c1 rear main seal

[Thomas G.]

My 56 motor was rebuilt using a new rope seal. It leaked a small amount during break in and has not been run since. While I have the pan off now, I was planning to replace the rope seal with the Paragon 56 seal. After removing the rear main cap I discovered the crank is pitted in the seal area. I'm afraid to install the new neoprene seal for fear it will leak more than the rope. I'm thinking that the rope might be better since it has more surface area. HELP!

Has anyone installed a double lip seal designed for later blocks in a 56 by modifying the seal to fit the v-shaped goove?

Thanks for any responses.

Tom

[Joe L.]

Re: c1 rear main seal

My 56 motor was rebuilt using a new rope seal. It leaked a small amount during break in and has not been run since. While I have the pan off now, I was planning to replace the rope seal with the Paragon 56 seal. After removing the rear main cap I discovered the crank is pitted in the seal area. I'm afraid to install the new neoprene seal for fear it will leak more than the rope. I'm thinking that the rope might be better since it has more surface area. HELP!

Has anyone installed a double lip seal designed for later blocks in a 56 by modifying the seal to fit the v-shaped goove?

Thanks for any responses.

Tom

Tom-----


I agree with you. As bad as the rope seals are, I think they would work better than a neoprene lip seal in the case of the damaged crank as you describe. However, a lot depends on just how and where the crank is damaged. If it's damaged across most of the seal surface from front to rear, I think you're better off with the rope seal. However, if the area where the lip of the neoprene seal would contact the seal surface through 360 degrees is ok, then the lip seal should work fine. You only need a very narrow "band" of good surface through 360 degrees for the lip seal to work properly. With a lip seal, though, if the lip contacts any part of the damaged area, the seal will be quickly destroyed and the leak will go from bad to worse.

If the crankshaft's seal surface is damaged so that the neoprene seal won't work, then I think you're going to have to be satisfied with whatever leak you get with the rope seal on the damaged surface.