? bolt stretch????????? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Hotrodding Basics
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 06-06-2007, 07:28 AM
Registered User
 
Join Date: Mar 2006
Location: WI
Posts: 347
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
? bolt stretch?????????

I put my oil pan on along with intake and valve covers last fall. I had to take the oil pump back off to repaint it do to moros and their crappy paint job. when i went to take out the bolts they were quite loose almost no effort to take them out. so i went around and double checked everything else while i was at it. they were all loose or atleast needed to be tightened. the bolts i used are ARP's polished stainless bolts. did these bolts stretch and is that why they need tighted? The motor has never been installed yet just sat in storage and the bolts were loose. If its not bolt stretch then what could it be? I dont want to have issues if they come loose again once the motor is in and end up with leaks.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 06-06-2007, 08:08 AM
crash70rs's Avatar
Member
 

Last journal entry: Going Slow.. and steady?
Last photo:
Join Date: Aug 2003
Location: Rochester, NY
Age: 30
Posts: 161
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Did it have a cork type gasket? If so the gasket may have shrunk in storage.
The bolts should not "creep" (elongating from a load, i.e. being tight) at all. A least I wouldn't think so.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 06-06-2007, 11:04 PM
curtis73's Avatar
Hates: Liver. Loves: Diesel
 
Last wiki edit: How to find cheap parts
Last journal entry: 1999-2001: Getting it on the road
Last photo:
Join Date: Dec 2005
Location: Carlisle, PA
Age: 40
Posts: 5,148
Wiki Edits: 16

Thanks: 0
Thanked 4 Times in 4 Posts
That's very typical. The oil pan and valve covers are made from wimpy stamped steel so you can't torque them like other bolts. What would happen is the stamped steel would deform and compress the gasket just under the bolt which would cause massive leaks between bolts. The secret to getting them to seal is to just snug them so the stamped steel remains flat and provides unifom pressure along the rail. When the gasket relaxes it often means loose bolts.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 06-06-2007, 11:17 PM
Blazin72's Avatar
You got a leaky spark tube...
 
Last wiki edit: Rearend removal
Last journal entry: General Lee
Last photo:
Join Date: Jul 2005
Location: Union, WA
Age: 32
Posts: 2,868
Wiki Edits: 19

Thanks: 0
Thanked 2 Times in 2 Posts
A bolt will stretch while tightening it. That is what causes the tension to hold the component in place. This is what you are accomplishing when you are torquing a bolt, using a predetermined force (torque) to set bolt stretch (and therefore tension). However, a bolt should not continue to stretch any more once you've stopped torquing it. It should hold its tension. Over torquing, fatigue, vibration, the gasket relaxing or component deformation (both as previously mentioned) could be causes for a bolt to loosen.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 06-07-2007, 09:05 AM
Registered User
 
Join Date: Mar 2006
Location: WI
Posts: 347
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I have edelbrock's aluminum valve covers i know they arent flexing thats why i bought them so i could torque the crap out of them and not pull or stretch the metal. The oil pan is fairly thick and i daw no sign of mushrooming around the holes. so it must be the cork gaskets i used relaxing or shrinking. hopefully they are done doing that now that i torqued the heck out of all the bolts again. even my intake was loose but not the water pump so it must have been a gasket thing. thanks guys that awnsers alot.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 06-07-2007, 06:15 PM
Member
 
Last photo:
Join Date: May 2003
Location: Shreveport LA
Age: 64
Posts: 5,103
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Cork gaskets shrink, especially early on in their life. I always re-tighten mine after a week or two, then again after a few months. Check them again after a year or so just to be sure.

This assumes the engine is being run fairly regularly. Yours probably did the first weeks worth of shrinking while it was just sitting in storage.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 06-07-2007, 08:29 PM
Vortech 4.3's Avatar
jack of all trades
 
Last photo:
Join Date: Dec 2005
Location: sw sub chicago
Posts: 780
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by tinman386
I have edelbrock's aluminum valve covers i know they arent flexing thats why i bought them so i could torque the crap out of them and not pull or stretch the metal.

you don't know much about aluminum.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 06-07-2007, 10:16 PM
Ambassador of 'Pane's Avatar
Envirominded hotrodder
 

Last journal entry: Stupid broken leg
Last photo:
Join Date: Jun 2007
Location: Granite Falls, WA
Age: 35
Posts: 85
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I agree it is probably the cork gaskets, but you are also right that SS bolts stretch. They are just fine for things like valve covers and oilpans, I'm using SS screws for just that as well, but stainless steel doesn't have enough carbon in it to be tempered and hardened and are therefore comparable to a grade 2 bolt.
Reply With Quote Quick reply to this message

Recent Hotrodding Basics posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
the history of chevy v8's savman1 Hotrodders' Lounge 43 03-02-2012 06:57 PM
Chevy 350 Crankshaft bolt removal 75gmck25 Engine 11 03-14-2008 06:27 AM
rod bolt stretch (poll) engineczar Engine 29 05-27-2005 09:49 PM
Stretch bolt gauge ? bowtieorbust Engine 6 06-19-2004 11:25 AM
10 bolt to 12 bolt 1980Impala Transmission - Rearend 8 04-25-2004 04:48 PM


All times are GMT -6. The time now is 12:07 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.