These are some pictures* of a 1982 Weslake prototype with a plain bearing. In this engine you find a one piece crankshaft with the bolted on flywheels.
To keep the new bearing moving a positive oil feed was required, and therefore a new gear-oil pump has been housed on the timing side. Driven by a worm on the journal it delivers oil at very high pressure to the crank centre.
The filter, originally housed in an ugly protrusion, has been incorporated into the pump casing and all in all the thing looks both businesslike and neat.
Flywheels of different weight and balance can be added to the basic centre to change overall characteristics.
Below are both the photographs* of these new components, together with a diagram of how they are assembled into the engine.