CRG Discussion Forum
Camaro Research Group Discussion => Mild Modifications => Topic started by: mopar346 on December 11, 2010, 03:14:00 AM
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I was wondering if anyone had a new or different way to accurately adjust the rocker arms with hydraulic lifters. I would prefer to adjust them on the engine stand before I install the engine as oppose to doing it in the truck and getting oil on everything (yes I have oil clips and can modify old valve covers to minize it). Let me know how you do it.
Thanks in advance, Kevin
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Forgot, crane roller tip 1.52 rockers, studs and guide plates, comp extreme energy stock style roller lifters in a 93-96 SB. If it matters it has 492 heads.
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Being a short duration cam, and also a hydraulic, you can simply rotate the crank until each piston is at TDC (firing stroke of course) and tighten it's rockers there. 18436572 is the GM firing order for you Mopar guys! ;D
An easy way is to rotate the pushrod between your index finger and thumb while tightening the rocker nut down until the clearance has been taken up and you are unable to rotate the pushrod. (Make sure that the pushrod is located properly in the seat of the lifter.) Stop tightening, then give a 1/2 or 3/4 turn clockwise of preload and lock the rocker nut there. (I hope you are using posi-locks or brand new GM sourced crimped locking nuts. Used OE lock nuts are not recomended by me -from experience.)
Some people prefer 1/4 turn, some 1/2, 3/4 or even a whole turn of preload. It really doesn't matter and if you like, go to the cam supplier and see what they recomend.
There is a tiny difference between each preference in rocker geometry and even duration, but it's splitting hairs and not really worth the consideration of deciding which is best for this application.
Personally, I like 3/4. :)
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For you Chevy guys, thats the same firing order for a Mopar. I grow up on Chevys, my first car was a 69 Z, in 83 at age 17 my garage build motor dynoed at 428 HP at the gators. I have use the drag method before with good results, I use to set them at 1/4 turn preload because someone once told me it would make it turn up faster. I really think if your in the plunger there really is no diffference between 1/4 and 3/4. I have locker nuts as well. In your view this is the best way to set them up on the stand. I usually prime the engine first and rotate it several times to make sure the lifters are pumped up.
Thanks again, Kevin
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Being a short duration cam, and also a hydraulic, you can simply rotate the crank until each piston is at TDC (firing stroke of course) and tighten it's rockers there. 18436572 is the GM firing order for you Mopar guys! ;D
An easy way is to rotate the pushrod between your index finger and thumb while tightening the rocker nut down until the clearance has been taken up and you are unable to rotate the pushrod. (Make sure that the pushrod is located properly in the seat of the lifter.) Stop tightening, then give a 1/2 or 3/4 turn clockwise of preload and lock the rocker nut there. (I hope you are using posi-locks or brand new GM sourced crimped locking nuts. Used OE lock nuts are not recomended by me -from experience.)
Some people prefer 1/4 turn, some 1/2, 3/4 or even a whole turn of preload. It really doesn't matter and if you like, go to the cam supplier and see what they recomend.
There is a tiny difference between each preference in rocker geometry and even duration, but it's splitting hairs and not really worth the consideration of deciding which is best for this application.
Personally, I like 3/4. :)
Not a bad method but I would change one part: You tighten the nut untill the pushrod has no more slack loose "up and down" movement. You want to just remove all the up and down slack and then go a 1/2 turn (or what ever) more. Telling newbies to crank down on a rocker nut untill the pushrod stops turning will have the adjustment too tight 9 times out of 10. A well lubricated valve train will spin quite easily at zero lash (and beyond) so it isn't the best way to advise a beginner IMO.
-Mark.
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Well, not you would have any way of knowing but----with 7 out of 8 ASEs at one time (4 before I graduated high school-yes I graduated on time), 26 years in the car business on the fixed ops side and going on 30 years of building cars, I may have passed the newbie stage. Not to mention a 2600 sft shop for my toys and right at 40 cars, its just been awhile since I built a Chevy and have never built a roller motor, so I like to ask and learn before I make mistakes. I was just originally wondering if there might be a more precise way of using a dial indicator to establish the depth of the plunger at full extent and at the bottom of their movement and setting it .090 from the full relaxed position OR some other method I had not heard of.
Thanks, Kevin
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I usually prime the engine first and rotate it several times to make sure the lifters are pumped up.
That really isn't necessary - the spring (#9) under the plunger (#7) will push the pushrod seat (#2) up to full extension, where it needs to be at zero lash with the rocker nut backed off before you make the turn-down adjustment.
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And to think of all the time I have wasted over the years soaking new lifters in oil. ???
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I had the intake off, so it was very easy to see when it began to detent into the plunger, from there I went 3/4 turn. Everything seem to function and move properly when I rotated the engine. The lifter spring will hold against the rocker at TDC, but wont against the valve spring as I rotate. With any luck I will fire it tomorrow so I should be able to hear if anything if out.
Thanks for help, Kevin