For several years Ruby's engine has been difficult to start, especially on cold days. This is typical of a diesel engine that is suffering from a lack of engine compression. This is usually caused by a failure of the piston rings to grip the cylinder liners sufficiently well, which means that the compressed air escapse down the cylinder and into the crank case.
Ruby has also suffered from heavy breathing i.e. steam and exhaust gases coming out of the crank-case breather pipe. This was caused by moisture getting into the crank case, from two broken injector sleeves and warn piston rings on one, possibly more pistons.
So the engine was re-built using the block and crank case from a donor Leyland O.600 engine (from a Leyland Leopard). The top and bottom of Ruby's own Leyland O.600 engine were in a good condition, so were re-used.
Below are a series of pictures that show the old engine being stripped-down (first 7 images) and the shinny rebuilt engine in place.
She now starts really quickly and no longer breathes like a steam engine. But still sounds absolutely fabulous!