 Stub pipes, Better? |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
  |
| jeffdon |
 Jul 10 2016, 10:52 AM
Post
#1
|
|
Senior Member  Group: Members Posts: 1,094 Joined: 24-October 06 From: oakland, ca Member No.: 7,087 Region Association: None  |
Been fighting exhaust leaks on my 2 liter. Running SS exchangers. And yea, I anneal the copper gaskets. And have taken a large file to the pipe ends to get them on the same plane.
MY question is regarding stub pipes. Are they any easier to seal than standard exchangers? I have some old steel exchangers, and am thinking I can make drop tubes from them by cutting the ends off, and adding a flange. Then cut my SS exchangers and add matching flanges. Or maybe flare one side and do a compression fit. What do all ya'll think? |
   |
 
|
| barefoot |
Jul 10 2016, 11:29 AM
Post
#2
|
|
Senior Member Group: Members Posts: 1,273 Joined: 19-March 13 From: Charleston SC Member No.: 15,673 Region Association: South East States 
|
Adding two more leak points just doubles chances of a leak.
Also, how square and exactly same length of stub tubes are makes a huge difference in chances of fitting properly. Also squareness of new flanges on old exchangers is also important. If you could machine things square and equal length after welding, you'd have a chance. |
|
|
|
| 914forme |
Jul 10 2016, 12:11 PM
Post
#3
|
|
Times a wastin', get wrenchin'! Group: Members Posts: 3,896 Joined: 24-July 04 From: Dayton, Ohio Member No.: 2,388 Region Association: None
|
Stubs work out great, if you buy the proper system. Tangerine Racing headers have a flange on the stubs that seal with carbon after a bit of run time. What it allows is bolting up the stub, then bolt up the header. Reduces the chances of leaks. That being said yu get what you pay for, Chris' work is impeccable, expect to pay the price for an artists work.
|
|
|
|
| rhodyguy |
Jul 10 2016, 12:33 PM
Post
#4
|
|
Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,079 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
When you torque up the heat exchangers do you tighten them in increasing values in a pattern like lug bolts?
|
|
|
|
| Mark Henry |
Jul 10 2016, 01:08 PM
Post
#5
|
|
that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
I'll say no....because of a few things...
To get it long enough to bolt to the stubs you will have to lower the whole exaust system by at least an inch. By that time you do get low enough you are into the bend, creating all kinds of headaches. Then you have to mod the bottom tins. Often on the SSI's it's the ears that are bent or broken from someone over torqueing them. You need to heat and straighten them and then weld cracked and/or broken ears. Once this is done you have to true up the ends. When installing use washers under the nuts and don't over torque them. |
|
|
|
| MartyYeoman |
Jul 10 2016, 01:19 PM
Post
#6
|
|
Senior Member Group: Members Posts: 1,518 Joined: 19-June 03 From: San Ramon, CA Member No.: 839 Region Association: Northern California
|
I've had trouble in the past with the ears contacting the head before the copper gasket completely seated/sealed. Take a look there and file the ears back a bit if needed. (IMG:style_emoticons/default/sawzall-smiley.gif)
|
|
|
|
| aircooledtechguy |
Jul 11 2016, 09:14 PM
Post
#7
|
|
The Aircooledtech Guy Group: Members Posts: 1,966 Joined: 8-November 08 From: Anacortes, WA Member No.: 9,730 Region Association: Pacific Northwest |
QUOTE(Marty Yeoman @ Jul 10 2016, 12:19 PM)  I've had trouble in the past with the ears contacting the head before the copper gasket completely seated/sealed. Take a look there and file the ears back a bit if needed. (IMG:style_emoticons/default/sawzall-smiley.gif) (IMG:style_emoticons/default/agree.gif) Seen this more than once. |
|
|
|
| Dave_Darling |
Jul 11 2016, 10:52 PM
Post
#8
|
|
914 Idiot Group: Members Posts: 14,985 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California
|
Stub pipes are great if you're running a system that was designed with them in mind. You leave the stubs bolted on full time, and with the right joints between the stubs and headers you can increase your odds of a leak-free setup.
But it would be the wildest coincidence if they would even fit heat exchangers at all! It might be possible to make significant modifications to the head ends of the heat exchangers so that they will work with stub pipes, but it will be a whole lot of work. If you really want that, then talk to Racer Chris. He has header setups that are made for stub pipes, which he also makes. --DD |
|
|
|
| Dominic |
Jul 12 2016, 02:39 PM
Post
#9
|
|
Dominic Group: Members Posts: 992 Joined: 14-January 03 From: Vacaville, CA Member No.: 149 Region Association: Northern California |
If you want to see some pics of CFR stub pipes and headers, here is a link to an old thread I started: (Artwork that you install on your 914)
http://www.914world.com/bbs2/index.php?sho...c=36548&hl= |
|
|
|
| 914_teener |
Jul 12 2016, 06:37 PM
Post
#10
|
|
914 Guru Group: Members Posts: 5,197 Joined: 31-August 08 From: So. Cal Member No.: 9,489 Region Association: Southern California |
QUOTE(Mark Henry @ Jul 10 2016, 12:08 PM) I'll say no....because of a few things... To get it long enough to bolt to the stubs you will have to lower the whole exaust system by at least an inch. By that time you do get low enough you are into the bend, creating all kinds of headaches. Then you have to mod the bottom tins. Often on the SSI's it's the ears that are bent or broken from someone over torqueing them. You need to heat and straighten them and then weld cracked and/or broken ears. Once this is done you have to true up the ends. When installing use washers under the nuts and don't over torque them. (IMG:style_emoticons/default/agree.gif) Also I take some high temp sealant...the stuff that is infused with copper and with your finger make a bead after the copper gaskets are in. |
|
|
|
| 914_teener |
Jul 12 2016, 06:37 PM
Post
#11
|
|
914 Guru Group: Members Posts: 5,197 Joined: 31-August 08 From: So. Cal Member No.: 9,489 Region Association: Southern California |
QUOTE(Mark Henry @ Jul 10 2016, 12:08 PM) I'll say no....because of a few things... To get it long enough to bolt to the stubs you will have to lower the whole exaust system by at least an inch. By that time you do get low enough you are into the bend, creating all kinds of headaches. Then you have to mod the bottom tins. Often on the SSI's it's the ears that are bent or broken from someone over torqueing them. You need to heat and straighten them and then weld cracked and/or broken ears. Once this is done you have to true up the ends. When installing use washers under the nuts and don't over torque them. (IMG:style_emoticons/default/agree.gif) Also I take some high temp sealant...the stuff that is infused with copper and with your finger make a bead after the copper gaskets are in. |
|
|
|
|
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 14th May 2024 - 05:50 AM |
Invision Power Board
v9.1.4 © 2024 IPS, Inc.