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Rocker Arm torque specs?

Posted By: moparman383

Rocker Arm torque specs? - 07/06/08 11:46 PM

I am putting my 383 back together and can't find the torque specs to put my rocker arms back on. The motor is not stock, the heads are edelbrocks and the rocker arm/rockers is from crane.

Any info is appreciated. Thanks!
Posted By: mopowergtx

Re: Rocker Arm torque specs? - 07/07/08 12:04 AM

FSM in front of me here says 25 ft. pounds for BB rocker shaft bolts.
Posted By: moparman383

Re: Rocker Arm torque specs? - 07/07/08 12:08 AM

Thanks!

Did it happen to say to tighten in stages up to 25lbs?

To make sure we are on the same page, I am asking about the 2 bolts on the ends and the 2 nuts in the middle of the shaft.
Posted By: mopowergtx

Re: Rocker Arm torque specs? - 07/07/08 12:16 AM

HUH? Dont you have stock type rocker shafts with 5 pedastal mounts?
Posted By: moparman383

Re: Rocker Arm torque specs? - 07/07/08 01:31 AM

Yeah, I typoed. It has 3 bolts and 2 nuts in the middle. Sorry.
Posted By: Anonymous

Re: Rocker Arm torque specs? - 07/07/08 01:34 AM

Quote:

FSM in front of me here says 25 ft. pounds for BB rocker shaft bolts.




i would minus 10ft-lbs off of that. ask me how i know.
Posted By: moparman383

Re: Rocker Arm torque specs? - 07/07/08 03:02 AM

The lifters are already full of oil and under pressure, so when I tighten them down I am afraid of all that pressure tightening them down might strip the threads in the aluminum heads.

Any thoughts on this?

FYI: all I did was take the heads off to change the gaskets, didn't drain the oil, nothing was done to the engine, etc. Just replaced gaskets and sealed what I could off and gave it a quick paint job.
Posted By: buildanother

Re: Rocker Arm torque specs? - 07/07/08 03:43 AM

Edelbrocks? Just turn them down a little at a time and switch from time to time and keep the shaft level while tightening. Also keep an eye on pushrods that may want to fall out of the rocker arm seat.
Posted By: Anonymous

Re: Rocker Arm torque specs? - 07/07/08 03:44 AM

thoughts? yup.. seen lots of pulled out threads when going to factory torque specs.
i swear chrysler made a typo in the FSM's.
Posted By: mopars4ever

Re: Rocker Arm torque specs? - 07/07/08 02:02 PM

25ft pounds is too much IMO. Mike
Posted By: mopowergtx

Re: Rocker Arm torque specs? - 07/07/08 03:46 PM

Quote:

25ft pounds is too much IMO. Mike




Remember this is a Big Block with the 3/8" bolts not the small block with the 5/16" bolts. 25 ft lbs on a 3/8" bolt isnt extreme. Small block grade 5 5/16" bolts would probably be stretching at 25 lbs.

And for typo's in FSM, for fun if you got one, look up the torque specs for a small block rocker shaft bolt in the 1969 Plymouth manual. It says 40 ft lbs! I'd like to see you get a 5/16" grade 5 bolt evan close to that before it breaks in half. 20 lbs on them scares me that they are stretching.
Posted By: Anonymous

Re: Rocker Arm torque specs? - 07/08/08 01:45 AM

never did i say "broke the bolts". just the threads letting go ona big dude.
Posted By: Anonymous

Re: Rocker Arm torque specs? - 07/08/08 01:46 PM

Ive scared myself tightening these bolts to 25 as well. I don't do that anymore.... I go to 15. It just seems like either the threads are pulling out or the shaft is crushing- you know that feeling you get right before you strip out a bolt? thats the feel of going to 25 ftlbs
Posted By: moparman383

Re: Rocker Arm torque specs? - 07/08/08 04:27 PM

My problem is that the lifters have oil in them and some are under pressure, so trying to tighten the shaft in equal increments is almost impossible because some are tight with 1 turn and others are way loose.

We were wondering if we should push the oil out of the lifters first so we don't overtighten and strip the bolts. Any thoughts on this?
Posted By: ZIPPY

Re: Rocker Arm torque specs? - 07/08/08 04:34 PM

On hydraulic lifters that are already pumped up and stock type stamped rockers I've had good luck either using a 3/8 speed handle, or choking way up on a ratchet, and very gradually/very slowly working the bolts down a little at a time. Eventually the shaft will bottom out on the pedastals and when it does, THEN I torque to spec in 2 or 3 increments to make sure I'm not being fooled. If the job is rushed and the bolts individually reefed on, something will get screwed up for sure.

Solids are easier!
Posted By: moparman383

Re: Rocker Arm torque specs? - 07/08/08 04:43 PM

Mine are hydraulic. That's what I was afraid of - false readings because the shaft has not bottomed out. Thanks for the help!
Posted By: Anonymous

Re: Rocker Arm torque specs? - 07/08/08 04:47 PM

i would be more concerned about the spring pressure that the hydraulic lifter being pumped up- unless of course your lift is so high that you bottom out a valve.
Posted By: mopowergtx

Re: Rocker Arm torque specs? - 07/08/08 10:09 PM

Quote:

or choking way up on a ratchet




Thats how I've always done them myself. Watch to see when the shaft is tight on the pedastals and give a little bit more choked up on a 3/8" ratchet and never had a problem. I had my shafts on and off several times on my recent SB build and the first time I torqued them to 18 ft lbs and didnt like it. Went back to my old "feel" way. But I wouldnt be afraid on an iron head BB with the 3/8" bolts going to 25 ft lbs with a torque wrench. But anything over a little squeeze past flush on the tightening seems unecessary anyway.
Posted By: Anonymous

Re: Rocker Arm torque specs? - 07/08/08 10:36 PM

some of you guys are putting WAY to much faith in those threads.
but thats just my opinion.
Posted By: Pacnorthcuda

Re: Rocker Arm torque specs? - 07/08/08 11:16 PM

Quote:

some of you guys are putting WAY to much faith in those threads.
but thats just my opinion.




Crushing the shaft is a bigger concern, but I've been using 25ftlbs on BB for a long time and never had a problem.
Posted By: moparman383

Re: Rocker Arm torque specs? - 07/08/08 11:38 PM

Quote:

On hydraulic lifters that are already pumped up and stock type stamped rockers I've had good luck either using a 3/8 speed handle, or choking way up on a ratchet, and very gradually/very slowly working the bolts down a little at a time. Eventually the shaft will bottom out on the pedastals and when it does, THEN I torque to spec in 2 or 3 increments to make sure I'm not being fooled. If the job is rushed and the bolts individually reefed on, something will get screwed up for sure.

Solids are easier!




Okay - my heads are Edelbrock aluminum and have the ADJUSTABLE rocker arms with hydraulic lifters.

Should I bleed the lifters off because when I'm tightening that is putting pressure on the valves and I'm afriad I'll strip the threads.
Or should I back the adjustments all the way off, bolt the pedastals on and readjust the valves?
I am trying to prevent adjusting the valves because I don't know anything about doing that and don't care to learn at this point - it ran great when apart and don't want to screw with it.

Thanks!
Posted By: ZIPPY

Re: Rocker Arm torque specs? - 07/09/08 04:24 PM


I do it this way.... pull all the adjusters completely out of the rockers.....torque the shaft assemblies to spec on the head...drop the pushrods THROUGH the still-open adjuster holes into the lifter cups....replace as many adjusters as possible, rotate the engine to get the ones that were at max lift in, then re-adjust either lash or preload.

I don't know of a way to do it without re-adjusting.
Posted By: Anonymous

Re: Rocker Arm torque specs? - 07/09/08 05:23 PM

that a great idea. but my rocker arm holes are smaller than the pushrod diameter
Posted By: moparman383

Re: Rocker Arm torque specs? - 07/09/08 08:20 PM

Quote:


I do it this way.... pull all the adjusters completely out of the rockers.....torque the shaft assemblies to spec on the head...drop the pushrods THROUGH the still-open adjuster holes into the lifter cups....replace as many adjusters as possible, rotate the engine to get the ones that were at max lift in, then re-adjust either lash or preload.

I don't know of a way to do it without re-adjusting.




That is a great idea - we called a Ford friend who gave us some advice on adjusting adjustable rockers on alum. heads so we had planned on re-adjusting at this point...

I'm afraid I might be in the same situatio as cucu, with too large of a pushrod to fit through the holes. We were able to get the shaft tight last night with the rockers attached, now just need to rotate the motor to get them all adjusted properly.

At the time of my post we were thinking of trying to push the oil out of the hyd. lifters but our friend said that was a near-impossibly task without taking more apart.

Thanks everyone!
Posted By: ZIPPY

Re: Rocker Arm torque specs? - 07/09/08 08:37 PM

Quote:

that a great idea. but my rocker arm holes are smaller than the pushrod diameter




Great point, also it's not going to work with conventional ball/cup pushrods, the cup will get stuck in the adjuster holes regardless of pushrod size.

Works like a charm with 5/16" one piece ball/ball pushrods and Comp 1321 rockers though, and that's my current setup, so that's why I was thinking about it.

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