Installing 8 cylinder manifold

[ricosan]

Good morning all,

Today I am reinstalling my 1932 Marmon 8 exhaust/intake manifold. I read that you should use graphite between the gasket and the head so that the manifold can "move" under heating/cooling conditions. Is this true or should I just leave it just the way it is or is there some other product that will do the same thing yet offer help in getting a good seal? All comments welcome.

ricosan

[Guest cben09]

The manifold runs much hotter than the head,,and must expand/creep against the head,,

Don't overtighten the nuts,,use brass nuts if you can,,graphite,,never sieze are O-K,,,

Use steel gaskets not copper if you can,,,there willl be galvanic corrosion in 30 years or less

YES,,I had the occasion to take my work apart after 30-40 years,,the "nice" copper had eaten

the cast iron,,quite a bit,,I chose to do a cold repair,,on a long manifold,,,Smooth-On cement

Worked nicely,,and avoids machining,,,I used a 2''x4 ''alluminum to bolt to,,Flat and avoids machining,,,The red and orange,,silicon sealer,,,Hi temp applications,,works great and stays soft and plyable,,Hope this helps,,,Ben

[Rusty_OToole]

Check first that the manifolds are not warped (with a straightedge). If intake and exhaust are bolted together, it helps to leave the bolts loose, bolt the manifolds to the engine, then tighten the manifold to manifold bolts.

If the manifold is warped it can be machined flat by an auto machine shop.

[JFranklin]

Never seize would be what to use. ditto on not over tightening the nuts and make sure to go center out in gradual steps.

[motoringicons]

Use gland rings, especially for the exhaust manifold. Gland rings will keep the manifold from warping. The best combination is a gland ring and then slip on a crush ring (usually steel or copper with asbestos-like material on the inside). The gland ring keeps the manifold inline, the crush ring is the gasket. This works much better than a standard flat material gasket and is closer to what was originally used. As stated above, use anti-seize on the threads and use a brass nut on the manifold stud. Here is a photo of what a proper manifold gasket/gland ring combination should look like (this is a four cylinder engine set). You can make the gland rings, they should be made from a spring steel material. They should be thick enough to connect from the block port into the manifold port. The crush rings are available from Restoration Supply Company who sells them in a variety of sizes.

By the way, is your Marmon an 8-125? That car in your avatar looks like the 8-125 that passed through my hands not too long ago. Here is a photo of the car I sold.

Edited February 8, 2014 by motoringicons (see edit history)

[ricosan]

Good morning everyone and thanks for all the information. I successfully put the manifold back on the car yesterday and started it. It doesn't run smoothly but it didn't run very smoothly before the manifold re-installation. I only had 4 crush rings in the head when I installed yesterday. I'm checking with restoration supply today. Mine look like the rings with the slot.

ricosan

[trimacar]

Pierce Arrow used an "arched" washer on the straight eight manifolds, thus it could expand also and let the manifold expand without putting as much tension on it.

Your Marmon looks great!

[GLong]

Ricosan, when you say your engine doesn't run smoothly, please describe more, or start a thread in the technical section, where we can go through the diagnosis of your rough running engine..

ANY straight eight should run quite smooth, My tired old '33 pierce, even with unequal compression idles smooth enough to balance a nickel on the cylinder head.

Or, pm me, with your email address and I'll see if i can't help getting your engine sorted.

Greg L