On my 76 f250 Supercap the donut gaskets that are between the headers and the exhaust pipes keep blowing out. What could be casing this? and what can i do to fix it? when one blows out people look at me like i am crazy driving around town . 2WD 351m c6 long bed

 

Are you getting any grease or oil on them (the donut) before you install? Maybe instead of the standard parts store, try a speed shop with some high temp quality ones?

 

Are you talking about the flat gaskets that go between the collectors and exhaust pipe? Or are you talking about a donut gasket which is a whole different thing?

 

The doughnuts are made of sintered metal and can crack and fail if the joint is over-tightened or the downtube is misaligned.... ask me how I know.

 

I cant believe this has taken so long. All together now. HIO...how do you know! Sorry couldnt resist ha ha ha.

 

Its the flat gasket between the collectors and the exhaust pipe. There is a lot of oil in that area. Could the oil be affecting the gaskets?

 

Summit copper gaskets...

A guy said this...I don't use header gaskets any more, haven't for about 4 years and have had no failures on several Cobras as well as 2 428CJ Mustangs. I use Permatex High temp(copper) gasket maker. It is important that both surfaces be clean and oil free. I apply it on the header evenly but not too thick and then hand tighten the header bolts so they have some light compression on the sealant. I then allow it to set up(cure) overnight, sometimes a day or so if I'm doing other work, and then tighten the bolts to torque. It works great and eliminated the problem I had on my 351 Cleveland with having to replace one or the other gaskets every 6 months or so.

Also I hear that soaking the gasket in water to soften it before you bolt it up will help seal. And making sure both surfaces are flat as can be and grease and oil free.

I hear oil can speed up the burn out process.

 

... a 44-year old exhaust manifold, original down pipe, rusted studs, and yes, a "previous owner" who was a hack.

Jeez... terminology bites again.

This is a "donut" gasket. In other circles a "sealing ring".

 

Its like this one.
Walker Exhaust Gasket 31571: Get best Exhaust Pipe/Flange Gasket at Advance Auto Parts

 

I have used copper and aluminum collector gaskets and I had to tighten one, one time is all and it sealed right up again. Yes oil and grease can be very tough on fiber type gaskets like the ones you showed. Plus, make sure your exhaust system is not too rigid. The first hangers should be back towards the axle so when the motor torques it will flex the exhaust pipe and headers slightly instead of just the joint. I had that problem with some ball type collectors. Even with the hangers back there they would not stay tight for more than a few weeks..

 

Hope I didnt get you to bent out of shape Hio, all in jest. I was going to use a line out of Grease but was afraid too many wouldnt catch on. I've screwed up those donuts myself by over tightening and wound up cracking, crushing it. When he wrote donut I thought donut, I've spent to much time at Tim Hortons. As for terminology, a few years back I went to do an estimate to install 60' worth of exposed aggregate curbing. The ahole really meant a 9' x 60' retaining wall. Have a goodnight.
P.S. showed that dentside roadster to a friend and he thinks thats a good use of a parts truck.