big hammer

You guys are making a mountain out of a molehill here

handyandy496

iTrader: (9)

Isint that the idea behind the go faster or go home thing. You have a mountain! lol.

vettenuts

iTrader: (4)

Probably stripped threads. The torque is set to stretch the bolt a predetermined value by GM. A quarter turn beyond that will likely do damage. Don't exceed 22 lb-ft.

JimmyGTO

So with all the discussion in this thread it really comes down to just torque the rocker arm bolt to 22ft lbs. True/False? What would be the preload at 22ft lbs?

svede1212

iTrader: (3)

That depends on push rod length. Torquing the bolt fastens the bolt. The push rod sets the preload.

JimmyGTO

Thanks Svede. I finally caught on. Did some digging this morning. This is my first time breaking down a LS motor. I'm old school. I'm used to the old GTO's. Own 16 of them. But I'm learning a lot from forums like this.

Darth_V8r

iTrader: (4)

the preload at 5 ft pounds is the same as 22 is the same as 45 ( don't do 45). Torque is bolt stretch, not preload. Do not count torque towards preload.

5_litre_eater

Alright, This might be a dumb question, but how do you measure preload with a dial indicator? For some reason I can't wrap my mind around it.

tadams72

In the most simplistic terms. Using an adjustable pushrod, I like the one with the lock nuts, adjust it to zero lash with the rocker arm torqued or at least tightened to remove all slop between it and the pedestal. Lifter should be on the base circle of the camshaft. Remove adjustable pushrod and measure over all length (end to end) with the dial caliper. Add desired preload to that measurement repeat for all lifters and order pushrods.

big hammer

Go 1/4-1/3 turn past zero lash then go slay some putchka. Anything beyond that and you're left wondering why zero plus zero equals zero

vettenuts

iTrader: (4)

I set mine in line with the pushrod on the rocker arm with the tip in the oil hole so there was a preset in the dial indicator. Zero it out on the dial and then tighten down the rocker. Then you have to wait for the lifter to bleed out to get the final preload as the rocker will open a bit during tightening. This is the most accurate way to figure out the preload but a bit of a pain to do. I use this as a final check of my pushrod length.


Here is a lengthy thread that may help explain some of this: Lifter Preload Thread

transwiz

iTrader: (26)

I tried to use a dial indicator the other day.The problem is I couldn't get the torq wrench in there to tighten the rocker arm. I put the indicator at the pushrod end of the rocker arm. set it to the same angle of the pushrod.The dial was too big to get the torque wrench in there. Are you guys using a small dial gauge or what? I got frustrated and ordered a comp pushrod length checker. Does somebody have any picks of this procedure.

dave04da

iTrader: (2)

You don't need to use a torque wrench to tighten the rocker bolt down. I used a 1/4 drive ratchet. You don't have to get it too 22 ft lbs just till you feel enough resistance where you have to apply quite a bit of force to continue to turn the bolt ( This was stated by Darth_V8r on a previous thread) I also did this with the adjustable pushrod. I set the length I wanted with calipers an then used electrical tape to keep it from moving. I used the known lengths that are available and added .015 to that. I ended up using 7.325 pushrods which actually measured 7.341 end to end when I got them from BTR.