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?
Full Version: Stub pipes
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.
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.
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.
When you torque up the heat exchangers do you tighten them in increasing values in a pattern like lug bolts?
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.
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.
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. 
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.
Seen this more than once.
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
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
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=
http://www.914world.com/bbs2/index.php?sho...c=36548&hl=
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.
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.
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.
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.
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