rocker arms adjustment

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mopowermatt

mopowermatt
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I am going to be starting up my first 360 this week and my roommate is telling me that he needs to adjust the rocker arms while the car is running is that true and necessary? If I have never done it can I try it alone or should I wait for him to do it. Thanks for the help....
 
hydralic cam w/ adjustable rockers and yes he is a chevy guy. too bad for him.
 
You oughta let it him try. By the way have the video camera powered up. It'll even be funny five years later over a few beers!

don
 
do your self a favor, if you have an old tin valve cover , locate the adjusting screws and cut a slot about an inch and a half wide right above the adj .screws and put it on the motor, it will help keep the oil from spraying every where ,and contain much of the mess.
 
that's what i was thinking. It would be hard holding the wrench and turning a screw with the valvecovers off while the thing is running. I guess he did it with the chevy's


so that's all bullshit or what, or chevy only???
 
there are a few ways to adj. the lifters, I set mine before the oil pump is primed and the lifters are dry ( as in no oil in them) that way you can "feel " the movement of the lifter .....2nd way is to set them to zero lash and then go another 3 / 4 turn on the adj screw... if the lifters have oil in them go slowly and let the lifter bleed down before turning over the motor . it only takes a couple minutes to bleed down.
 
hi, don't set valves with motor running, it's damn near impossible to get a wrench to stay on rocker nut as it moves up and down,you can get your fingers pinched or broken, depends on how lucky you feel. the best and correct way is;, set motor on #1 tdc firing. lossen up adjusternut, back off rocker screw, till you have slack in pushrod. tighten down till no slack or play, then tighen rocker screw 1/4 turn to set preload. hold screw ,and tighten nut. turn motor 90 degrees to # 8, and repeat the same. by going through firing pattern, you will always have lifter on base circle of cam. also, will not get lost as to where you're at. the newer style lifters do not need or require 3/4 turn , you will have problems if you do.1/4 turn will equal .050 preload, which is plenty.all this is done with motor off.
 
Perfacar-- Yeah I think that sounds a lot better with the motor off. I'm thinking of doing it that way. I had a turbo honda and whenever I changed out cams I would do it that way. It seems almost impossible to adjust them while the thing is running. It's just kind of weird because I have like 5 or 6 mopar books and none of them really say anything about rocker arm adjustment. I'm just nervous because I have some really expensive heads with 5 angle valve job ferrea valves. I guess I'll listen to you perfacar. Hope it works


thanks for the help. I would be screwed without this site.....
 
I dont se them running either. Old chevys are supposed to, and sometimes you'll see the modified valve covers that guys used to swap on for setting them. The deal was, with chevy, you are tightening the nut on a stud in the center of the rocker. Not an allen head set screw and locknut on the end of the rocker. Something that needs to be considered too..If you have aluminum heads, do one side hot, button it up and re-fire, let it warm up again, then set the other. Trying to do both sides at once with aluminum leads to a few valves being loose later.
 
The preload on hydraulic lifters is supposed to be between .020 and .060". If you know the number of threads per inch on the adjuster screw you can calculate how many turns you need. Most of the adjustable rockers use a 24 thread per inch adjustment screw so: 1 divided by 24 = .041" per turn. I like to set the adjustment in the center of the range at .040" - or 1 turn after the slack is taken out of the pushrod. Makes it a little easier to understand.
 
so how are u going to hold the gage,wrench and screwdriver at the same time find a mopar guy ask him for help or a good shop.Now I know shivy guys call them slopars.I'm just assuming its a solid stick. :wack:
:wack: :wack:.Do your self a favor if you do not have one you can get a mopar performance engine book at any mopar dealer.lots of good info good luck sounds like you got some $ tied up in the engine.I've made mistakes my self.when in doubt ask for mopar help.
 
wow this is really interesting how many different ways of doing this there are. I think we know that the preload has to be between .020 .060 and that .o41 per turn calculation was impressive. How about this

http://www.forabodiesonly.com/mopar/showthread.php?t=533

I did this today on the 360. It's weird though because some of the adjusters are out farther than others. If it is slightly off it won't hurt anything when I start it up right?
 
I have measured the required movement of pushrod with a dial indicator. one full turn is way too much preload, one quarter turn will produce .050 preload on the lifter. I run a 340 with adjustable rockers and hyd. lifters in a race motor. preload becomes critical if not done precisely. too much preload, will cause pump up. If you don't mind a very little valve noise, set them at zero lash. it's a better method anyway.
 
I have used yet another method to set the preload. If your lifters have a snap ring you can set each lifter individually by measuring the space between the snap ring and the lifter plunger using a round spark plug type feeler gauge. Start by setting the lash to zero (no longer able to spin the pushrod freely and there will be no clearance under the snap ring). Then adjust the preload and measure to the desired clearance. I have used this method. It is quite time consuming.
 
I also believe one full turn is too much pre-load for performance application. Ok for lower rpm mostly stock engine. Zero lash and 1/2 turn always worked for me. Good luck, Terry.
 
I agree. 1/2 turn at the most. I just put a set of Proform rorkers on my
340. Made sure the lifters were all the way down in the bore. Rotated the
push rods till they were unable to turn. Gave the rocker adjustment another
1/2 turn. and tightened down the jamb nut. Fired it up and it ran great.
Good luck, Green Duster.
 
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