Schedule 40 pipe for trans crossmember? - 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> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 10-03-2006, 11:07 AM
Registered User
 
Last photo:
Join Date: Mar 2006
Location: Cali
Posts: 123
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Schedule 40 pipe for trans crossmember?

Hi,

I've been reading the differences between DOM tube and plain-ol black water pipe all morning and I still can't figure out if a 1.25 inch "Home Depot" steel water pipe will work as a transmission crossmember. The wall thickness is like .150" and it is made of very heavy STEEL.

Reason: I would like to add support to/or completely replace my current (weaklink) crossmember which is bolted up to the original 4-cyl tabs on the sheetmetal frame. The tabs on the frame are about 10 inches forward of the trans mount and Im not too sure about the geometry of the whole set-up.


Any input would be appreciated.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 10-03-2006, 11:49 AM
Member
 
Last photo:
Join Date: Oct 2002
Location: Lexington, Kentucky
Posts: 122
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I wouldn't go cheap here, DOM has a lot more carbon in the steel and therefore is not as easily bent. Also i see no reason square or rectangular tubing wouldn't be better. It shouldn't cost that much you only need 4-5 feet.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 10-03-2006, 11:49 AM
Registered User
 
Join Date: Oct 2006
Location: SOUTHERN OREGON
Posts: 7
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Pipe V.S. Tubing

Black pipe works, but is not a high stress rating. We use .095 wall seamless tubing for all of our race car chassis, and supports. Works quite nicely. Black pipe can do two things, Break and Bend. Neither of which is something you want to happen while going down the road. If you have some Circle Track car builders in your area, they probably have a short piece laying around that they would give you or sell at a very low price. Do not risk safety over expense.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 10-03-2006, 12:13 PM
Registered User
 
Last photo:
Join Date: Mar 2006
Location: Cali
Posts: 123
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
thanks guys. I read that Schedule 40 pipe has an approximate yield strength of 30,000 psi. I though that was more that enough to hold my trans in place! I guess there's more to it than that.

It's not that Im cheap. I just dont want to look for a steel supplier. Every time I've bought rough steel I feel that I get ripped off. I guess I'll just look for a good supplier around here.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 10-03-2006, 02:28 PM
Member
 
Last photo:
Join Date: Oct 2002
Location: Lexington, Kentucky
Posts: 122
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Is that 30,000 psi tensile, shear or compression?

The problem is if it bends, not breaks mind you, the fan hits the fan shroud, blades come off and go thru radiator, engine over heats, etc.......

saving a little money be using low grade steel on a cross-member can cost you 10-100 fold if it fails. I wouldn't do it, but then again, i'm not footing the bill either.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 10-03-2006, 02:45 PM
Henry Highrise's Avatar
Lost in the 60's
 
Last wiki edit: Removing stuck fasteners Last photo:
Join Date: Dec 2001
Location: Dixieland
Age: 69
Posts: 15,189
Wiki Edits: 4

Thanks: 0
Thanked 11 Times in 10 Posts
Well here is my thinking......galvanized pipe is to run water or air through..period. Black pipe is to run natural gas or LP gas through. Pipe is just that...Pipe. I do not consider it structural material. Go buy you some steel tubing square or round and build your cross member.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 10-03-2006, 02:56 PM
Registered User
 
Last photo:
Join Date: Mar 2006
Location: Cali
Posts: 123
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
OMG if it broke....see... I have front motor mount plates that hook up to the water pump. If that trans crossmember broke the engine would drop down onto my steering linkage that would either break the linkage off and render my steering wheel useless or completely freeze it where it is. Then the transmission would likely go all the way down to the street and my driveshaft would be found somewhere in my cabin. LoL sound horrible huh. perfect timing for Halloween.

I just convinced myself to make it out of the strongest stuff I can find. I'm strengthening the one I have now. Adding more mounting locations and more steel. can't overbuild something like that. right?

===Thanks for the sound advice.===
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 10-03-2006, 03:45 PM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,215
Wiki Edits: 0

Thanks: 17
Thanked 339 Times in 319 Posts
personally I would have made it out of heavy water pipe because of the strength issues- now you are oging to have fabrication problem due to the fact taht it does not bend easily, but if you want a test of strength, take the biggest sledge hammer to a section of that pipe adn then to a spare cross member. I say sapre because while the pipe MAY get a small dent (more than likely not though) a usual factory crossmember will get torn up. The bad thing about the pip-e is that it will not yield as much before rupturing- basically you have no warning if it will fail.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 10-03-2006, 03:46 PM
RPM's Avatar
RPM RPM is offline
World Class ASE tech
 
Last photo:
Join Date: Nov 2004
Location: Hills of TN
Age: 64
Posts: 704
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
You should have a raer support on that engine if the front is mounted at the water pump. You need a mid mount. You don't need to find a big steel supplier to find small pcs of steel. There should be some kind of a fab shop around and they will sell you what they call drops for next to nothing.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 10-03-2006, 04:28 PM
Registered User
 
Last photo:
Join Date: Mar 2006
Location: Cali
Posts: 123
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I've been thinking about another engine mount. But my Vega has absolutely no room to fit standard motor mounts. As long as the trans is kept up- I don't see how the front mounts made from 1/4" plate can fail. Don't many very high horsepower setups have these type of mounts? They are the Hooker mounts that get bolted to the waterpump and the 4 holes on the lower front of the block.

The trans mount that comes with the set is garbage. It bolts the trans to a very thin part of the floor. Even my current setup is better than that. Plus it didn't give me the right driveshaft angle. So thats why I am where I am.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 10-04-2006, 06:08 AM
Tbucit's Avatar
Registered User
 

Last journal entry: Kinda showing off
Last photo:
Join Date: Mar 2006
Location: Conyers GA
Posts: 75
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Ap's post

Just wanted to make a quick note about his post. The "hammer" test is NOT a recognized standard in the industry. Even if a piece of black pipe will not dent as much as a square or rectangular tubing it doesn't mean that it is stronger. Black pipe should never be used for ANY structural member on a street car (mounts, cross members, frames etc). I am all for scrounging to make the pieces I need but nobody wants to have a car that has the constant potenial to come apart at any time. A few dollars or some good scrounging will provide anything you would need.
BTW There is no need to use DOM (Drawn Over Mandrel) tubing (the most expensive) for this project. Seamless tubing would be excellent and a good heavy wall welded tubing is more than enough.
This time this is not an opinion but the facts LOL
One quick thing most of the front plate mount engines also have a plate at the bellhousing area to hold the end of the engine.


Randall

Last edited by Tbucit; 10-04-2006 at 06:15 AM. Reason: Adding something
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 10-04-2006, 06:35 AM
Lonestar's Avatar
"May the Schwartz be with you"
 
Last wiki edit: How to rebuild an engine
Last journal entry: Finally getting going...
Last photo:
Join Date: Aug 2004
Location: United States
Age: 44
Posts: 1,054
Wiki Edits: 1

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by VEGA 3503508.5
I've been thinking about another engine mount. But my Vega has absolutely no room to fit standard motor mounts. As long as the trans is kept up- I don't see how the front mounts made from 1/4" plate can fail. Don't many very high horsepower setups have these type of mounts? They are the Hooker mounts that get bolted to the waterpump and the 4 holes on the lower front of the block.

The trans mount that comes with the set is garbage. It bolts the trans to a very thin part of the floor. Even my current setup is better than that. Plus it didn't give me the right driveshaft angle. So thats why I am where I am.
If you run only a front motor plate and a trans mount, you are leaving a long length unsupported. This stresses the tranny bellhousing which may lead to separation from the engine at a most inopportune time. The mid plate solves this issue.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 10-04-2006, 06:37 AM
Member
 
Last photo:
Join Date: Feb 2005
Location: West Michigan
Posts: 307
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I have never used pipe but I don't think you would ever have a problem.
The thought of using it just doesn't seem like a good idea. For what little tubing you would need, I don't see much of a cost difference. That being said the black pipe would probably be stronger than the flimsey tubes in some of the crossmember kits you can buy. I agree with the above post. You should have a mid plate.
Bob
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 10-04-2006, 05:15 PM
Registered User
 
Join Date: Jul 2006
Location: Texas
Posts: 97
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
pipe

Go to a plumbing supply store and order some schedule 80 pipe. Dont go cheap!
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 10-04-2006, 09:06 PM
Glennk's Avatar
Registered User
 
Join Date: Mar 2002
Location: Las Vegas Nevada
Age: 77
Posts: 72
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
pipe

Every time I read about using pipe for something on a car, on this site I read all these misconceptions about pipe. Pipe is just as strong as mild steel tube of the same approx. size. The only difference is the size and finnish..Pipe is rolled rough finnish . I would not be afraid to use pipe...as far as breaking, thats BS....Of course it doesn't look as nice but thats your decision...GlennK
Reply With Quote Quick reply to this message

Recent Engine 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:
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
Exhaust Diameter Formula ChevelleSS_LS6 Engine 11 04-27-2012 09:21 PM
air lines CARGUY Garage - Tools 96 11-16-2006 04:11 PM
Sanding "bondo" with 40 or 36 a No-No! MARTINSR Body - Exterior 44 05-15-2006 09:32 PM
Airlines Kevin45 Garage - Tools 22 03-04-2004 04:35 AM
Is 2 1/2 pipes big enough? Mustang_Killa66 Engine 7 02-12-2004 08:04 AM


All times are GMT -6. The time now is 07:55 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.