When I stripped the engine of my early C25 (Engine and frame No C25-317) there were no shims fitted anywhere on the crankshaft. The manual states that shims to adjust end float should be fitted between the timing side main bearing and crankshaft web.
The crankshaft web is stamped with "52" and the crankcase is stamped "56" below the front engine mounting lug. When I rebuilt my A50, the crankshaft and crankcase were stamped in a similar manner and the manual states that these stamped numbers show the crankshaft end float when the engine was initially assembled by subtracting the number on the crankshaft from the number on the crankcase. I can see no mention of this being the same in the C25 manual or the excellent Rupert Ratio book. Does anyone know if this does apply to the C25? If it is, then this would explain why there were no shims fitted as 0.004" is within the tolerance for end float.
A second question. I want to use the plate glass and grinding paste method to attend to the timing side crankcase sealing surface where it mates with the inner timing cover. Can the two solid steel dowels be removed by heating the crankcase in the same way as the hollow dowels can be removed?
Thanks for reading this.
As said, there is no mention of end float numbers stamped on the crankcase or crankshaft in the workshop manual. However, it is highly unlikely that BSA would have been able to machine the engine components to give the correct end float of 3-5 thou without the use of a single shim! If you are rebuilding the engine, it's always good practice to measure the crankshaft end float as it currently is because it will almost certainly have increased over the very long time that has elapsed since the bike was first built.
In terms of the dowels, they will have been pressed into the covers and should be easy to remove by applying a bit of heat.
Thanks for the reply Spaceman. I am planning to measure the end float anyway, I was just surprised to see no shim in place when I stripped the engine. The big end journal has been reground, the flywheels modified to take the later conrod and new main bearings will be fitted. I'll heat the crankcase and have a go at removing the dowels, I wish I had done that when removing the bearings!