Crankcase rear main seal modification

[Lotus211]

I apologize if this question has been asked before.

Are there any recommendations for modifying the rear main seal to prevent future maintenance such as a modern rubber seal?

[114015]

Hello Lotus,

To make a long story short...,
basically there is no proper or feasible way to replace the Borgmann Ring by anything else.
There were ideas though,
but basically the rear flange of the crank is to large (in diameter) to fit a proper rotary shaft seal over the flange towards the groove in the crankcase.

Achim

[Shvegel]

I started down this path a few years ago and experimented with a number of seal styles.  I machined a mockup of the crank pin in aluminum and started trying different arrangements. The most promising was the Ford 460 style 2 piece seal which I re-arced and shortened.  I also machined an adaptor to hold the seal.  After all that I ended up reinstalling the rope seal.  It was a question of the known versus the unknown.  I know the rope seal will seal for awhile and maybe the ford seal will fix the problem but if it leaks I have to pull the whole thing back apart again.