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I just installed these lifters and I’m questioning my measurements. I measured 4 different cylinders with my pushrod tool and got between 7.4125 and 7.405. These lifters call for .035 +/- .010 preload. So I went to put in 7.450 pushrods. However when I install rockers to zero lash (mark them with silver line at zero lash) and then torque them to 22ft lbs I only get about 5/8 turn on the bolt. Does this sound right?
I never quite understood the turning of the bolt and it's effect on pre-load.
I always measure for 0 lash with my rockers torqued down, then add pre-load.
I also measure for all 16 pushrods and write it down for each one, I've always had to order at least 2 different lengths of pushrods to keep them all within Johnson's recommended pre-load range. After doing that I measure each pushrod with a caliper and match them up to each valve as close as possible.
OP... You need to measure each valve. Use a set of 8-12" calipers and measure the overall length of the pushrod tool each time you check for zero lash. Use some teflon tape on the threads of the tool to keep it stiff so it doesn't turn too easily on you. Once you get zero lash on all, and you have all 16 measurements, you will need to group a few rods together in different lengths to get a full set. So say you get 7.400 for your zero lash on 7 rods, 7.410 on 4 and 7.385 on the last 5. (Most likely you will find the exhaust are all about the same and the intakes are close to the same). You will need to call manton, trend, etc, give them your lengths and how you measured plus the 35 thou. If it is an aluminum block, go with the high side of the tolerance for expansion when warm. Shoot for around 40-42 thou of preload.
You torque the rocker down.
Spin the pushrod to get zero lash.
Then measure the pushrod with calipers.
Add the preload to that number.
Do that 16 times.
Tedious but necessary.
However when I install rockers to zero lash (mark them with silver line at zero lash) and then torque them to 22ft lbs I only get about 5/8 turn on the bolt. Does this sound right?
The torque procedure is not part of a preload measurement.
When you receive your pushrods you can verify proper lifter preload using an "angle of turns" method. Set the pushrod in place and adjust lifter to zero lash. Then gently turn the rocker bolt while counting turns until the stack up of parts come together and you just begin to feel resistance to turning of the bolt. That is point where preload is set.
Any turns of bolt beyond that does not change preload, does not change the height of stack of parts. The extra turns are only stretching the threads to achieve bolt tightening torque. Those extra turns to reach torque have nothing to do with preload
These lifters call for .035 +/- .010 preload. So I went to put in 7.450 pushrods.
These are not normal lifters, you need to go into greater detail than that to ensure you won't have problems.
The short travel lifters don't actually need that much accuracy. Main goal is to not overload the lifter. A 0.025" preload when hot is perfect (corresponds to 0.040 cold). A window of 0.038 - 0.045" preload during assembly is a good range. Johnson is being really conservative about the preload tolerance because they don't want to overload the lifters, they used to advertise wider specs with the same product. The point of all the attention to detail is to aim small so you miss small.
Pushrod checkers suck for accuracy. Use the checker tool to establish zero lash, then remove and measure the tool length with a 12" caliper. Do this for every rocker. These are not normal lifters, you need to pay attention to the details. Then call Manton and they will make further adjustments for final length of pushrod (corrections for lifter preload, engine growth at operating temperature, and geometry differences of ball end of checker tool vs. actual pushrod.) They will take those final numbers and sort into groups to decide how many different lengths of pushrods to give you and which rockers will be in which group.
Manton pushrods have a 0.003- 0.008" tolerance as manufactured at 70°F temperature and will grow or shrink by 0.015" with a 25°F temp swing. Don't freak out when the pushrods end up being a little different than nominal numbers on paper, just verify all the lengths in each grouping are reasonably correct and similar before installing in your engine. Verify preload during assembly with an "angle of turns to seat" method I described earlier.
Have Manton etch the length on each pushrod. It’s an option now, and runs like $35 I think. Well worth the money.
Good advice!! To the OP:
I would also forget counting bolt turns, and guessing what torquing does (actually nothing-All torquing does is tension/stretch the bolt). All counting the bolt turns does is make more work, and possibly skew the results. When you're working with +-.010", counting bolt turns doesnt cut it. A PR checker is the only way to do this right. Che70velle made a very good suggestion on etching the PR length. I would also add that it would be a good idea to draw up a schematic/map/whatever you want to call it, listing the 16 pushrod locations and list the length for each PR at that location, and denote whether the location is intake or exhaust. Then guard it with your life!!! Like, put it in one of your old girlie foldout mags, the ones in the garage that the wife doesn't know about!!!!!
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Johnson 2116LSR lifter preload question 
