silverado777 Posted July 8, 2008 Report Share Posted July 8, 2008 How do you adjust roller rockers? I think it's like a 1/4 turn past zero lash. But what is zero lash? Is it when the rocker doesn't move side to side? Or when you can't put a feeler gauge under the roller? Or when you cant turn the push rod? (the push rods are a pain in the butt to turn by hand) Any help would be appreciated! Quote Link to comment Share on other sites More sharing options...
12'SROCK Posted July 8, 2008 Report Share Posted July 8, 2008 (edited) what motor is it for? are they self aligning rockers or require guide plates? are the heads studed for the rockers? Edited July 8, 2008 by 12'SROCK (see edit history) Quote Link to comment Share on other sites More sharing options...
misterp Posted July 8, 2008 Report Share Posted July 8, 2008 (edited) "Zero Lash" means the point where all the slack has been removed in the valvetrain - it is the instant when the lifter, pushrod, rocker arm, and valvestem intimately contact each other. The problem with the "spin the pushrod" method is that because everything is oily/lubricated, you will achieve zero-lash and still be able to spin the pushrod (!); same with moving the rocker, it's side-to-side clearance has *nothing* to do with preload adjustment, by the time you've wrenched down on the adjustment nut to stop the rocker arm from moving you'll have overtightened it by a mile; and the feeler guage method will not work because the preload plunger inside the lifter is designed to move and that screws up any attempted measurements between the valvestem and roller tip. So my answer, NONE of these methods works on a hydraulic lifter unless you're the kind of mechanic that thinks "close" is good enough for horseshoes, handgrenades, and your valvetrain (not!). I should make a video for this; I just put new springs in the car a little while back. What you are trying to do is this - a hydraulic lifter contains a little spring-loaded "plunger cup" that the pushrod seats/sits in, and you want to tighten down the rocker arm nut enough that this plunger is compressed 1/2-way down it's bore inside the lifter. So you need to know the lifter plunger travel (typically 0.125") and then with the lifter on the HEEL of the cam lobe you tighten the rocker arm adjusting nut until the pushrod has been compressed 1/2-way down the bore of the lifter (or about 0.060" in this case). The REDNECK way to do this is to remove the valley cover so you can SEE the lifter plunger, and use your fingertips to screw down the rocker arm set screw until you SEE the instant where plunger begin to move - this is zero lash; you'll be close give or take about 10-thousandths of an inch which for our valvetrains is not perfect but ok-enough. The RIGHT way to do this is to mount a dial indicator so that tip of the instrument is riding on the lifter plunger cup -OR- on top of the pushrod-side of the rocker arm (preferably parallel to the pushrod); as you begin screwing down the adjusting nut with your fingertips you will discover the point where the dial indicator moves showing that the pushrod/lifter preload cup has begun to move (this is the zero lash point). Once you've found zero-lash, continue tightening down on the adjusting nut until the pushrod has compressed the preload plunger halfway (typically 0.060") and that's your valve adjustment; lock down your polylock setscrew and it's set for life. Another cheat is to do the math - if your adjustment screw has 24 threads per inch (typical imperial fine thread) then 1" / 24 = 0.042" per turn, or in other words approximately 1-1/2 turns is just a tick more than 0.060" preload. Again assuming 24-TPI, you'll have to refigure for different thread pitches; if for example your adjustment screw is 18-TPi then 1" / 18 = 0.55" so you would only screw down 1-turn with that hardware... BUT even using the mathematic method, you still need to determine zero lash and IMO the only way to do this right is to have a dial indicator. ALSO - while you're at it - when your lifter is correctly preloaded the top of the rocker arm should be CENTERED on the valvestem, if it's not then you need different length pushrods or the first time you send the valvetrain into valve float will likely be your last. And, if you add a degree wheel then you can also degree your cam as well to make sure it's installed/phased correctly. Mr. P. Edited July 8, 2008 by Mr. P. (see edit history) Quote Link to comment Share on other sites More sharing options...
12'SROCK Posted July 8, 2008 Report Share Posted July 8, 2008 heres how i have been doing it for several years on all old school SBC/BBC with hydraulic lifters only, 1/2-3/4 turn after zero lash, zero lash when you have no play in the push rod with up and down motion, be sure not to push the socket down on the rocker to avoid confusion with valve lash Small Block Chevy Valve Adjustment Order 0 deg TDC, both number one valves shut. Adjust the #1 exhaust valve Adjust the #1 intake valve Adjust the #3 exhaust valve Adjust the #5 intake valve Adjust the #7 intake valve Adjust the #2 intake valve Adjust the #4 exhaust valve Adjust the #8 exhaust valve Now rotate the engine 360 degrees. The mark on the balancer should be back at the TDC mark. Keep in mind that this is not the TDC where #1 would be firing! It's where #6 would fire. Adjust the #3 intake valve Adjust the #5 exhaust valve Adjust the #7 exhaust valve Adjust the #2 exhaust valve Adjust the #4 intake valve Adjust the #6 exhaust valve Adjust the #6 intake valve Adjust the #8 intake valve Quote Link to comment Share on other sites More sharing options...
misterp Posted July 8, 2008 Report Share Posted July 8, 2008 forgot the firing order trick, it saves a lot of time! Mr. P. Quote Link to comment Share on other sites More sharing options...
12'SROCK Posted July 8, 2008 Report Share Posted July 8, 2008 forgot the firing order trick, it saves a lot of time! Mr. P. yeah i learned the hard way LOL. . . .some people do each cylinder 90 deg at a time following the firing order 1-8-4-3-6-5-7-2 and there are many more methods out there but this by far the quickest and most accurate way Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted July 8, 2008 Report Share Posted July 8, 2008 would there be any benifit to using a solid lifter in our trucks? and what are self aligning rockers vs guide plates. Quote Link to comment Share on other sites More sharing options...
12'SROCK Posted July 8, 2008 Report Share Posted July 8, 2008 would there be any benifit to using a solid lifter in our trucks? and what are self aligning rockers vs guide plates. no solid roller lifters are use on race engines that have really agressive lobes/lift and that have high rpms to avoid valve float/lifter failure, there require more attention to valvetrain geometry/clearances and need to be adjusted periodically.self aligning rockers have side wall guides on both sides of the roller tip on the rocker to keep the roller from moving and keeping it centered on the valve stem, roller rockers that require guide plates do not have any at the roller tip there for require guide plates to hold the push rod in place so the roller rockers stay centered to the valve stem and also require hardend pushrods since they make contact with the guid plates Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted July 9, 2008 Report Share Posted July 9, 2008 Thanks Much! Quote Link to comment Share on other sites More sharing options...
mwalls54 Posted July 9, 2008 Report Share Posted July 9, 2008 it depends on the style of rocker. if your talking about the stock rockers on the sss then there is no adjustment just tq them down. Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted July 9, 2008 Report Share Posted July 9, 2008 (edited) it depends on the style of rocker. if your talking about the stock rockers on the sss then there is no adjustment just tq them down. and thats the difference when a rocker says adjustable or nonadjustable? Why would you what the adjustable? Edited July 9, 2008 by shadowsniper3006 (see edit history) Quote Link to comment Share on other sites More sharing options...
12'SROCK Posted July 9, 2008 Report Share Posted July 9, 2008 (edited) and thats the difference when a rocker says adjustable or nonadjustable? Why would you what the adjustable? some cylinder heads require them because they move the valve angle of the valves so the rocker/pushrod geometry needs to be adjusted or if you have a soild roler cam as well Edited July 9, 2008 by 12'SROCK (see edit history) Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted July 10, 2008 Report Share Posted July 10, 2008 ahhh, thanks again! Quote Link to comment Share on other sites More sharing options...
silverado777 Posted July 10, 2008 Author Report Share Posted July 10, 2008 Well, I guess I'll answer my own question. I read the instructions that came with the roller rockers. It say "Rotate the pushrod with your fingers and begin to tighten the polylock. When you feel the resistance on the pushrod, you are at zero lash. Rotate the polylock one half turn more and then tighten the set screw." Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted July 10, 2008 Report Share Posted July 10, 2008 Well, I guess I'll answer my own question. I read the instructions that came with the roller rockers. It say "Rotate the pushrod with your fingers and begin to tighten the polylock. When you feel the resistance on the pushrod, you are at zero lash. Rotate the polylock one half turn more and then tighten the set screw." i thought they did answer your question, and very detailed.... Quote Link to comment Share on other sites More sharing options...
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