Spline wear like that is common on Squares. I think I will be using the rear crank from my other engine unless I can get the splines welded up and recut. It looks as if the crankcases were NOS when fitted to the bike but the cranks had seen plenty of use, although only newly reground to -0.010. The timing side bushes had melted the whitemetal as I thought but the bushes came off easily enough once warmed enough to melt the whitemetal again. This revealed newly reground timing side journals.
I took the sludge trap screws out despite evidence from mutiple centre punch marks that they had been out fairly recently. Each of the four traps had some debris in it. Whilst some was undoubtedly running in debris from the 100 miles or so done before the bike left the factory, I think some was from imperfect cleaning of the cranks. There are bits of carbon visible on the cranks which will wash off with detergent oils in time, I believe. Before the cranks go back into use I will remove the balance weights and flywheels so I can get the whole crank spotlessly clean.
Then I got out my rear crank from my spare engine (spare at present but destined for my swinging arm Square Four once I finish the Healey). This crank has been ground to -0.020 and might need a further grind before use, although the splines are very good. But the sludge trap screws did not appear ever to have been removed. So I took them out and sure enough, the traps were well blocked. Why on earth someone would regrind the cranks without looking at the sludge traps I cannot imagine but this could have been done twice on this crank. The cranks on my 1936 4G had also been recently reground but had totally blocked sludge traps. Perhaps crank grinders are better machinists than they are mechanics and perhaps the mechanics left everything to the crank grinders.
36 4G, 37 VH, 53 ex ISDT KHA (project), 54 KH(A), 54 4G Mk IV (project), Healey 1000/4 (project)
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser.