Been looking at my SCFS52 again - did some research on crankcase suction through the vent nipple using a tube from the nipple to a jar of white spirit. Discovered fluid spraying out of the side of the engine. The blind side of the camshaft tunnel is cracked. Too long since I bought it to complain, so have sourced a replacement ASP crankcase from JustEngines (ordered Sunday, arr Tues first post). Will re-build and get to know the engine with an aircraft prop. Interestingly the new crankcase came with the bearing in the blind side of the camshaft housing already installed. I wonder how many get bust when people try to put them in themselves! The old one dropped out after heating the case with a hot air paint stripper, so it can't be that difficult. At least I now have a spare crankcase to file fins off to see where w/c pipes might go. I'm wondering about fitting a water-cooled gasket to the rocker box cover, though to go by the old OS engine cooling the backplate and the cylinder is enough. I did say this was along term project!