Exhaust manifold sealing surfaces 220Sb

[joshhol]

Good evening,

I've got multiple things going on with my fin and multiple posts.

At issue here is the state of the exhaust manifold to cylinder head sealing surface.
Long story short- I ordered used exhaust manifolds from an outfit in Germany but only 1 arrived in the box. Box badly damaged, manifold appears to have fallen out. While working with the shippers and vendor to try and resolve the situation, I'm faced with using my existing manifold on the front half of the engine.

Please see pics. The sealing surfaces are rough and fairly pitted. An obvious solution seems to be find a reputable machine shop and smooth out that mounting surface. Were things only that easy. As you can see in the pics, the Fintail manifold assy is a 3 piece deal with front/rear halves of the exhaust mnfld and the central intake mnfld.

If some metal is taken off the front manifold to resurface, would this create some odd angles/gaps when the assembly is bolted together?

The one used manifold that arrived is in decent shape. Not totally smooth but not pitted at all. Fair enough to just use a sealant on the whole thing and hope for the best?

Something to consider is that a valve job may be in the intermediate future (5yrs) disassemble everything again someday.

[Mike D]

I'd cut a sheet of copper and make a thicker gasket until you resolve the shipping dispute.

Pop by your local speed shop, I bet they have sheets of material you can use to create gaskets.

[97 SL320]

Does this system use a exhaust manifold gasket? If so the pitting is less of an issue.

If you can find an older automotive machine shop with a belt sander type cylinder head refinishing machine they can resurface it. Otherwise you will need to build a holding fixture so they can put it in a milling machine / cylinder hear resurfacer.

[gmog220d]

It's a single gasket for both intake and exhaust manifolds, yes? Just like the OM616 and OM615 engines I've worked on.

Shouldn't all the manifolds, both exhaust and the intake, be surfaced together (or separately but to the same spec), since they all share the same studs/nuts holding them to the head? Seems like maintaining the same thickness from where the washers/nuts contact the manifolds to the surfaces that mate with the head would be important across all of them.

[Frank Reiner]

Originally Posted by joshhol

Good evening,

I've got multiple things going on with my fin and multiple posts.

At issue here is the state of the exhaust manifold to cylinder head sealing surface.
Long story short- I ordered used exhaust manifolds from an outfit in Germany but only 1 arrived in the box. Box badly damaged, manifold appears to have fallen out. While working with the shippers and vendor to try and resolve the situation, I'm faced with using my existing manifold on the front half of the engine.

Please see pics. The sealing surfaces are rough and fairly pitted. An obvious solution seems to be find a reputable machine shop and smooth out that mounting surface. Were things only that easy. As you can see in the pics, the Fintail manifold assy is a 3 piece deal with front/rear halves of the exhaust mnfld and the central intake mnfld.

If some metal is taken off the front manifold to resurface, would this create some odd angles/gaps when the assembly is bolted together?

The one used manifold that arrived is in decent shape. Not totally smooth but not pitted at all. Fair enough to just use a sealant on the whole thing and hope for the best?

Something to consider is that a valve job may be in the intermediate future (5yrs) disassemble everything again someday.

Scenario 1:
Milling the gasket surface of the front ex manifold.
If that is done, the stud holes in the front portion of the intake manifold would be slotted to allow the ex manifold to move inward.

Scenario 2:
Filling the pits in the ex manifold.
The pitted surfaces can be thoroughly sand blasted, and brazed to fill the pits. Those surfaces can then be either milled to the original level, or if one is careful (and skillful) the surfaces can be restored with a belt sander, or a large disc sander.

[joshhol]

Yes, a single gasket is used for all three interlocking parts. gmog, I'd say you are right but I don't want to take any material off of the other two manifolds if I can help it. The washer/nut contact area is split between adjacent manifolds so evenness across the 3 is pretty important I'm sure.
Frank, there seems to be a promising shop south of St. Louis, Full Service Automotive Machine Shop In House Springs, Missouri. I'll see if they can do brazing and sanding.

Though 97 SL320, maybe I'm overly concerned about it. A little sealant and it may be good enough. I hope the missing manifold is recovered but I know I'm kidding myself. It has to be somewhere though, it didn't vanish into thin air. The thought of some worker just tossing it in a dumpster is very depressing though as there is only a finite supply of good fin parts in the world.

Thanks All.

[joshhol]

Washer/nut space

[gmog220d]

Originally Posted by joshhol

Washer/nut space

It occurs to me, and this may be what Mr. Reiner described in his "Scenario 1", that one could remove material from the washer/nut surface of a manifold to decrease the distance between that surface and that of the head mating surface in order to match one manifold up to another that had been re-surfaced on the head mating side. (whew!)

As for using sealer or shim material, personally I'd avoid that and would prefer having the manifolds matched up for fit between the washers/nuts and head mating surfaces. The goal would be to achieve equal clamping force between all the manifolds without the use of additional materials.

[97 SL320]

Or just have the entire intake / exhaust manifold system milled down to the same level.

[gmog220d]

Originally Posted by 97 SL320

Or just have the entire intake / exhaust manifold system milled down to the same level.

+1. That would be best, and probably easier for the shop to accomplish. Only has to be done once.

[joshhol]

Going to call the shop soon and see what they say. Still want to avoid removing material as I'll be on the lookout for a better manifold however the snafu with the missing one turns out. I like the idea of brazing and then leveling. Or, I'm just goin to stick it on there as is.