Do I need to lash/preload rockers after removal?

[TB1LD]

Trying to prevent myself from doing something stupid (again) if I can. I’ve got a fresh build 440 with engine dyno/break in being the only run time. I had to pull both heads to have two broken exhaust studs machined out. Anywho; I’m putting the rockers back on and am unsure if they need re-lashed/preloaded. Everything (rockers and pushrods) came out and are back in in the exact order as they were removed. I did not loosen the individual rockers upon removal, just the 5 nuts holding the rocker shaft. Can I just align the pushrods and torque the shaft nuts being nothing was adjusted or does it need done from ground zero? Roller rockers and lifters. Thanks forum fam!

 

[PurpleBeeper]

Re-set the lash

 

[RemCharger]

Yeah. Take a look at the difference in the adjuster height. Who knows what's going on.

 

[TB1LD]

Pushrods and rocker shaft are just sitting there temp installed. Nothing aligned or tightened down yet

 

[pnora]

Its a no brainer. Covers are off and it takes a whole 30 minutes if that to run the lash.

 

[TB1LD]

Its a no brainer. Covers are off and it takes a whole 30 minutes if that to run the lash.

Fair enough. Something I’ve never done and after dropping the coin I did on the build the question needed to be asked. Thanks for the input

 

[RemCharger]

Fair enough. Something I’ve never done and after dropping the coin I did on the build the question needed to be asked. Thanks for the input

And don't do the old mopar chart. Intake opening, exhaust closing. And you need to know what the lifter manufacturer wants for preload. If it's indeed a hyd lifter. Or conversely a solid. ( unanswered questions)
You only get so much adjuster range with those ball ball rockers.

 

[gkent]

Hydraulic lifters wouldn't matter. Solids - I would at least check them.

 

[TB1LD]

And don't do the old mopar chart. Intake opening, exhaust closing. And you need to know what the lifter manufacturer wants for preload. If it's indeed a hyd lifter. Or conversely a solid. ( unanswered questions)
You only get so much adjuster range with those ball ball rockers.

You’ve stated exactly what’s going through my mind. I’m thinking my best bet may be to touch bases with my engine builder. There’s some variables here that aren’t giving me the warm fuzzy on doing this for the first time

 

[TB1LD]

Hydraulic lifters wouldn't matter. Solids - I would at least check them.

Reading up on that exact concept led me to this post. I’m unfortunately a bit ignorant to valvetrain variables if you will. Can I tell by visual/physical insp if mine are hyd or mech or is this a question for my eng builder? Build sheet ppwk is giving me that info. Thanks

 

[TB1LD]

Reading up on that exact concept led me to this post. I’m unfortunately a bit ignorant to valvetrain variables if you will. Can I tell by visual/physical insp if mine are hyd or mech or is this a question for my eng builder? Build sheet ppwk is giving me that info. Thanks

*isn’t giving me that info that is..

 

[RemCharger]

We just don't know how mechanically adept you are to learning the intracies of preload and soild lash setting / adjusting. You may need different pushrods.

 

[RemCharger]

Hydraulic lifters wouldn't matter. Solids - I would at least check them.

Some of them are extremely specific where they want them set. Hydraulics that is.

 

[gkent]

Some of them are extremely specific where they want them set. Hydraulics that is.

Really !! I want to meet the guy who can measure preload within a thou !!!

 

[TB1LD]

We just don't know how mechanically adept you are to learning the intracies of preload and soild lash setting / adjusting. You may need different pushrods.

Why would different pushrods be needed in this situation? Are you saying if rockers were adjusted out of spec and resulted in bent rods?

 

[493 Mike]

Perhaps you need professional help to feel comfortable?
Mike

 

[gkent]

Y'know, the whole top end is apart. For the sake of another 1/2 hour I'd re-adjust the preload. If only for peace of mind. Do it now while the valley cover is off. Check your pushrods to make sure none are bent - roll them on a nice flat surface. Make sure each pair of rockers has side clearance when the shafts are bolted down. A minimum of .010" per pair. Don't overtighten the shaft bolts - 25 ft lbs.. Adjust the rockers using the Mopar chart - back the adjusters off all the way then spin the pushrod with your fingers as you tighten the adjuster - when the pushrod won't spin you're at ZERO - now tighten the adjuster to the recommended number of turns and tighten the nut. Move on to the next pair.

 

[Green72]

YouTube is your friend!!!!between the guys on here and YouTube I built a 512 inch stroker as my first engine build

 

[threewood]

And don't do the old mopar chart. Intake opening, exhaust closing.

Could you elaborate on why using the lash chart would be problematic?

 

[pnora]

Could you elaborate on why using the lash chart would be problematic?

Cam profiles. With that being said there is a possibility that using the Mopar chart the cam may not be setting on the baseline when adjusting the valves. The other method eliminates that possibility.