need advice white scum

You need a PCV system on it. It can prevent the rings from seating properly. Did you have it dyno'd? Was the carb setup close when you first ran it?
The white comes from condensation in the oil, so I'd say you also need to drive the car and let the engine get to operating temp too. Pull that plug, get a PCV in it, and drive the car (not idle... drive it)