Mike,
The process I follow is to press out the original inner bearing material, thoroughly clean the steel shell, polish the inside, then de-oil with a prep solution.
I then tin the shell with a solder prep solution, then also apply a CIG tinning flux.
I have formed a mold which the shell is set to.
The melting point of the metal is 420 degrees C.
After pouring, it is allowed to cool which takes around 20 minutes.
The machinability of the material is excellent.
I use a tin based alloy which conforms to British Spec DTD214. The maker claims that it is the highest grade standard Tin Base Alloy manufactured anywhere.
It has been designed for fatigue resistance and is particularly suited for diesel engines, and all other types of internal combustion engines.
They list the applications as:
Diesel, Aero, Marine, Oil Steamship,, Gas Engines, Automotive bearings and air compressors.
The material is 'OTL' C.I.E
"A tin Base Alloy containing Cadmium, and harder than other alloys which conform to Spec DTD214. Specially designed for users preferring an alloy containing Cadmium.
Application: Compression Ignition Engines (Diesel). Alternative to 'OTL' AERO A where white metal bearings are specified"
I noticed that one of my old bearings already used white metal, whereas another three used the bronze - lead - whatever else insert. I don't know why they went for the bronze based bearing; was it cost?
Thirty years ago I used to pour and machine large (12" bore" split bearings for crushers), and thought why not do it on a mini scale for the BSA bearings?
Previously to this, I have been machining my own one-piece bearings out of phosphor bronze.