In the process of building up a new engine and have replaced the balance shaft bearings but puzzled as to why the lubrication groove in the front journal only goes part way round. Has anyone experimented with extending the groove right round or any other mods to help preserve the bearings. The back journal is just plain, no groove. Did the works engines run the same shaft /bearing setup ?
The groove picks up the oil then it smears it around the bearing so thats normal. To preserve the bearings..never let the engine sit for long periods of time, rust can build up on the balance shaft faces and when you start the engine it acts like grinding paste, this is why many restoration project engines fail not long after the car gets back on the road. Regular oil changes help. Run the fan belt as loose as possible..over tightening pulls the balance shaft to one side and promotes early wear (ovaling). I think works engines run the same shaft/bearing..it's there to smooth engine "wobble" and can't really be improved on so look after it. Don't forget your camshaft bearings can also fail and jamb up so when the engine is on the bench check/change them at the same time.
'73 96 (Vernon),'74 95 (Veronica)plus 4 other 95's and 2 96's
Further to what John has just said, I always add a shot of molyslip to my engine oil. This has a plating action on bearing surfaces which will protect them (for a while, anyway!) from the worst effects of oil starvation.
I learned about molyslip back in my karting days. We were usually the only team to get through a season without an engine seizure! This was attributed to our mechanical expert insisting that we ran a moly based oil rather than the Castrol R that everyone else used......!
-- Pete "Duct tape is like the Force: It has a light side and a dark side, and it binds the Universe together!"