Project 1934 VG 500

[Roger Gwynn]

They would not have been polished originally but left as cast, unless specially ordered or if it was for exhibition. Be very careful welding these cases, in fact avoid doing it and use a modern high strength epoxy instead. The material used contained something in the mix, probably zinc and lead, that makes them prone to cracking, especially when welded. You are very lucky to have ones that are in such good condition. If the cases have a tendency to leak oil because of damage I would run the bike without oil and use chain spray to lube the chain and shock absorber. The clutch bearing will run for a long time on the grease used for assembly, bearing in mind that it only spins when the clutch is pulled in.

[AlbertR]

They would not have been polished originally but left as cast, unless specially ordered or if it was for exhibition. Be very careful welding these cases, in fact avoid doing it and use a modern high strength epoxy instead. The material used contained something in the mix, probably zinc and lead, that makes them prone to cracking, especially when welded. You are very lucky to have ones that are in such good condition. If the cases have a tendency to leak oil because of damage I would run the bike without oil and use chain spray to lube the chain and shock absorber. The clutch bearing will run for a long time on the grease used for assembly, bearing in mind that it only spins when the clutch is pulled in.

Hi Roger thanks so much, for that little crack on the thread i planned to use aluminium epoxy resin for sure, i'm not risking with this at all. So far it doesn't look it would leak any oil, I'll save your advice when i look into that this weekend.
The fact is that as i didn't disassemble the bike i have little idea how the bike actually runs, so its all new for me and to be learnt. Its the first classic bike i look at, my experience is on cars, mainly with my Austin a35 from 1957, but mechanics is completely different.
So I need to read through the workshop manual still.

In regards to polishing, the timing cover and some other bits have been polished already so I'll get the case to some extend to match this other parts, without getting it to "perfect mirror looking" polishing. Just to match current parts.