#1  
Old 03-26-2023, 10:23 AM
dv657172 dv657172 is offline
Senior Chief
 
Join Date: Mar 2012
Location: Maryville, TN
Posts: 255
Default Torque specs - wet vs. dry

A general question:

Just read an old article on torqueing fasteners correctly. Pontiac manual says final torque on heads should be 95 ft-lbs dry.

Rotella book on rebuilding Pontiacs also says 95 but to lubricate threads and under head with 30W oil assuming use of original head bolts and studs.

Based on article, using oil as lubricant reduces torque needed by as much as 25% - 40% depending on whats used.

Anyone take into account lubricant when torqueing or do you just use manual

Question is also applicable to pan bolts, timing chain cover, etc.

  #2  
Old 03-26-2023, 11:56 AM
mgarblik mgarblik is offline
Ultimate Warrior
 
Join Date: Mar 2005
Posts: 6,035
Default

Everything you stated is correct except possibly the 95 lbs. dry. Could you tell me exactly which service manual you saw that in? I have all the chassis manuals from 1958-1975 for Pontiac and I will look at them to verify for you. It would be unusual to state dry torque specs for assembling an engine, since it's naturally oily. Generally, when nothing is stated, the factory torque specs are for fasteners clean and lightly oiled on the threads and under head. The only common exception is for lug nuts. That is a dry torque spec for them. Also, when using aftermarket fasteners like ARP, use their torque specs and their lubricants, nothing else.

The Following 2 Users Say Thank You to mgarblik For This Useful Post:
  #3  
Old 03-26-2023, 12:07 PM
dv657172 dv657172 is offline
Senior Chief
 
Join Date: Mar 2012
Location: Maryville, TN
Posts: 255
Default

1972 Pontiac Service manual states 95 lbs final torque

Good to know what is assumed when they give torque specs in the manual. Appreciate that info.

Actually manual states "Cylinder head bolts should be installed without thread sealer of any kind" so I guess thats different.

Agree on ARP comment. I was just referring to Pontiac factory hardware.

  #4  
Old 03-26-2023, 02:06 PM
Half-Inch Stud's Avatar
Half-Inch Stud Half-Inch Stud is offline
Ultimate Warrior
 
Join Date: Jul 2000
Location: BlueBell, PA or AL U.S.A.
Posts: 18,457
Default

"Dry" probably meant "moist but not puddled to cause hydro-lock". See ya gotta assure the holes are filled with oil.

let's use some sense here. Oh, I use grease on lug nuts.

The Following User Says Thank You to Half-Inch Stud For This Useful Post:
  #5  
Old 03-26-2023, 03:35 PM
dv657172 dv657172 is offline
Senior Chief
 
Join Date: Mar 2012
Location: Maryville, TN
Posts: 255
Default

To try and word the general question better....do you adjust torque specs based on what lubricant, if any, you use on thread bolts?

I never thought about this until reading an article recently that recommends a reduction in the torque based on the type of lube. Table attached.

Given the table, I would assume its important to know what lubricant, if any, Pontiac assumed when providing their recommendation on bolts.
Attached Thumbnails
Click image for larger version

Name:	20230326_094952.jpg
Views:	89
Size:	77.6 KB
ID:	609751  

  #6  
Old 03-31-2023, 10:27 PM
Joe-Touring Joe-Touring is offline
Senior Member
 
Join Date: Feb 2022
Location: Western WA
Posts: 123
Default

Lube is definitely a factor with regard to applied torque. I work on aircraft and there is a separate spec for lubed vs dry. In the same vein, there are separate specs depending on if you are torquing the head or nut side on a through bolt. (Torquing the nut is preferred)

__________________
67 LeMans, 326, M20, 3.31 12 Bolt
The Following User Says Thank You to Joe-Touring For This Useful Post:
  #7  
Old 04-01-2023, 08:13 AM
dv657172 dv657172 is offline
Senior Chief
 
Join Date: Mar 2012
Location: Maryville, TN
Posts: 255
Default

Thats interesting that there is difference depending on the bolt side or nut side. Never thought about that.

I was surprised by how much the adjustment is for a dry torque vs. one with ARP or even oil vs. ARP (see table from previous message)

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 05:13 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017