1 5/16 shell bearings

[tomcotez]

It would seem that the only 1 5/16 shell bearings available are Austin ones from 3 bearing cars. I am curious as to whether it has been confirmed that there is no alternative (- i.e. compatible bearing from another engine) or that they are such a niche product that no-one has ever looked into it?

The shells available aren't ideal as they are narrower than the crank journals.

What is the margin to modify bearings - can the locating tabs be re-cut or is the risk of distortion too great?

[Zetomagneto]

Reliant Kitten shells are 1.5/16”.

[Chris KC]

Tom,

The only big end shells you are likely to encounter as replacements are from Reliant engines; our cherished suppliers hold stocks of these.

I can assure you I searched catalogues from at least 4 major bearing shell suppliers in the last 12 months and there is nothing else available off the shelf at this crankpin diameter.

The bearing area of the Reliant shells is generous by modern standards and more than sufficient for the loads concerned. The bearing area of white metal on earlier cars reflects the softness of the material and the vagaries of hand scraping. There is absolutely no need to replicate this load area with modern shells. Keep in mind also that the bearing shells have to clear the fillet radii on the ends of the crankpins.

If you should find it necessary to remove locating tabs on bearing shells this can be done by careful filing. Rest the shell on a wooden or nylon dowel of suitable diameter by way of support, and take great care not to embed filings in the soft bearing metal. Make sure the result is flush with the rest of the steel backing or if necessary slightly low so it does not hold the shell off the housing surface. The tabs only serve to locate the shells in the correct position; once the big end bolts / nuts are torqued up it is the interference fit of the shells in the rod ('nip') which stops them from rotating, not the tabs.

[tomcotez]

Thanks Chris, that answers my question!