I installed 799 castings that were decked .030. I also installed Johnson 2110R lifters. The rockers are stockers with the CHE trunion upgrade. They're getting installed in an LS1.

I was able to get the intake valve on the base circle. I used a trick flow measuring tool (which is 6.8 at its lowest).

At 12.5 turns i could rock the rocker ever so slightly for a very very tiny click. At 12.75 turns it was stiff and I was unable to rock it at all. I double checked both of those measurements.

So am I correct in saying the math goes as such:
(12.75x.05)+6.8=7.4375

Then I take that number and add the desired preload, correct? Which for the Johnson 2110R should be approx .050 because after heating up it that would bring it to a desired .035 preload. So the Pushrods should be 7.4875.

Am I doing this right? Never done anything like this before. I know the lifters aren't full of oil so they could depress some too ..

 

Pushrod length and Johnson 2110-K preload - LS1TECH - Camaro and Firebird Forum Discussion You might find some helpful info in there.

 

Thank you. So it sure seems I did everything right except I could have possibly depressed the plunger during my measurement.

 

You're getting 12.75 turns of preload? Or am I reading this wrong?

1/2 of a turn is roughly .050 of preload

 

He's was referring to the PRL checking tool.

 

This is correct. I'm pretty positive I got this figured out.

 

Intake zero lash was 7.4375
exhaust was 7.35

I ordered eight 7.475 pushrods for the intake which gives .0375 preload which is a tiny hair less than I would have liked.
I ordered eight 7.40 pushrods for the exhaust which gives .050 preload

It's the closest I was able to get without going custom or ordering heavily backordered parts.

 

How many intake lengths and how many exhaust lengths did you measure?

I used the Comp Cams pushrod length checker, and the measurements I got were true to measuring with a caliper. When you order them, a lot of times they are sold as "gauge" length, which is a little longer than measured with a caliper.

I ordered 7.400" and received 7.412", which actually ended up perfect for what i needed.

Edit: every engine is different, but I normally see intake and exhaust pushrods pretty close in length. My last one was +/- .005" from longest to shortest.

 

I was surprised at the difference as well and I honestly initially thought I would need shorter than stock pushrods. I measured 2 different valves. All measurements were taken with the heads fully installed and torqued. Same with the rockers, torqued.

 

Spoke with Johnson and they said go ahead and run it with those preloads without issue.
Will report back if I have any problems, but I hope I'm all set. Pushrods will be here today and car should be road worthy this weekend.

 

I measure like Onbusy. The end to end vs gauge length is a bit confusing because the pushrod folks often don’t mention how they spec them.
At any rate, that .012” longer is actually a good thing.

I just measured up an LS1 with 243’s cut .035”.
Ordered 7.375” pushrods. At install I noted approx 1.25 turns of the rocker bolt from 0 to full preload. Right in the ballpark.

The Johnson’s may have a different cup height than other lifters. Never used them, just a guess.
In Tyler’s case, perhaps the valve stem heights ended up different from intake to exh due to the valve job, or non stock valves.?

 

They def are different than a standard LS7 lifter. These specifically are short travel lifters. As far as I know the valves are stock. I paid for a stage 1 job which uses stock valves.

I have read several posts about the short travel Johnsons requiring different length pushrods. My only concern at this time is that I feel like I need to go back and measure every single one... painstaking process lol

 

I had my pushrods made by Manton. Talked with them and they were great to work with. They will make any length you need

 

Well i measured a few more and they're different as well but most are needing a 7.4 rod. My head is spinning with numbers. Fun!

 

Cylinder 1 intake 7.4 rod exhaust 7.4 rod
Cylinder 2 intake 7.475 rod exhaust 7.4 rod
cylinder 3 intake 7.4 rod exhaust 7.4 rod

I'm starting to wonder if I compressed the lifter in the intake side of cylinder 2 and it didnt spring back up all the way. Thoughts?

Planning on measuring all remaining cylinders tomorrow. I know some people are like...just throw them in! Well I'm a very thorough person so I want this done right 100%.

 

I will go out on a limb here and say first, remeasure cyl.#2 intake, and IF it comes out to 7.400 like the rest measured out at so far, the rest too will come out to 7.400. But measure to be sure....

 

How are you making sure you are on the base circle of the cam for the pushrod you are measuring?

 

I have re measured it more times than I can count but for ***** and giggles I will again.

 

heads and gaskets installed and torqued to spec.
Insert a rod in the exhaust valve. Rotate the engine until I feel that rod start to come up. Take the measuring tool and start measuring the intake valve. Vice versa for the exhaust valve.

 

Everything is measured and re-measured and measured again... in some cases up to 6-7 times.

Every pushrod will be either a 7.4 or 7.375

EXCEPT cylinder 2's Intake (previously mentioned above) and cylinder 6's exhaust will require the longer 7.475 for some odd reason...

All the preloads will be within spec, with the lowest being .0375 and highest .050

Woohoo... time to put it together.