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rocker adjustment

 
xpbxwrecked
I love my Chevy Chevette!
Posts: 1
Joined: 12/07
Posted: 12/30/07 09:53 PM

what is the best way to adjust the rockers in an 89 305 camaro?  

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skinnyz
V-6 Camaros rule!
Posts: 49
Joined: 12/07
Posted: 12/31/07 03:48 PM

Copy and paste this link into your internet browser. You should end up with a page out of a book by David Vizard. That should get you going.
http://books.google.com/books?id=G2kUibvRUo8C&pg=PA127&lpg=PA127&dq=rocker+adjustment+small+block+chevy&source=web&ots=miqDkPAYLn&sig=4nDLepcWUFcZLzi2fj5gf800Dyg#PPA127,M1  

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55Guy
Big Block power for the win
Posts: 895
Joined: 08/07
Posted: 01/02/08 01:30 PM

Just remember, half a turn of lifter preload on the hydraulic cam!  

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sds-oe
V-6 Camaros rule!
Posts: 61
Joined: 12/07
Posted: 01/02/08 03:11 PM

roll the engine clockwise with a wrench until #1 is in the fire position, note the #1  rocker arm movement as you turn it to be sure it's the #1 mark on the balancer. if the rockers move when your bringing the timing mark up, it's on #6.   when you have #1 at TDC, you can adjust :

   exhaust #1, #3, #4 & #8

   intake #1, #2, #5 & #7

now rotate the engine one revolution until the timing mark is on TDC for #6, now adjust:

    exhaust #2, #5, #6 & #7

    intake #3, #4, #6 & #8

as you tighten the rocker nut, roll the pushrod with your fingers. at the first feel of drag, note nut position and tighten 3/4 of a turn more. this will give it the recomended preload for GM lifters. some lifter makers want a different preload, always follow their specs.  

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skinnyz
V-6 Camaros rule!
Posts: 49
Joined: 12/07
Posted: 01/02/08 09:00 PM

Just remember that this particular method is not effective with long duration camshafts. The lifter may not be fully on the base circle. The method posted through the link above will ensure that each lifter is where its supposed to be. It takes more time, but proper results are guaranteed.  

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skinnyz
V-6 Camaros rule!
Posts: 49
Joined: 12/07
Posted: 01/03/08 06:29 PM

If you have a stock or near stock cam then sds-oe method is the easiest.
Some engine builders insist that adjusting the lifters with the engine running is the best way. Messy but 100% effective regardless of cam profile.  

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sds-oe
V-6 Camaros rule!
Posts: 61
Joined: 12/07
Posted: 01/04/08 09:54 AM

the method i outlined was also in the assembly instructions for my ZZ502. with a duration of 224 (i) and 234 (e) @ .050, GM must feel this is acceptable. i was leery of it at first, but the valvetrain is working fine. i don't think i would use this method on a longer duration cam.  

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skinnyz
V-6 Camaros rule!
Posts: 49
Joined: 12/07
Posted: 01/04/08 01:58 PM

The method you describe is also in the GM factory manual for the 68 Chevelle I used to own. You're right in that a cam any bigger than your 502 (must be nice!) would probably require the more involved adjustment procedure.  

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skinnyz
V-6 Camaros rule!
Posts: 49
Joined: 12/07
Posted: 01/04/08 02:04 PM

So to answer xpbxwrecked question, the method that sds-oe describes will give you satisfactory results. Truth be told, I've used the same method on a cam with 268 duration and .488" lift with no trouble although I've been working the other methods so that when (and if) the bigger came comes along, I'll be able to adjust it properly.  

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