Cam Cover Install Question

my euro 328 ABS 1989 had wavy washers fitted under the dome nuts when i did my cam seals/belt change. right or wrong that what was fitted on mine.
still leak free for the time being

 

The star and split washers provide more positive "grip" and in fact will cause damage to both the nut and the surface when you remove them so they are more appropriate for applications that aren't normally going to be accessed. Cam covers need to come off to check valve clearances and such and they use the dressy acorn nuts that you don't want to have to replace after each service. Nylocs are a more modern approach for applications thast are not high heat but they also are technically single use (although lots of people reuse them)

The thing about the star and split washer though is that in order to protect the engine surface you use a flat washer so the nut is locked to the flat washer which is not locked to the engine surface so they aren't perfect.