Copper/mineral filling Washer (traditionally called a Copanda washer - has heat resistent crushable material inside) used with SOHC and DOHC Bevel Union Nut on upper and lower castings. Should normally be replaced each time nut is refitted to avoid leaking
Originally, at the time Norton was manufacturing these Cammy engines, these washers were commonly filled with an abestos type filling. However, as abestos is now recognised as a hazardous material - these modern versions are filled with mineral heat resistent material. They 'crush' slightly on tightening the bevel nuts, and provide a good seal.
We have had the tooling made for producing this crushable washer, and do not supply these to any other supplier. Although they look simple - they are manufactured to work as the original's - which includes ensuring they look the same as originals once tightened (i.e. visually they are centralised as per the originals, in line with the bevel nut lip, as they are very visible on the timing side of the engine). It is normal practice to replace them each time the cambox is removed.
They are flat on one side, and slightly curved (crushable) on the other side. I normally fit the flat side on the Bevel Housing casting side, and the curved (crushable) face on the nut side.
Price is each.
Update March 2024: Unfortunately the manufacturing cost of this copper/mineral washer has doubled since last ordered 2 years ago!! (partily the material cost). We have only increased the retail price by a fraction of this amount.