or fill the lifters with oil. That is a No-No today!

Assuming you have all the pushrods in their correct places.  There are 8 long and 8 short pushrods.............Short push rods measure 8.820" Long 9.250".

Start with the #1 cylinder. Disarm the ignition.Remove #1 spark plug and with the aid of a helper have them tap the starter until #1 is at TDC. Back off the exhaust rocker arm until there is play in the pushrod. Now as you slowly adjust the rocker arm with that pushrod between your two fingers adjust the R/Arm until you feel a slight drag on the pushrod. Now you can adjust the R/Arm 1/8 to 1/4 turn down thats it. Then go to the next lifter-R/Arm and adjust it in the same manner. Continue until you have completed all eight cylinders....

Then go to the next Cylinder and do the same procedure. It is more time consuming this way but you have the feel for adjusting.

YES you will have some rocker arms that will as you say wiggle... LOL....as you go onto adjusting the other lifter-R/Arm.........
Thanks,
Bob  

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 03/14/12 03:02 PM

A none believer!  

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KorvetteKev
I love my Chevy Chevette!
Posts: 2
Joined: 03/12
Posted: 03/14/12 09:50 PM

I did the adjustment cylinder by cylinder just like that (except I gave the rocker arm nut a half-turn after the end play was taken up), but even after running it for a while I can still grab the rocker arms and wiggle them back and forth a bit.  I'm used to working with non-adjustable rocker arm setups on mopars, that use a common bar for the rockers arms to ride on, where there would be no lateral movement possible. I don't hear any noise when running the motor, so I guess a little wiggle is OK.  

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 03/15/12 09:07 AM

The non adjustable rocker arms are just that a PITA. I know I had FE BBF's back in the day. We put shims under the rocker arm petistals to run a slightly bigger cam, so we didn't have to buy adjustable rocker arms.

The same for the MOPAR guys also. My buddy back in the day had a 1967 GTX with a 383. The push-rods stopped spinning and actually wore thru the cups. Back then Chrysler had a 7 year 70,000 mile warranty. I can't tell you how many times they replaced the shafts. We finally shimmed the Pedistals. The service manager wanted to know what we did. The Mopar engineers couldn't figure this out I doubt it. I don't think anyone cared back then....
Bob  

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