Hi Shaun...As regards the paper O ring needing jointing compound on it. The factory stated that due to the very high pressure in the tunnel, jointing compound simply is not strong enough or in essence too fluid to retain the oil, as presumably, it gets pushed out. Using a trapped paper gasket works because it is not a viscous fluid and has an inherent strength when its entire surface is trapped under dry pressure by the crankcase faces. If you coat the gasket with jointing compound and create a sandwich of compound/paper/compound, you are actual back to the situation you had without the paper gasket fitted. In fact, it is twice as likely to leak simply because the compound once again can be driven off the gasket and, in this setup, there are now two sides it can leak out.
PS: Thanks for showing how it is done Poul...It still terrifies me though, as one minute handling/machining error can ruin the cases! I don't think I could find someone to trust to do it unless they were something like an F1 engine builder
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