Exhaust slip-joint leaks

[uncltodd]

I don't know if this is common to all SB Cobra replicas or just BDR's, but the slip joints in my headers, both sides, are leaking, starting to make ugly noises, and are shooting soot all over the place.

They are spring-loaded and appear to be intact and tight.

Is there a retrofit O-ring set I can install to at least calm this problem down?

I understand why the slip joints exist, and that engine/sidepipe flex and having less than 500 miles on #139 come together to stress the joint.

Suggestions?

Sorry, Boudy, sadly, is off my screens, probably permanently.

Thanks.

UT

[Dennis Kelley]

Hey UT

I went through the same problem. I ended up wire welding my joints. I tried every type of sealer and it didn't work for me. You can tell by the exhaust marks where it is leaking. Its not a pretty fix but it works.

dennis

[TonyMadrid]

Try using High Temp Copper Silicone to seal the slip joints. I just used my finger and pushed or forced the silicaone into any gaps that were present. Once done, you can wipe any excess for a clean appearance.

Tony

[tony martin]

HI GUYS,
TRY REMOVING THE SIDE PIPES, APPLYING A LIBERAL AMT OF SILICON INTO THE INNER (SIDE PIPE SIDE) SIDE OF THE PIPES.. REFIT AND LET DRY FOR A FEW HOURS. WE HAVE FOUND THAT THIS CURES ALMOST ALL OF THE PROBLEMS U TALK ABOUT. LET ME KNOW.
REGARDS

[ENTDOC]

Will silicone hold up to that kind of heat? chuck

[CJ428CJ]

I tried the silicone and it lasted about 200 miles before it all burned away and blew out. I've also tried the various muffler seal stuff in a tube from Napa and Carquest. Those lasted longer but still only 500-1000 miles each.

I'm going to try one more thing. I'm going to reseal it with the muffler seal from Napa. After it dries, I'm going to try to wrap the joint at each of the 4 pipes as best as I can with with aluminum tape (the stuff they use to seal parts of a household furnace). To hold the aluminum tape in place I'm then going to wrap the collector in typical header heat tape.

I'm not sure what I'll do if the above fails. I'm running out of ideas.

[davidlee]

I had the same problem on my BDR. Talked to Reg ,he told me to get a tail pipe/muffler expander tool. It cost about $20.00 at the local auto parts. I removed the side pipes, expanded the header pipes to fit more snugly into the side pipes and applied a small amount or red RTV sealer. Problem solved. BTW my headers are ceramic coated.
David

[Boudy]

Yep, David is correct. The only once and for all fix is to buy a muffler expander from the autoparts store. Use a coat hanger to remove and reinstall the springs. Anything else is a true knuckle buster as well as an effort in frustration. Trust me, use the coat hanger. Remove the sidepipe and use the expander on the header pipe and reinstall.

Boudy

[jeffko]

Has anybody tried collecting the pipes into typical collectors and bolting together with gasket?

Jeff

[RodW]

Jeff,
I passed on the stock BDR headers and side pipes and had custom headers, collectors and side pipes made. The headers bolt to the collectors...... Rod

[Jack21]

Have a CR, not BDR, but here are a couple of suggestions gleaned wrestling with CR exhaust issues.

Eliminate engine movement that causes exhaust flexing by using polyurethane motor and trans mounts made by Energy Suspension. They soak up vibration and noise, but hold the engine solid so it doesn't move around. Car rocks a little with engine idling. It's this rocking and flexing of the exhaust when using standard rubber engine mounts that's making the exhaust leak. Worse, if the joint isn't allowed to flex, it will eventually break.

Support turn out exhaust exit with rubber grommet, or strap that allows side pipe some movement.

Now, your Ultra Copper may seal your joint. This stuff seals exhaust gaskets quite well. That's what it's made for.

Failing that, weld a flange connector on both ends, between J pipe and muffler, and bolt it together. Use copper gasket, and RTV to seal.

[427 S/O]

Do as david suggested, although I drove up to the local muffler
shop and had the fella do mine, we expanded in very small amounts and followed up with trial fits.

[cobrajeff]

In addition to the muffler expansion tool, I bought a few pieces of exhaust pipe reducer sections (short pieces about 6" long that go from 2.5" to 2.25", and 2.25" to 2.0" - most any auto parts store carries them). I used these pieces for trial fit (much easier and less risky than holding the pipes up to your car), and, they can be used to slightly "shrink" the opening if you go too far opening a pipe up. You can tap these onto the end of the pipe (either side, header or exhaust pipe) using a block of wood and rubber mallet to fine-tune the adjustments you made with the expander tool.

Once they fit snugly, a little hi-temp orange silicone will make it leak-proof.

regards,

cobrajeff

[CJ428CJ]

"Has anybody tried collecting the pipes into typical collectors and bolting together with gasket?"

Jeffko,

The problem with going to a typical collector type arrangement, at least on an ERA, is that each of the header tubes is a seperate piece. They need to be seperate in order to get them installed. If you connected them all to a single collector, you'd have one solid header that you'd never be able to install or remove.

Chris

[Sledge]

Folks:

I've taken off the right side pipe of my BDR with the intention of trying to get a tighter fit between the header and the side pipe (this is a slip-joint arangement). I've purchased the pipe-expanding tool, and I'm trying to do this without taking off the header.

Do you have any solvent recommendations for cleaning off the "ceramic mud sealant" that was initially used? I don't have a lot of room to work with and I don't want to foul up the aluminum ceramic finish on the headers. I've been thinking of using a wire brush where I can, and maybe flexible sanding paper "tape", but I'm afraid it will hurt the header coating and I want to avoid that.

All recommendations appreciated!

Thx

Bill

[Richard Hudgins]

Hi Folks,

Slip fit connections on headers work very well if the tube clearances are correct. I have found the following to work well.

Non ceramic coated 1.75 dia. tube. .030 total clearance inner to outer cold.

Ceramic coated 1.75 dia. tube .015 total inner to outer clearance.

Note: when assembling, coat the surfaces with standard wheel bearing grease. (I know this may sound strange, but trust me. It works well. Also works well on header to head interfaces.)