![]() |
|
|
|
Registered
Join Date: Jan 2002
Posts: 143
|
Scary Torquing Experience
Putting the engine back together with new ARP studs. Followed the manufacturer's procedure to the letter using the supplied lube on the threads and supplied washers and nuts. Did the 2 equal step torque down of the heads and cam tower. The first pass at 20 ftlbs went fine. The second step to 38 ftlbs was the scary part. Remember I had to install the new ARP studs due to the broken Divilar stud. So when I started the last pass at 38 some torqued up like you would expect. Some started turning and feeling normal and then they slipped. That was the scary part because I thought something snapped or threads stripped. Continued to turn the nuts and they all tighten down. I guess it was just the nut slipping on the washer or the washer on the head. Anyone had this experience with the ARP studs?
|
||
![]() |
|
Project Addicted
Join Date: Jul 2012
Location: Eastern Shore. MD
Posts: 919
|
Did you put lube under the nut and on the washer??
You were probably experienceing some torsional wind up in the studs (they are long) and the a release of that wind up. I would re-torque them again to the 38 to capture and excess windup or embedment.
__________________
Jon 1966 912 1976 911 3.4 Backdate Project 1986 944 |
||
![]() |
|
Registered
Join Date: Dec 2000
Location: philadelphia, pa
Posts: 594
|
What motor are you working on? For 65 through 89 911 the spec for head studs is 23.5 ft-lb torque.
|
||
![]() |
|
Registered
Join Date: Jan 2002
Posts: 143
|
This is a 1979 930. The supplied lube from ARP was used on the washers and nuts and threads. APR states 38 ftlbs for the studs.
|
||
![]() |
|
Straight shooter
|
Could also have been light galling. Make sure you spread the lube all the way down into the thread of the stud and nut thoroughly. If you have more to go then I would recommend running the lubed nut and stud together without the head to spread it on both parts well. Then re-lube lightly and install the head and torque.
__________________
“Of the value traps, the most widespread and pernicious is value rigidity. This is an inability to revalue what one sees because of commitment to previous values. In motorcycle maintenance, you MUST rediscover what you do as you go. Rigid values makes this impossible.” ― Robert M. Pirsig, Zen and the Art of Motorcycle Maintenance: An Inquiry Into Values |
||
![]() |
|
Registered
Join Date: Jan 2002
Posts: 143
|
I did re-torque today. Actually some nuts moved slightly. Hopefully all is OK.
|
||
![]() |
|
Banned
Join Date: Nov 2007
Location: Rockwall, Texas
Posts: 8,559
|
Quote:
ARP head stud torque procedure/settings |
||
![]() |
|
Registered
Join Date: Aug 2008
Location: Houston, TX
Posts: 161
|
Arp
I followed the procedure of 38ft/lbs on my 930 engine, I have been concerned with the high torque settings required by ARP, and does it put extra stress on the case boss threads
|
||
![]() |
|
Registered
Join Date: Jul 2008
Location: Spokane WA
Posts: 585
|
I had the same experience when torqueing my ARP studs: smooth increase in torque then a sense of release or slipping before reaching 38lbs. It does seem like an excessive amount of torque doesn't it? I performed the procedure exactly as ARP described them.
|
||
![]() |
|
Registered
Join Date: Jan 2002
Posts: 143
|
I assume you haven't had any problems since. How long ago did you install the ARP studs? Did you re-torque after the first 1000miles?
|
||
![]() |
|
Puny Bird
Join Date: Nov 2002
Location: Port Hope (near Toronto) On, Canada
Posts: 4,566
|
I just did a 930 with ARP studs, I didn't like that torque as well, I felt the same thing on a couple of studs, but they torqued down fine.
For my own engine I bought a set of Henry's studs. ![]()
__________________
'74 Porsche 914, 3.0/6 '72 Porsche 914, 1.7, wife's summer DD '67 Bug, 2600cc T4,'67 Bus, 2.0 T1 Not putting miles on your car is like not having sex with your girlfriend, so she'll be more desirable to her next boyfriend. |
||
![]() |
|
Registered
Join Date: Apr 2010
Location: Houston, Tx
Posts: 951
|
Did you guys loctite the studs into the case? If not loctited, that might explaing some of the release?
__________________
"Simplicity is supreme excellence" - James Watt |
||
![]() |
|
![]() |
Registered
Join Date: Jul 2008
Location: Spokane WA
Posts: 585
|
|||
![]() |
|
Registered
Join Date: Jul 2008
Location: Spokane WA
Posts: 585
|
Yes Loctite was used on the case threads. The Loctite had even cured for several days prior to torqueing. I called the ARP rep and he said it didn't matter if you used Loctite or the included ARP thread lube as long as the studs were not installed dry.
|
||
![]() |
|
Registered
Join Date: Jan 2002
Posts: 143
|
I used thread locker on the studs. Still going back together.
|
||
![]() |
|