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New big ends: end float
#1
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
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#2
Woodrow says up to 1/16"'. That would be excessive for a pressure fed crank, but probably ok for a splash feed
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#3
12 to 15 thou.
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#4
(09-11-2017, 11:32 PM)Alan Wrote: 12 to 15 thou.

Thanks

Three are 10 thou ish and one is near zero - I will get scraping!
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#5
(10-11-2017, 10:50 AM)Slack Alice Wrote:
(09-11-2017, 11:32 PM)Alan Wrote: 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.
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#6
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.
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#7
(10-11-2017, 12:56 PM)Ruairidh Dunford Wrote: 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!
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