|
Re: Rocker Arm torque specs?
[Re: mopowergtx]
#84956
07/06/08 09:34 PM
07/06/08 09:34 PM
|
Anonymous
Unregistered
|
Anonymous
Unregistered
|
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.
|
|
|
Re: Rocker Arm torque specs?
[Re: moparman383]
#84959
07/06/08 11:44 PM
07/06/08 11:44 PM
|
Anonymous
Unregistered
|
Anonymous
Unregistered
|
thoughts? yup.. seen lots of pulled out threads when going to factory torque specs. i swear chrysler made a typo in the FSM's.
|
|
|
Re: Rocker Arm torque specs?
[Re: mopars4ever]
#84961
07/07/08 11:46 AM
07/07/08 11:46 AM
|
Joined: Jun 2006
Posts: 3,075 Eastern Ohio
mopowergtx
master
|
master
Joined: Jun 2006
Posts: 3,075
Eastern Ohio
|
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.
|
|
|
Re: Rocker Arm torque specs?
[Re: mopowergtx]
#84962
07/07/08 09:45 PM
07/07/08 09:45 PM
|
Anonymous
Unregistered
|
Anonymous
Unregistered
|
never did i say "broke the bolts". just the threads letting go ona big dude.
|
|
|
Re: Rocker Arm torque specs?
#84963
07/08/08 09:46 AM
07/08/08 09:46 AM
|
Anonymous
Unregistered
|
Anonymous
Unregistered
|
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
|
|
|
Re: Rocker Arm torque specs?
[Re: moparman383]
#84965
07/08/08 12:34 PM
07/08/08 12:34 PM
|
Joined: Jan 2003
Posts: 17,845 S.E. Michigan
ZIPPY
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 17,845
S.E. Michigan
|
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
|
|
|
Re: Rocker Arm torque specs?
[Re: moparman383]
#84967
07/08/08 12:47 PM
07/08/08 12:47 PM
|
Anonymous
Unregistered
|
Anonymous
Unregistered
|
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.
|
|
|
Re: Rocker Arm torque specs?
[Re: ZIPPY]
#84968
07/08/08 06:09 PM
07/08/08 06:09 PM
|
Joined: Jun 2006
Posts: 3,075 Eastern Ohio
mopowergtx
master
|
master
Joined: Jun 2006
Posts: 3,075
Eastern Ohio
|
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.
|
|
|
Re: Rocker Arm torque specs?
[Re: mopowergtx]
#84969
07/08/08 06:36 PM
07/08/08 06:36 PM
|
Anonymous
Unregistered
|
Anonymous
Unregistered
|
some of you guys are putting WAY to much faith in those threads. but thats just my opinion.
|
|
|
Re: Rocker Arm torque specs?
#84970
07/08/08 07:16 PM
07/08/08 07:16 PM
|
Joined: Nov 2007
Posts: 21,825 Kirkland, Washington
Pacnorthcuda
Too Many Posts
|
Too Many Posts
Joined: Nov 2007
Posts: 21,825
Kirkland, Washington
|
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.
|
|
|
|
|
|