Have you ever taken your engine apart and wondered how the bronze half-round main bearing or big end shells are made? They’re the ones that have a thin layer of white metal attached. Well, here’s your answer!
I’m just starting a full white-metal project so thought I’d put it all up on here for you all to see. This will go right through from a bar of round phosphor bronze and some ingots of white metal right through to finished machined bearnings (and a rebuilt engine).
We start with some hollow round bar (which is not the same as a tube) phosphor bronze PB1. This is 3.2″ outside diameter and, err, expensive! These bits are 11″ long as it makes it more manageable to turn on the lathe, but that’s a later step.
Firstly, we have to split the bar along the centre line. This cut will be the finished interface between the two finished halves.
The blade is only 0.047″ (about 1.25mm) thick so it’s a bit of a tricky job and coolant gets flung everywhere, but it’s worth doing properly. On the far side that’s already cut most of the way through I’ve put in some shims to prevent the bar collapsing (which is why it’s tricky to cut with the slitting saw!).
I’ll put up the next step tomorrow once I’ve machined it!