Re: Rocker Arm torque specs?
[Re: mopowergtx]
#84956
07/06/08 09:34 PM
07/06/08 09:34 PM
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Anonymous
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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.
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Re: Rocker Arm torque specs?
[Re: moparman383]
#84959
07/06/08 11:44 PM
07/06/08 11:44 PM
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Anonymous
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thoughts? yup.. seen lots of pulled out threads when going to factory torque specs. i swear chrysler made a typo in the FSM's.
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Re: Rocker Arm torque specs?
[Re: mopars4ever]
#84961
07/07/08 11:46 AM
07/07/08 11:46 AM
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Joined: Jun 2006
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mopowergtx
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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.
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Re: Rocker Arm torque specs?
[Re: mopowergtx]
#84962
07/07/08 09:45 PM
07/07/08 09:45 PM
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Anonymous
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never did i say "broke the bolts". just the threads letting go ona big dude.
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Re: Rocker Arm torque specs?
#84963
07/08/08 09:46 AM
07/08/08 09:46 AM
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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
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Re: Rocker Arm torque specs?
[Re: moparman383]
#84965
07/08/08 12:34 PM
07/08/08 12:34 PM
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Joined: Jan 2003
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ZIPPY
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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!
Rich H.
Esse Quam Videri
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Re: Rocker Arm torque specs?
[Re: moparman383]
#84967
07/08/08 12:47 PM
07/08/08 12:47 PM
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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.
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Re: Rocker Arm torque specs?
[Re: ZIPPY]
#84968
07/08/08 06:09 PM
07/08/08 06:09 PM
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mopowergtx
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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.
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Re: Rocker Arm torque specs?
[Re: mopowergtx]
#84969
07/08/08 06:36 PM
07/08/08 06:36 PM
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Anonymous
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some of you guys are putting WAY to much faith in those threads. but thats just my opinion.
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Re: Rocker Arm torque specs?
#84970
07/08/08 07:16 PM
07/08/08 07:16 PM
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Pacnorthcuda
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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.
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Re: Rocker Arm torque specs?
[Re: ZIPPY]
#84971
07/08/08 07:38 PM
07/08/08 07:38 PM
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Joined: Dec 2004
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moparman383
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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!
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Re: Rocker Arm torque specs?
[Re: ZIPPY]
#84973
07/09/08 01:23 PM
07/09/08 01:23 PM
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that a great idea. but my rocker arm holes are smaller than the pushrod diameter
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Re: Rocker Arm torque specs?
[Re: ZIPPY]
#84974
07/09/08 04:20 PM
07/09/08 04:20 PM
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moparman383
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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!
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Re: Rocker Arm torque specs?
#84975
07/09/08 04:37 PM
07/09/08 04:37 PM
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Joined: Jan 2003
Posts: 17,801 S.E. Michigan
ZIPPY
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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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