1957 exhaust donut

[NC-car-guy 3,206]

Pulled my exhaust down today to add the O2 sensor and the little donut between the manifold and the pipe fell all to pieces. I can't seem to find one listed anywhere does anyone have a part number or a size?

[Pete Phillips 2,055]

Most auto parts stores keep several sizes in stock.

[NC-car-guy 3,206]

So according to the experts, there was originally no gasket and the pipe had a "ball" shape to fit the "socket" in the manifold exit.  *eyeroll* Leave it to Buick to be complicated.  So now I essentially have two flanges that I need to seal...  I have found donut gaskets the right diameter, but they have a chamfered end and a flat end, I need one with a chamfered end on both sides...  Anyone know what that's called?

[avgwarhawk 4,444]

https://www.autozone.com/gaskets/exhaust-flange-gasket/walker-exhaust-flange-gasket-31657/278049_0_0?spps.s=2880&cmpid=LIA:US:EN:AD:NL:1000000:IEN:71700000060668281&gclid=Cj0KCQiA6Or_BRC_ARIsAPzuer8QaGX3qglgZTfgweijgn8lkPQyqm253ZLlKa0S3W5C6NaGIdhFJZUaAp3FEALw_wcB&gclsrc=aw.ds

[NTX5467 1,193]

IF the original pipes connected via a "ball joint" connection, "ball" on one side, "socket" shape on the other side, then NO gasket was needed, just tighten the two flanges with the bolts.  IF the ball has some corrosion that will not clean up with a file, then Walker makes some "muffler cement" that might fill in the low spots and seal when things are tightened.  A somewhat common way to do things, even on mid-'60s Chryslers.

 

If the ball-side is too far corroded to seal (even with the fiberous cement), then head down to the paarts store and ask for an exhaust donut for a '80s-'90s Chevy pickup.  It has a metal sleeve in the middle and 1/2 of a "soft" exhaust donut on the other side.  You'll need to know the ID of the pipe the sleeve will slide into.  This, effectively, makes a new "ball" to fit into the "socket".  Then tighten things down and all should be fine.  I did just that on my '67 Chrysler Newport 383 2bbl, as I up-sized the exhaust system a notch with a '72 Imperial y-pipe back, larger pipe, OEM exhaust system.

 

What is posted above is very similar to what I used, other than mine didn't appear to be wrapped in aluminum foil (how they look, seemingly, but are not).  That silver coating allows for the better-sealing-softer-conforming interface seal to happen, reliably.  

 

If you need a double-bevel donut, then a '69 Chevy pickup 350 V-8 used such a metal donut, but the bevels are flat rather than curved.  Not too good for sealing a rounded socket connection.

 

Just some thoughts,

NTX5467

Edited January 11 by NTX5467 (see edit history)

[NC-car-guy 3,206]

On 1/10/2021 at 7:31 PM, avgwarhawk said:

https://www.autozone.com/gaskets/exhaust-flange-gasket/walker-exhaust-flange-gasket-31657/278049_0_0?spps.s=2880&cmpid=LIA:US:EN:AD:NL:1000000:IEN:71700000060668281&gclid=Cj0KCQiA6Or_BRC_ARIsAPzuer8QaGX3qglgZTfgweijgn8lkPQyqm253ZLlKa0S3W5C6NaGIdhFJZUaAp3FEALw_wcB&gclsrc=aw.ds

Too big at 2.5"

[NC-car-guy 3,206]

On 1/10/2021 at 7:39 PM, NTX5467 said:

IF the original pipes connected via a "ball joint" connection, "ball" on one side, "socket" shape on the other side, then NO gasket was needed, just tighten the two flanges with the bolts.  IF the ball has some corrosion that will not clean up with a file, then Walker makes some "muffler cement" that might fill in the low spots and seal when things are tightened.  A somewhat common way to do things, even on mid-'60s Chryslers.

 

If the ball-side is too far corroded to seal (even with the fiberous cement), then head down to the paarts store and ask for an exhaust donut for a '80s-'90s Chevy pickup.  It has a metal sleeve in the middle and 1/2 of a "soft" exhaust donut on the other side.  You'll need to know the ID of the pipe the sleeve will slide into.  This, effectively, makes a new "ball" to fit into the "socket".  Then tighten things down and all should be fine.  I did just that on my '67 Chrysler Newport 383 2bbl, as I up-sized the exhaust system a notch with a '72 Imperial y-pipe back, larger pipe, OEM exhaust system.

 

What is posted above is very similar to what I used, other than mine didn't appear to be wrapped in aluminum foil (how they look, seemingly, but are not).  That silver coating allows for the better-sealing-softer-conforming interface seal to happen, reliably.  

 

If you need a double-bevel donut, then a '69 Chevy pickup 350 V-8 used such a metal donut, but the bevels are flat rather than curved.  Not too good for sealing a rounded socket connection.

 

Just some thoughts,

NTX5467

Got the 69 Chevy one at NAPA for $3.  Seems to fit well. Will report back on leaks.

Edited January 15 by NC-car-guy (see edit history)

[Frank DuVal 1,062]

On 1/10/2021 at 6:27 PM, NC-car-guy said:

there was originally no gasket and the pipe had a "ball" shape to fit the "socket" in the manifold exit.  *eyeroll* Leave it to Buick to be complicated. 

This ball and socket is the complete opposite of complicated. There is no gasket, just two bolts through the flanges. Sounds like someone at a later time complicated the simple OEM flange. The 70 Buick Estate Wagon had the ball and socket. Very handy as I had to disconnect it every time I replaced the clutch. So, every year or so.😲

[avgwarhawk 4,444]

11 hours ago, NC-car-guy said:

Too big at 2.5"

I have heard that before.