AO Silver Member
Join Date: Nov 2003
Location: United Kingdom
County: Perth and Kinross
Re: Not Again!!!!
I don't know the specs, but in this case just looking at it will be sufficient. If the journals show signs of metal to metal, it will need reground and undersize shells fitted. If it looks ok, with nicely polished journals, a quick polish and standard shells would be ok.
If the damage is so deep, it may be that you cannot have it reground because it would be too small for the undersize shells. In that case a new crankshaft is necessary. A competent engineer or even a good mechanic should likely know almost immediately by little more than visual inspection.
A decent engineer would also advise the crankshaft gallery end plugs would need renewal in order to clean inside the cranshaft oil-ways. That should only be necessary if main bearing and not just big end damage had occurred, though.
An engineering machine shop will have all the specs required.
One point of soft metal bearings and a hardened surface on the crankshaft is that the bearing shells are sacrificial in event of metal to metal damage meaning that crankshaft damage is minimal.
When I rebuilt my 156 engine, I used higher quality AE components and Payen gaskets as my machinist told me the Alfa engine internals are crap due to Fiat cost cutting. That's why I avoided genuine parts. Don't take that as gospel across the board though. Many non-engine OEM parts are quite good.
[SIGPIC][/SIGPIC]Drive sideways- life's too short not to
Slip-sliding my way through winter. On four wheels and two.
Last edited by ally; 08-08-08 at 10:33.