TA S2 aluminum heads / TA roller rockers / hydraulic roller cam and Johnson 2112OPR hydraulic roller lifters. The Johnson 2112OPR hydraulic roller lifters call for .035 +/- .010 lash. So from zero lash do the adjuster screws get turned 1 full turn for .050 preload to account for aluminum heads growing by .012?
No. I have TA Stage 2 SE heads, Johnson rollers and roller cam and set mine about 1/2 turn from zero lash. Originally I had Morel lifters but exchanged them and used the Morel instructions and had the Johnson's about 7/8 of a full turn, and had problems when the car warmed up popping in the exhaust during break in driving, from failure of some valves to be fully seating. Happened to read one of Larry's posts on the correct setting for the Johnson lifters and readjusted them, and am glad I did.
What is the thread pitch of that screw? Is the adjustment multiplied by rocker ratio, or is it on the pushrod end of the rocker?
When I bought my Johnson Roller lifters from Jim, he sent me this e mail, "Larry, These lifters are different.. they are a short travel lifter, that can only be pre-loaded .035.. That's about half a turn on your rockers.. I built that motor with 3/4 turn preload, and I think you have tightened it since.. so I think you will be adjusting, and there is absolutely no reason not to. Tips 1 take it apart at TDC on number one cylinder.. gives you a good reference point should something go amiss. Also the starting point for the adjustments procedure.. verify number 1 by looking at the position of the rotor ( it could be 1 or 6) 2. As mentioned above, check that preload.. I preload those lifters exactly a half turn past zero lash.. so they are near the max recommended running preload cold.. as the motor warms up, the heads expand, and you lose about .010 to .012 preload, so your well within the recommended range. You won't have issues until up around .050-.075 preload, so your safe, no worries about hanging valves open. 3. Observe the size of the bead of sealer on the end seals, and put on that much again, but don't go crazy with it. 4. Take your time... and do the valve adjustments with the intake off, and forget the silly patterns. Adjust the cylinder that is at TDC (should be number one when you start) and then rotate the crank 90 degrees, while watching the intake valve close on the next cylinder, and visually look to insure the lifter is on the base circle. This way you will have no question about your adjustment. The rotate and do the next cylinder, and so on, thru the firing order. Remember you have the 4-7 swap in the firing order. If there is any question, verify that via the plug wires. Good luck"
The motor is out of the car and on a stand. Intake off. Standard firing order. No 4-7 swap. According to TAs site a full turn of the adjuster screw is .050 so half a turn would be .025 of preload: http://taperformance.com/PDF/Roller_Rockers_Installation.pdf Since the heads grow .012 that would bring the preload from .025 down to .013 of preload when warmed up..that's a good bit off the target of .035 Johnson wants them at.. Probably will just go ahead set the adjuster screws to half a turn and call it good. Just trying to understand the math on this one
But if you go too far you will be out of specs when cold......I'd rather have too little preload than too much
I have to agree too little is better than too much on those, you can always readjust. I used to go thru this all the time with my 350 since it would get noisy after warming up, I did more and less same result so I just stayed at 1/2 turn down and no more.
They are much quieter than the Morels. The Morels were very noisy when the engine was fully warmed up. I tried a little more preload, but it made no difference. I read that the Morels liked a heavier oil, but I did not try that. JW had switched over to the Johnsons years before. I asked him if he thought I should switch over, and he said, yes, so I bought a set from him, and swapped them in. https://www.v8buick.com/index.php?threads/johnson-roller-lifters.322436/#post-2691760
