gasket between headers and side pipes

[Mike Simard]

I like the copper too. Byson sounds great but these flanges have such a small area between holes that solid copper might hold up better. I can email someone a DXF file of the geometry. I came close to making these myself and have the dimensions in a CAD file.

[dvcobra]

I just finished running at SAAC 30 and will be back from vacation Sunday. For those of you interested I will e-mail you when I get back. The copper gaskets are $30.00 pr. which includes shipping.
They are made from extreme temperature copper alloy 101. I ran them all weekend at the track plus the previous several months. They are working great. A CAD file of the pattern should work, I will verify with my assistant that handles the programing on the router.

[Mr.Fixit]

With those copper gaskets, if you remove them, do you need to re-anneal them prior to installing them again?

[Don]

DV Cobra

I received the gaskets today, excellent fit to the extra flange that I had, + or - 0.000001. Plan to keep the gaskets in the Cobra ( just in case ) along with extra bolts until I have the opportunity to install.......

Same topic, I contacted ARP concerning the bolts for securing the primaries to the side pipes, no reply. What bolts are you using, w or w/o lock washers or Loctite ?

..........thanks !!!!!

Don

[dvcobra]

I am still experimenting with the bolts. I went back to the grade 5 bolts (grade 8 gets brittle and snaps) on one side and I am trying Military grade stainless steel on the other. I haven't checked yet to see which one is holding up better but both are working and went through the weekend of racing at SAAC. I have tried several types of lock washers and the jamb nut over the years and all vibrated loose. The only thing that has worked for me are the lock-nuts with the crimped top (don't remember the name of them). Another thread recommended A-286 bolts but I have not been able to find those.

[Mr.Fixit]

Grade-5
use flat washers, but not lockwashers.
Nylon locknuts will not work.
Prevailing torque locknuts will (oval ended), but will be a pain to put on.

Throw away the bolts and nuts EVERYTIME you remove them, use fresh ones!!!!

[trularin]

I am using military SS HEX heads and lock washers.

Can't use the "Prevailing torque locknuts" as they are a pain.

[Tommy]

I'll add my personal anecdote just in case someone finds it useful. After rebilding my 351W with aluminum heads, the stainless steel headers on one side leaked after a few hundred miles of use. When I replaced the gasket, I added a generous bead of silcone sealant. I now know that the relatively low torque on the header bolts combined with the thick sealant to allow the headers to stand out from the face the heads. When I started running the engine, the headers rocked back and forth on the bead of sealant and quickly began to leak.

Faced with headers that leaked with two different gasket/sealant combinations, I investigated further. I took the headers to my local machine shop and asked them to check the mounting surface for flatness. Sure enough, the mounting surface was warped. I had them mill the surface flat and remounted the header with a normal gasket, normal torque and safety wired bolts. It hasn't leaked since.

[Don]

Trulian.....do you have a web site or phone number for ordering the " military SS HEX heads ". When mentioning to the local hardware stores, Home Depot, etc., they had no knowledge of the product

Don

[RallySnake]

Hey Guys,

I used Mr. Gasket 3/8" header bolts with the 7/16" bolt heads. These are easy to get a socket on in tight areas. I also welded nuts to the backside of the header flange so I wouldn't have to use a wrench to hold them. This setup works pretty well and is easy to take apart.

Paul

[FUNFER2]

It's sad to see so many problems with leaking gaskets. I really like the ARP stainless steel studs.........not bolts, Felpro header gaskets and use high temp silicone. Easy with the silicone, just a 1/8" bead is fine. Apply silicone to the header flange, place the gasket on top, put bolts in to hold the gasket centered. Leave over night if you can. Next, put a small bead of silicone around each cylinder tube, place the header over the studs, put the nuts on every stud, tighten them equally. After a nice couple of cruises, re-tighten all the nuts. To me, bolts are a pain. Try using studs. With my FE in a cobra, I only have two holes that I can't use a stud so, the two bolts are last to go in. I haven't had a leak yet..........thankfully.

[dvcobra]

I got my Military spec stainless bolts and locking nuts at McMaster-Carr, get a catalog. They have well over 500 pages of everything you can't live without. Go to "www.mcmaster.com" you will be amazed!

[Byots]

nm .

[Ron61]

For sealing my side pipes into the collector which is not like the original 4 into 1 configuration, I got two 4"wide stainless clamps that are like bands. I just slip them on and put the side pipe in and then slide them down until they cover the pipe and collector joint and tighten them. Have never had a leak and have taken them off many times. But bear in mind that I replaced the 4 lead tubes with one 4" diamater elbow joint which seemed to really give me better exhaust flow.

Ron

[Byots]

nm .

[Widows Son]

Resurrecting the thread since my question builds off some past questions raised here and on similar side pipe / exhaust / gasket threads.

My Backdraft driver’s side side pipe bracket which floats on a rubber bushing broke near the pipe – likely due to lots of vibration and tension. I took the pipe off had a new stainless bracket welded back on. Much more robust than the original and had them bend the bar at an angle so the pip was not bent too far down. I’ve show some pictures here. But my question has nothing to do with the bracket…

I removed the side pie to facilitate welding and in doing so noted that the top of the exhaust /side pipe gasket had blow by. The car has only 1,900 miles. It did not look serious and am not too concerned. The fit of the flanges do look fairly square and flat around the perimeter. VMS has sent me another gasket (Thanks Jay) and I’ve ordered new grade-8 bolts and nuts even though the ones removed look fine. After reading the above info and noting some time has passed since the above, here’s my questions:

Since I will use the gasket, should I ALSO use the high temp RTV (shown) or not? If so, I assume both sides of the gasket, correct? Thanks for the feedback.

New Bracket with slight bend to raise the pipe:


Side Pipe Flange (Pic was rotated so top of pipe is top of picture). Shows where the blow by is occurring:


One side of the gasket:


Other side:


More pictures of the gasket:

[mike harter]

I also would be interested in the copper gaskets. Get me the info. Thank you Mike

[Z-linkCobra]

Originally Posted by Buzzmobile

I have a SPF and need to get this gasket. Is there a stock number or is this something I need to get from them directly? I did use the old torn up one to do a "make your own gasket" out of exhaust gasket material but that has not been totally successful, but I am driving the car

But now it is time to hunt down the exhaust leaks and put the thing back correctly. Have you guys ever made any custom copper gaskets for this before? If so, how did it work out and how what did you use? Any ideas are welcome.

thanks
Buzz

Buzz,

I didn't read the whole thread so if this has been suggested sorry for the repeat. I built my own headers and side pipes for my EM. I had a machine shop cut out flanges with a water jet cutter. At the same time I also had them cut out copper gaskets. I think I used .060 copper sheet. After everything was welded up I took my headers to another machine shop with the old style belt sander for surfacing heads. Had them run the flanges on the headers and the side pipes on the belt and that got them good and flat. Bolted them together with the copper gaskets with no silicone or anything. They don't leak at all.

If you have the old gasket you can take it to a shop with a water jet cutter or cnc plasma and they do you up some. Just a suggestion. Keep in mind the first set will be a little costly because of the CAD work to lay it out. After that its the cost of the material and cut. I have my own CAD program so I do my own CAD work and that saves me money. If you know someone who has a CAD program you can save some money. Its a simple layout so it shouldn't be much.

Looking at your pics your flange is likely not flat. You likely have a low spot where its blowing. You can use a large long bastard file on the flanges if you don't want to pull the headers.

Gene

[Widows Son]

Hold the fort all and sorry for the confusion. All posts pre#36 are from 2005. . I wanted to resurrect this 2005 thread because it raised some good ideas around RTV. After 9 years since the thread was last posted, I was looking for feedback on my questions on post #36 above. Thanks.

[RET_COP]

No Gaskets, No leaks. They need to mate perfect. I filed them flat and matched them. Also when I went to 3" mufflers with less back pressure that really helped.