Hi All Im sure I used to know the answer to these questions but Im getting old and did have a big bump to my head a couple of years back
Did all side plates have the 'spiral' pattern on them or did some have a solid coating all over?
Does anyone know what the material is in the 'spiral' grooves and has anyone ever had one recoated?
Ive just stripped 3 engines plus I have 2 spare side plates and a housing and not one side plate is useable and only one rotor housing! So it would seem this could be a problem if we want to keep our bikes running for the future. All the side plates have the material 'flaking' out of the 'spiral' grooves, One rotor housing has a small nick out of the face but may be useable at a pinch, 2 rotor housings have cracks across the spark plug hole, leaving the 1 good one
The coating is molybdenum disulphide as used in the norton rotary engines.
Cracks at the spark plug holes are not ideal but you can reuse them. If they are cracked all the way to the edge I'd probably not though.
The actual surface of the rotor housing can be reground very carefully with a brand new emery stone and lots of water/oil. Use the fine side only. This is to correct bad chatter marks and grooves around the edges.
Perth, Western Oz 1975 RE5M x 2 02 Beemer R1100S mature conveyance Some dirt bikes for fun! Wish list: Just about everything in Jay Leno's garage
The first engine I stripped had the fully coated side plates and the other 3 have the 'spirals'. Interestingly the bike this engine came from is only 1 frame number away from mine yet mine has the spirals. All the engines still had the factory seal in place
I am having some Norton Classic side plates coated in England right now. They mill a groove about .020" deep in a pattern that follows the rotor path (trochoid path), then fill it with molly and grind it flat and smooth. At some point, this could be done with RE5 plates, but would take some commitment.