I think it was Trev from Newcastle ( TrevinOZ ) does LG2 sleeves shrunk back into the original steel outer which should work even better but is too much fiddleing around for me to attempt .
Thought he may have chimed in but perhaps not as he is a pre-unit twin man so may have skipped this thread.
The only other thig to mention is LG2 comes in two forms,
'Continiously cast solid & extruded tube.
For this application the extrude is by far the better material to use due to finer grain size & beter grain orientation .

LG2 is a universal bearing material.
We used to make at least 1 pour ( approx 6 ton ) a week as SFI .
the only place I would use something different is for valve guides because you want the guide to be harder than the valve stem in which case a phos bronze would be the go, and a leaded phos bronze even better .

And yes Ignoramus is correct about machining,
high speeds with negative / neutral rake
Hand scrapes beautifully if you have some old worn out files that need to be repurposed & the skills to use them.

And that should be WAS a metallurgist, been 40 years since I wore a dust coat .
I find myself needing to whip out the ASM handbooks a bit more often these days.
But yes it is good to be in agreement for a change.

As for the warnings about solid bushes, they should all be fine.
The big problem is most copper based bearing materials look very much the same so it is difficult to tell exactly what materail they are made from visually.
I got some bushes for the M20's box decades ago that were actully cast then machined ( badly ) to ( almost ) size.
A cast bush is highly likely to crack radially and then of course crumble away and I have a feeling that the warnings may have come from that happening.
These things are what you would expect to find unbranded for sale on evil pay or ammo-zone very cheap .
As a rule a good supplier will be able to tell you exctly what alloy the bushes they are selling are made from.
If not go some where else, and by exactly I mean LG 1, or 2 or 3 ( etc ) PB 1, 2 ( same thing ) .
For the USA it should be a 3 or 4 number material code.
If they just say "bronze " then walk away .

Last edited by BSA_WM20; 02/15/21 12:57 pm.

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