1991 350SDL Does the 603 engine have a sealing ring under the prechamber flange

[W Black]

Does the 603 engine have a sealing ring under the prechamber flange?
Or is it a surface to surface seal between the head and flange?

Thanks

[benzguy300]

It does have a sealing ring

[Obamalamadingdong]

Originally Posted by W Black

Does the 603 engine have a sealing ring under the prechamber flange?
Or is it a surface to surface seal between the head and flange?

Thanks

If you are referring to a "seal ring" similar to the type used in the OM 617 engine, no they do not.

There is a "Seal Ring" for the OM60x family of engines but it is completely different in design and function that those for the OM 61X engines.

In the event the OM 603 cylinder head is resurfaced within its spec limit there is a chance that the prechambers would then protrude too far into the combustion chamber. The remedy it to use a "Seal Ring" of the proper dimensional thickness possibly combined with the special tool to cut the prechamber seat depth to bring the prechamber's protrusion depth into the combustion chamber into spec. The "Seal Ring" comes in three thicknesses, 0.3 - 0.6 - 1.0 mm. The design difference is the OM60X "Seal Ring" fits down into the prechamber bore in the cylinder head in the position of the "shoulder" of the prechamber, it does not fit under the prechamber's flange.

Unlike the OM61X engines there is no standard size "Seal Ring" for the OM60X engines.

[oldiesel]

Just finished resealing one of the prechambers in my 87, there was no seal under it.After cleaning the surface in the head and and the prechamber very thoroughly i put a little Permatex aviation sealant (rated for 400deg F) under the lip of the prechamber and let it sit overnight to thicken up before installing the prechamber.
I had to make a couple of tools to do the job. 1 with the threaded part from the bike tool to use with a slidehammer to pull the pc.2 made from a 1/2" drive socket to unscrew and retourque the retainer.
So far i have only driven it about 30 mile and it seems to be fixed.

[winmutt]

400f is hardly enough.

[dieseldiehard]

need to do it the right way? dealer sells the spacer shims for about $15.