Slip-fit collectors - How do I get them to seal?

[dhardison]

I'm using Dynatech headers which utilize slip-fit collectors. They fit well and all, but leak badly around the collector/pipe connections. Anyone have any ideas how to seal slip-fit collectors?



I've tried squeezing a thick bead of Loctite RTV 5920 Copper Silicone gasket maker inside each collector tube before slipping them on but it only lasts about 50-75 miles before burning/blowing out. Any other thoughts/products out there that might help?

Thanks!

[Rick Dorion]

Dan, have you tried the band clamps?

[dhardison]

Dan, have you tried the band clamps?

Hmmm, not a bad idea. Only problem is that I'd have to grind off the existing mounting tabs. Do they make 2-1/8" diameter band clamps?

[whytry]

I thought the slip-fit collectors were supposed to use the donut style gasket, I was looking at converting to these as well, ground clearance issues......

[Rick Dorion]

I think you may be thinking of the ball/cone style.

Dan, I've used 2 1/2 and 3" ones like these:

http://static.summitracing.com/globa...702500_w_m.jpg

[dhardison]

Dan, I've used 2 1/2 and 3" ones like these:

http://static.summitracing.com/globa...702500_w_m.jpg

Thanks Rick. I found some 2" diameter band clamps that 'might' work on my 2-1/8" tubes.

[Rebird]

did the band clamps work? i just bought a set of the same headers. thanks
p.s... how is the ground clearance? nice motor!!

[Samckitt]

Not sure if it will work, but check ebay auction 320112522537

Or, I used this style on my 3" dual exhaust, check ebay auction 120111280357.

[dhardison]

did the band clamps work? i just bought a set of the same headers. thanks
p.s... how is the ground clearance? nice motor!!

Thanks! Unfortunately no, there's just not enough room between the tubes on the collector for band clamps. For now I'm back to spreading a thick layer "copper" Permatex inside the collector tubes, then when I slide the collector on the header it seals against the tubes - for a while, then it burns/blows out. My only other choice is to use 'exhaust paste', but the problem with that is it hardens permanently and I don't want that. In order to remove the driver's side header I have to be able to remove the collector and separate the header (or pull the engine).

For ground clearance comparison, the only other header with which I can compare is Hooker Super Comps. The Dynatech header is much tighter to the floorboard and provides a good inch additional ground clearance vs. the Hookers.

[dhardison]

Not sure if it will work, but check ebay auction 320112522537

Or, I used this style on my 3" dual exhaust, check ebay auction 120111280357.

Thanks Scot. Unfortunately I just can't squeeze those between the collector inlet tubes. I'm using those band clamps elsewhere on my exhaust and they work very well.

[Rebird]

Bummer..... i'll let you know if i find any fixes that are not perminant. thanks for the info and nice car!
p.s... how tall is your intake on the 572? it looks like it will clear the cowl hood with no problems. thanks

[Rick Dorion]

Does dynatech have an opinion on the leakage. Seems the design could use a split end with welded clamps already on that you could tighten.

[dhardison]

Does dynatech have an opinion on the leakage. Seems the design could use a split end with welded clamps already on that you could tighten.

Although the headers are of good quality, I can't say the same for Dynatech's customer service. I've called and received the usual "I'll check with so-n-so and call you back", only never to receive that call-back. When I call back, I get the run-around.

The split-end with welded clamps is a good idea.

[BobB66SS]

I had ground clearance issues with my Hooker header flanges so I cut them off. Installed the slip fit adaptors between collector and 2.5" exhaust and used the wide stainless band clamps that come with a layer of dynamat-like material at the joint. To help with the leak issue I also put a layer or two of header tube heat wrap at each seam. Seems to be working well so far.

[paul67]

What about expanding the hedder tubes ,I've used a socket it only needs to be the end just to make it that bit tighter then spread the copper on after.

[dhardison]

What about expanding the hedder tubes ,I've used a socket it only needs to be the end just to make it that bit tighter then spread the copper on after.

Thanks and not a bad idea, but the collectors are already a bear to get on and off. Surprising really, considering the amount of exhaust that spews from the joints.

Last time I put a nice thick bead of copper RTV down inside the collector tube, in hopes that when the tubes bottomed out in the collector the RTV would seal things up. Instead I think the RTV was pushed out by the header tubes in to the collector where is was blown out by the exhaust. Next time I'm going to entirely coat the inside of each collector tube with a nice even coat of RTV in hopes of sealing the entire tube mating surface vs. just the end.

[dhardison]

I had ground clearance issues with my Hooker header flanges so I cut them off. Installed the slip fit adaptors between collector and 2.5" exhaust and used the wide stainless band clamps that come with a layer of dynamat-like material at the joint. To help with the leak issue I also put a layer or two of header tube heat wrap at each seam. Seems to be working well so far.

I use those stainless band clamps on the large 4" end of the collector as well. They work great. My exhaust leaks are where the four individual header tubes insert in to the four collector tubes. It's just too tight to get any sort of small band clamp or wrap in there.

[dhardison]

Bummer..... i'll let you know if i find any fixes that are not perminant. thanks for the info and nice car!
p.s... how tall is your intake on the 572? it looks like it will clear the cowl hood with no problems. thanks

I'm not sure of the actual 572 intake height measurement, but it does clear my 2" cowl (with a little over 1" to spare), when using a 14x4 air cleaner and 1.5" drop base.

[jasonsnova]

dan, next time try the red rvt its the high temp stuff, on out race cars we used to use it for a header gasket(head to header) and it holds up. but that with open headers with no back pressure

[paul67]

How long have you run the engine as you might find over time ie a week that they seal up, also what make you think there leaking , can you see hear or feel some thing , as mine are showing soot as the engine not been running much but feel no exhaust.