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So I have one head installed and torqued (passenger side) on a fresh built LQ4. Using Johnson 2110R. Initially, with pushrod length checker turned out 7.400" sounds about right and I ordered BTR 11/32 7.400s. First, I set my dial indicator to read preload (How much pushrod side of rocker arm goes down after zero lash until torques to 22 ft.lb) Which to best of my equipment accuracy, I read 0.044" to as much as 0.077" and between. Then tried counting turns, got 7/8 turn (lowest) 1 3/4 turn (highest) and between to get to that 22 ft.lb for 8 rockers on passenger side.
these Johnson 2110R are "short travel" and they want 0.040" +/- 0.010" preload. My readings are all over the place. Why is that? Some are in specified preload range with 7.4" pushrods but some are not. (need shorter pushrod possibly). Something is not right. obviously all readings made with lifters on base circle. Readings didn't show any rising pattern or such
side to side to blame block deck being not level. CNC ported heads by TSP with LS9 gaskets.
I also found on 2 lifters (all new lifters) I can push the plunger in by hand. I did spray some oil on them installing them but never actually filled them. Is that possible those 2 just "not filled enough" with that spray of oil I gave them and have air it them?
Another confusion is, some said 1 turn is 0.050" of preload with stock 1.7 rockers, some other say 0.078" of preload. which one is correct?
Most likely the variation in push rod length is because of valve & seat work or just wear. Not alot you can do about alot of that. PRs aren't all that $$$ anyway; best thing to do is to order 2 sets, that cover the whole range you're finding yourself in, and use the different lengths where they fit best. You could order custom PRs of course but that's $$$$. If near all are in one part of the range and only a few are in the other, you could order just a few individual ones, for the outliers.
You could also conceivably have the valves or seats cut or ground some more but that's kinda overkill. Or, you might could try swapping valves around, and re-lap them if necessary, so you put slightly shorter valves in places where the seats are cut or worn a bit deeper.
Preload belongs entirely to the lifter. It doesn't care in the slightest about rocker anything; ratio, material, brand, pivot design, whatever. If Johnson says .040" ± .010" on their lifters, then that's what you need to arrive at.
I'm not a fan of the "count the turns" method but if that's all you've got, get as good at it as you possibly can. I MUCH prefer the adjustable PR method. 22 ft-lbs isn't all that critical in any of this. That's just the standard "tightness" of that size hardware. It's all metal-to-metal anyway; once you get it tight enough that all the metal is all fully compressed together, nothing moves or changes size anymore. Don't get too wound up about that. It's the least of your potential sources of variation.
"Push the plunger by hand" is irrelevant. Once they have oil pressure in them they'll do what they're supposed to do.
Question: When you lay a straight edge acrross the tops of the valves do they all touch or are the tops of intake valves higher than the exhaust valves or vice versa? My guess would be they are all the same height or at least they should be otherwise you will need different length PR's for intake and exhaust or need to correct with lash caps. Instead of the dial indicator and the lifter plunger travel/turns @ 22 ft/lbs just take the PR length checking tool and a caliper gauge to find out what the PR length is at zero lash and see if you then get a consistent number. Once you've determined you have the right length @ 0 then add desired lifter preload and that will be what you need once you've torqued the rocker arm down.
Question: When you lay a straight edge acrross the tops of the valves do they all touch or are the tops of intake valves higher than the exhaust valves or vice versa? My guess would be they are all the same height or at least they should be otherwise you will need different length PR's for intake and exhaust or need to correct with lash caps. Instead of the dial indicator and the lifter plunger travel/turns @ 22 ft/lbs just take the PR length checking tool and a caliper gauge to find out what the PR length is at zero lash and see if you then get a consistent number. Once you've determined you have the right length @ 0 then add desired lifter preload and that will be what you need once you've torqued the rocker arm down.
Very good point. No, I have not. didn't even think about that. will do. I don't have that big of caliper. Will buy one. So you saying, dial indicator on top of PR oil hole in the rocker arm is not good? Can you clarify how do you translate one turn of bolt to 0.001s...since what dial indicator reads is not even consistent with turns. Going with PR length checker itself, I have range of 7.343" - 7.360 by best of my ability to convert turns to fraction of turns (some range of 10 3/4 - 11 1/4 turns) both without adding preload yet. Wish 2110 regular lifters are available instead of these "short travel" deal. Yet opened another can of worm for me.
Using the EOIC method I've always installed the PR tool onto the lifter knowing it was too short and then tighten the rocker arm down hand tight and start turning the adjuster on the PR tool until I took out the slack in the rocker arm and that was zero lash. Not always an easy thing to do and oftentimes it was remove the rocker arm and turn the adjuster in small increments and reinstall until I've reached zero lash. I'd carefully remove it from the lifter and measure the OAL (Overall Length) with a caliper gauge which you can usually borrow a digital one from your local parts store but it won't be one of the high end ones and they're not really needed either. Anyway, I'd do this to a couple of other cylinders just as double check to see if my readings were consistent. +/- 0.005. Your lifter preload calls for .040 +/- 0.01 so I'd probably shoot for .030 lifter preload.
Most likely the variation in push rod length is because of valve & seat work or just wear. Not alot you can do about alot of that. PRs aren't all that $$$ anyway; best thing to do is to order 2 sets, that cover the whole range you're finding yourself in, and use the different lengths where they fit best. You could order custom PRs of course but that's $$$$. If near all are in one part of the range and only a few are in the other, you could order just a few individual ones, for the outliers.
You could also conceivably have the valves or seats cut or ground some more but that's kinda overkill. Or, you might could try swapping valves around, and re-lap them if necessary, so you put slightly shorter valves in places where the seats are cut or worn a bit deeper.
Preload belongs entirely to the lifter. It doesn't care in the slightest about rocker anything; ratio, material, brand, pivot design, whatever. If Johnson says .040" ± .010" on their lifters, then that's what you need to arrive at.
I'm not a fan of the "count the turns" method but if that's all you've got, get as good at it as you possibly can. I MUCH prefer the adjustable PR method. 22 ft-lbs isn't all that critical in any of this. That's just the standard "tightness" of that size hardware. It's all metal-to-metal anyway; once you get it tight enough that all the metal is all fully compressed together, nothing moves or changes size anymore. Don't get too wound up about that. It's the least of your potential sources of variation.
"Push the plunger by hand" is irrelevant. Once they have oil pressure in them they'll do what they're supposed to do.
I agree with the above.
Using a dial indicator is good. You can loosen the rocker bolt and with slight finger presser zero the gauge, tighten the bolt , note the preload and back off the bolt to double check the preload. If the lifter is "pumped up" just be patience as the spring will bleed the lifter down for the reading. If the push rod is too long, you can put a shim under the rocker arm support if it is not too much, the aluminum will flex. Also I have removed material from the supports if the Push Rods are too short.
Hope that helps
I agree with the above.
Using a dial indicator is good. You can loosen the rocker bolt and with slight finger presser zero the gauge, tighten the bolt , note the preload and back off the bolt to double check the preload. If the lifter is "pumped up" just be patience as the spring will bleed the lifter down for the reading. If the push rod is too long, you can put a shim under the rocker arm support if it is not too much, the aluminum will flex. Also I have removed material from the supports if the Push Rods are too short.
Hope that helps
Thanks. it definitely helped. Rockers are used stock GM, blasted (very fine grit) then upgraded trunnion. They might not exactly worn the same. Valve themselves are also not new, TSP reused them. As I'm pushing them about 44 to 78 thousands to seat the rocker after zero lash (more like 55 to 77ish) I'll go ahead order 7.375" PR to lower preload 0.025" then hopefully by swapping rockers around I can bring them all in range. Sounds better than having different length PR. Few things:
- Do you read dial indicator as you just tighten the rocker to "seat" or "torque" it to 22 as a preload number? some said let it seat only (15 ft.lb), but I saw it actually pushed PR down another 0.005" if I torque it.
- Removing material. Where is the best place to do so (let's say I want few tho more preload) Rocker tray (where rocker seats)? tip of the rocker (where touches the valve)? or shim/ file under the tray itself (will this raise/lower others in that area?)
Thanks. it definitely helped. Rockers are used stock GM, blasted (very fine grit) then upgraded trunnion. They might not exactly worn the same. Valve themselves are also not new, TSP reused them. As I'm pushing them about 44 to 78 thousands to seat the rocker after zero lash (more like 55 to 77ish) I'll go ahead order 7.375" PR to lower preload 0.025" then hopefully by swapping rockers around I can bring them all in range. Sounds better than having different length PR. Few things:
- Do you read dial indicator as you just tighten the rocker to "seat" or "torque" it to 22 as a preload number? some said let it seat only (15 ft.lb), but I saw it actually pushed PR down another 0.005" if I torque it. Zero the dial with no preload, the rocker can be very loose at this point. Use slight finger pressure on the dial rod to zero, then tighten the bolt until the gauge stops moving but do not go over 22 ft lbs.
- Removing material. Where is the best place to do so (let's say I want few tho more preload) Rocker tray (where rocker seats)? tip of the rocker (where touches the valve)? or shim/ file under the tray itself (will this raise/lower others in that area?)
Remove material on the bottom of the tray-support where it lays on the head pad. Same place to add shims. The difference in push rod change will not be one to one. So recheck after shimming. I think that the aluminum has enough flex to not change the next seat, but I would not go over .020" on the bottom. I have added .010" under the rocker in the curved seat area if the push rod was still too long.
After two different machine shop valve jobs, I wish I had my own equipment. The first opened up the valve guides to much. The second did not give me the same installed valve height as I asked for. So that was the reason for the shimming on the rocker supports. I did not want to reorder the push rods again.
You shown a dial gauge in you first post, do you have a dial gauge? They can be a pain to set up, I can't find a magnet to stick to the aluminum!
Hope that helps, and I do not get Flamed!
PS I use the old beam type torque wrenches, never liked the clickers. Just as the threads on a bolt would be letting go [you can feel that] the clicker would release and you would have a stripped bolt. With a beam type you can stop as you see the torque is not increasing and stop then and figure out what is going on.
I used a piece of steel plate and secured it down with a stud (M8x1.25) using rocker bolt hole of neighboring cylinder. Perfectly parallel to rocker working on it. Then keep moving setup forward. Last 2 I use the same plate bolted to side of the head, and it'll provide a solid base for measurment.
Sure I don't have a setup like that. Hope I don't get to actually remove material like that by just swapping rockers around and find a good one, but If I have to do that, then I guess I'll take my time and use a file or something.
But back to original question, would you take reading by torqueing to 22 or just let the rocker "sit"...It does make some 5 to 10 tho. difference.
I am not sure what you mean---- so here it goes. But first. Good trick on mounting of the dial...
Rocker loose to find zero. Then torque, [at this stage I do not think you need to go to the full 22 ft lbs.] Just has to be tight. But most important is to let it sit. If the lifter has oil in it you will see the spring compress, you have to wait until it bleeds down to record the full preload. Maybe some lifters will take longer. Note:This process will not work if you are using light mock-up springs as the light spring will not bleed down the lifters.
Then to double check, loosen the rocker bolt and watch the dial, it should return to zero. The small spring inside the lifter should push the push rod back up.
I hope that is clearer than mud.
Have a good night.
I wouldn't change the distance between the rocker and head when using stock rockers. It changes the swipe pattern.
I'd find out the problem and correct it.
worms
Yes, the problem. Good point. Back to a good valve grinder that cares.
The correct fix would be restoring the correct installed valves stem height.
But changing from stock, the following would also change the wipe pattern:
Lifter preload
Valve lift
So pick your best worm!
Apart from having a proper valve job, and I know I did not mention this before. Checking the wipe pattern after shimming the rockers would be in order.
If the installed valves stem height is high, raising the rocker would be a close fix to restore the geometry.
Hope that helps
PS, checking the wipe pattern: am I correct in thinking that the only way to get a good wipe pattern is with a fully pumped up lifter?
Either by running the motor or having a solid lifter set at the proper preload depth that you could rotate the motor on an stand?
Last edited by Metalchipper; 12-31-2022 at 03:20 PM.
Reason: more worms
worms
Yes, the problem. Good point. Back to a good valve grinder that cares.
The correct fix would be restoring the correct installed valves stem height.
But changing from stock, the following would also change the wipe pattern:
Lifter preload
Valve lift
So pick your best worm!
Apart from having a proper valve job, and I know I did not mention this before. Checking the wipe pattern after shimming the rockers would be in order.
If the installed valves stem height is high, raising the rocker would be a close fix to restore the geometry.
Hope that helps
PS, checking the wipe pattern: am I correct in thinking that the only way to get a good wipe pattern is with a fully pumped up lifter?
Either by running the motor or having a solid lifter set at the proper preload depth that you could rotate the motor on an stand?
Lift and preload doesn't change the wipe pattern on a stock ls engine with stock rockers. Lift might make it larger.
You could check it with non pumped up lifters by using checking springs and preventing the lifters from compressing by lifting up on the pushrod side of the rocker.
Lift and preload doesn't change the wipe pattern on a stock ls engine with stock rockers. Lift might make it larger.
You could check it with non pumped up lifters by using checking springs and preventing the lifters from compressing by lifting up on the pushrod side of the rocker.
On the preload...........
Thanks, looks like I need to invite a worm for lunch! Preload would not change the wipe pattern.
Thanks for answering my question about checking the wipe pattern.
I would use the adjustable pushrod, torque the rocker arm to 22ft lbs and adjust it out till zero lash and measure it with dial calipers, then repeat x15
If there's a difference due to the valve job, valve too deep in the head etc. If you measured the install height of each spring, I would think you would have seen variation there.
Most likely the variation in push rod length is because of valve & seat work or just wear. Not alot you can do about alot of that. PRs aren't all that $$$ anyway; best thing to do is to order 2 sets, that cover the whole range you're finding yourself in, and use the different lengths where they fit best. You could order custom PRs of course but that's $$$$. If near all are in one part of the range and only a few are in the other, you could order just a few individual ones, for the outliers.
You could also conceivably have the valves or seats cut or ground some more but that's kinda overkill. Or, you might could try swapping valves around, and re-lap them if necessary, so you put slightly shorter valves in places where the seats are cut or worn a bit deeper.
Preload belongs entirely to the lifter. It doesn't care in the slightest about rocker anything; ratio, material, brand, pivot design, whatever. If Johnson says .040" ± .010" on their lifters, then that's what you need to arrive at.
I'm not a fan of the "count the turns" method but if that's all you've got, get as good at it as you possibly can. I MUCH prefer the adjustable PR method. 22 ft-lbs isn't all that critical in any of this. That's just the standard "tightness" of that size hardware. It's all metal-to-metal anyway; once you get it tight enough that all the metal is all fully compressed together, nothing moves or changes size anymore. Don't get too wound up about that. It's the least of your potential sources of variation.
"Push the plunger by hand" is irrelevant. Once they have oil pressure in them they'll do what they're supposed to do.
Pushrod checkers ftw!!! ONLY way to do it, ESPECIALLY with short travel lifters.....
12-30-2022, 04:52 PM
inconsistent lifter preload...advice needed 
can of worms 
