Finally have the sump off – pulled the big ends and found this. Myself, I don’t think they look that bad, they’re certainly not pitted and as there is no other metallica in the sump / oil pump / or engine case. I am now more concerned that my spun bearing noise/knock is something else (turbo – but the knock?)... Then again what do I know?
All / any comments appreciated
In any case, now they’re out I will replace them. Part numbers on all shells are 46430579 (GL81) with 2475(?) and the date 03/03 on the other end. The crank and two of the big ends are daubed with red paint. EPER tells me my chassis/engine could use one of six sets (part numbers 71728417 thru 22) dependant on original sizes or regrind (I guess), ie.
71728417 SP= 1,527 ~ 1,531
71728418 SP= 1,530 ~ 1,534
71728419 SP= 1,533 ~ 1,537
71728420 SP= 1,590 ~ 1,594
71728421 SP= 1,593 ~ 1,597
71728422 SP= 1,596 ~ 1,600
So which set is original? My thinking leads me to think that the latter group (20-22) would be as the unit of measurement is bigger (perhaps three sizes for tolerance). The first group (17-19) appear smaller – to fit a smaller, ground crank journal (?). Is that how it works?
I’m pretty sure from searching that the red paint indicates a standard size – however, EPER doesn’t tell me (in English) which one of those sets it is. I realise I could just rock up to Alfa and ask – but i’m more interested to know how it all works.
Any thoughts, comments etc appreciated
(I might pull a main cap off and check those too, unless somebody thinks that’s a bad idea.. )