Author Topic: Big end clearance and indium coating  (Read 6871 times)

Online KiwiGF

  • Last had an A10 in 1976, in 2011 it was time for my 2nd one. It was the project from HELL (but I learned a lot....)
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Re: Big end clearance and indium coating
« Reply #15 on: 09.12. 2011 22:53 »
John I have corrected my earlier post the price I paid for rods was 250gbp plus freight zero VAT
New Zealand

1956 A10 Golden Flash (1st finished project)

1949 B31 rigid “400cc hot rod” (2nd finished project, + favourite bike)

GL1800 Goldwing, well, the wife likes it

KTM 950 ADV, cos it’s 100% nuts

1952 Armstrong Siddeley Whitley for rainy days (with wife)

Offline MG

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Re: Big end clearance and indium coating
« Reply #16 on: 10.12. 2011 08:29 »
FYI, a comparison of different bearing technologies wrt to load capability, from German literature, bearing types from left to right are:
white metal - two-metal - three-metal Pb-based - three-metal Sn-based - groove-type (Miba system) - Synthec - sputtered - lead-free sputtered w/ running-in layer

Thought you might find this interesting.

Cheers, Markus
1955 A7 Shooting Star
1956 A10 Golden Flash
1961 Matchless G12 CSR

www.histo-tech.at - Restoration, Repairs, Racing

Austria

Offline bonny

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Re: Big end clearance and indium coating
« Reply #17 on: 16.12. 2011 18:16 »
Thanks Very much guys...like most times a good set of experiences and I've decided to keep the Mca brand shells and ask for 001 clearance ...fingers crossed that works out and if doesn't I'll report back here.....

The rods I'm using are billet lightning rods from from thunder engineering uk cost 175gbp correction 250gbp not 175gbp! (senior moment) plus freight which I thought a good price they look identical to MAP / SRM rods

The thunder engineering rods are reputed to be very good and are recommended by people like dave nourish of nourish race engines for his engines , i gave up on map as anytime i contacted them for the rods i wanted , they told me to get back to them in a few weeks , this went on endlessly.

Online KiwiGF

  • Last had an A10 in 1976, in 2011 it was time for my 2nd one. It was the project from HELL (but I learned a lot....)
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Re: Big end clearance and indium coating
« Reply #18 on: 16.12. 2011 21:10 »
I might be spicing things up a bit here.....but as regards softer shells not wearing the crank journals as much I've always thought that in general (and only when lube is present) it's the softer part of a plain bearing that wears the least as harder metal particles - including particals from the other, harder part of the bearing- embed themselves in the surface of the softer part, effectively reducing wear of the softer part to a fraction of that which occurs on the harder part.

If lube is NOT present in enough quantity then the softer part will suffer high wear.

I get my reground crank back today and will be able to see if the Mca shells have glacier markings, the eng company said they were definitely not white metal though.
New Zealand

1956 A10 Golden Flash (1st finished project)

1949 B31 rigid “400cc hot rod” (2nd finished project, + favourite bike)

GL1800 Goldwing, well, the wife likes it

KTM 950 ADV, cos it’s 100% nuts

1952 Armstrong Siddeley Whitley for rainy days (with wife)

Offline MG

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Re: Big end clearance and indium coating
« Reply #19 on: 16.12. 2011 21:20 »
Embedded particles can have a lapping effect on the crank journal, mainly an issue when running without an oil filter I would think.
1955 A7 Shooting Star
1956 A10 Golden Flash
1961 Matchless G12 CSR

www.histo-tech.at - Restoration, Repairs, Racing

Austria

Offline kommando

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Re: Big end clearance and indium coating
« Reply #20 on: 20.12. 2011 17:13 »
Initially the soft layer is thick enough to absorb the hard particles and deep enough not to wear the journals, once the soft layer wears then the particles are re-exposed and then they wear the journal. Hence for a roadbike the harder surfaced Al/Sn bearings with a good filter are better than the VP2 bearings as the Al/Sn does not have the soft layer to wear away so it maintains size for longer and the filter takes care of the particles. VP2 in a race bike that is rebuilt yearly with new shells never has these problems and can even but run without a filter as the soft layer is renewed annually.
No BSA twins just unit singles
Scotland