It looks like I may have found what was causing the noise in the B33 engine.
Monday and I made a start on taking the engine out of the B33. I removed the sump plate and looked at the magnetic drain plug.
Quite a few particles were stuck to it.
Tuesday and it looks one of the nine timing side rollers has failed - on the plus side, Drift Innovations are going to replace my HD Ghost camera.
The camera works fine, it's just that it drains the battery even when the camera is turned off.
Didn't really do much during the week. Loaded the trailer up on Saturday and left it in the back garden ready for an early start tomorrow.
Sunday - by tea time I was the best part of 300 miles away in Belgium . . . . but that's another story.