Back in the early 1970s I had one of the first design O.S./Graupner Wankel engines.
It failed after about 20 minutes total run time.
The rotor tip seals looked OK. However, its loss of compression was due to the poor seal between the sides of the rotor and the front and rear cases. There is a lot more contact and wear there than on the rotor tips with no seal of any sort.
Even then, it was a monumental problem to get any parts. Additionally, to replace the rotor and front and rear plates would have cost more than replacing the engine. Consequently, given its extremely short life and extremely high replacement purchase cost, the engine was just tossed into the junk parts bin.
Subsequently it was sold off as a instructional Wankel demo to show how it worked internally.
Overall it was an interesting experience from start to finish but in no need of a repeat.
By the way, if you do get seals, do check closely. On mine, there were two springs on each tip seal. the tip seal is a separate piece, pushed against the rotor housing by those springs.
Last edited by do335a; 11-13-2017 at 09:18 AM.