New big ends: end float

["Slack Alice" Simon]

Good evening, assembled gurus,

What, if any, is the recommended end float for big ends on a re-ground crank with re-metalled rods?

3 of the rods move back and forth a little, the fourth not at all, though not tight, since the engine turns by hand.

I have yet to remove the block and see if they have been "barrelled" - or whatever it is called.

Thanks

Simon

[Zetomagneto]

Woodrow says up to 1/16"'. That would be excessive for a pressure fed crank, but probably ok for a splash feed

[Alan]

12 to 15 thou.

["Slack Alice" Simon]

12 to 15 thou.

Thanks

Three are 10 thou ish and one is near zero - I will get scraping!

[Zetomagneto]

12 to 15 thou.

Thanks

Three are 10 thou ish and one is near zero - I will get scraping!

A file would be easier than scraping for side clearance, or a piece of abrasive paper placed on a surface plate with cap assembled to the rod.Measure the width with caliper or micrometer before you start, then keep checking until you have reduced sufficiently to give the target clearance.

[Ruairidh Dunford]

Be very careful which abrasive paper you choose, if you go that route.

I have noticed carborundum, for example, will attach (embed) itself (in)to soft metal.

[Chris KC]

Be very careful which abrasive paper you choose, if you go that route.  

I have noticed carborundum, for example, will attach (embed) itself (in)to soft metal.

Spot on - plain bearing materials are specified such that hard particles easily embed in the surface, as this is preferable to them sitting proud. Clearly highly desirable that they do neither!