53-55 Exhaust donut sleeve

[Troy P.]

On page 61 in the Corvette Central catalog it show a drawing of part 322118, a sheet metal sleeve that goes inside the exhaust manifold and seals to the top of the fiber packing donut. The catalog indicates it fits 53-62. Was this part used in 53, 54, and 55?

The 53-55 parts book has a 6 cyl gasket flange 2 1/32" ID 3692831, quantity 1, listed and a V8 2" ID gasket flange 3711569, quantity as required, listed. Could these be those parts?

Interestingly the same parts book lists a packing donut for the 6 cyl but none for the V8.

[Mike E.]

Re: 53-55 Exhaust donut sleeve

Don't know that it was used beyond 55 either!

[Scott K.]

Re: 53-55 Exhaust donut sleeve

The sleeve was originally included in the manifold. The replacement sleeve needs to be pressed into the manifold, then positioned into place, followed by the donut. When correctly positioned, the sleeve will protrude slightly from the donut. I'll look for an example image.

[Troy P.]

Re: 53-55 Exhaust donut sleeve

I'd appreciate that. I don't recall ever seeing this part before.

[Chris S.]

Re: 53-55 Exhaust donut sleeve

I have over a dozen original manifolds
I have never seen one pressed in.........

[Troy P.]

Re: 53-55 Exhaust donut sleeve

Does your 57 have one? I'm pretty confident as well that they are not a 6 cly. part but I'm wondering if 55 and up V-8's might have them.

[John H.]

Re: 53-55 Exhaust donut sleeve

Troy -

That sleeve (called an "extension") didn't appear in the A.I.M. as a separate part until 1966. Prior to '66, it may have been part of the front exhaust pipe - I've seen pipes that had it as an integral part of the pipe. Without it, the packing would disintegrate in short order.

[Troy P.]

Re: 53-55 Exhaust donut sleeve

Thanks for your info, John. Since I have a 55 Corvette to restore I'd still like to find out if it was used in that year.

When I restored a 55 Chevy Sports Coupe years ago I did not use one. But then again that may have been out of ignorance.

[John H.]

Re: 53-55 Exhaust donut sleeve

Troy -

The beveled edges of the packing match the angles on the manifold outlet (or the heat riser valve) at the top and the flange on the exhaust pipe on the bottom, and when the stud nuts are tightened, those angles force the entire circumference of the packing inboard; the "extension" supports the inside diameter of the packing and prevents it from crumbling/disintegrating into the exhaust stream. Whether it's an integral welded part of the pipe or a separate part inserted into the end of the pipe, it's required for durability of the packing and freedom from exhaust leaks.

[Troy P.]

Re: 53-55 Exhaust donut sleeve

Makes sense to me. Seems like this would happen with the 6 cyl. set up as well. So do you think there should be two on that car as well?

[John H.]

Re: 53-55 Exhaust donut sleeve

Makes sense to me. Seems like this would happen with the 6 cyl. set up as well. So do you think there should be two on that car as well?

Troy -

I'm not familiar with the six-cylinder split manifold, but if they have packings, I'd think they also have the "extensions" to prevent the packings from crumbling.

[John S.]

Re: 53-55 Exhaust donut sleeve

Troy -

The beveled edges of the packing match the angles on the manifold outlet (or the heat riser valve) at the top and the flange on the exhaust pipe on the bottom, and when the stud nuts are tightened, those angles force the entire circumference of the packing inboard; the "extension" supports the inside diameter of the packing and prevents it from crumbling/disintegrating into the exhaust stream. Whether it's an integral welded part of the pipe or a separate part inserted into the end of the pipe, it's required for durability of the packing and freedom from exhaust leaks.

1955 uses gaskets. i have the early and late manifolds and heat riser combinations and both sides use gaskets. there are no bevel edges on a 55 heat riser or exhaust manifold. there is next to no clearance between the exhaust manifold and the heat riser gate as it opens. no way was there ever a donut, it would interfere with the gate.

[Greg G.]

Re: 53-55 Exhaust donut sleeve

I may be wrong but I think the sleeve was pressed into the exhaust pipe and not the manifold.

This may be only for the six cylinder cars in 55 and all for the 53 and 54. I think there were just a few six cylinders Vettes in 55 (like maybe 5).

[John S.]

Re: 53-55 Exhaust donut sleeve

Thanks for your info, John. Since I have a 55 Corvette to restore I'd still like to find out if it was used in that year.

When I restored a 55 Chevy Sports Coupe years ago I did not use one. But then again that may have been out of ignorance.

troy, your car will use gaskets, no donuts. for car #1074 your exhaust manifolds should both be undated. on the driver side the manifold number will be 3704791, non-ribbed style. passenger side is a 3704792 with a tombstone heat riser(#3713335 on counterweight). gaskets are used on both sides of heat riser.