main/big end bearing size differences

[Dolomite_]

What are the size differences for the bearing, i.e between brown and green?

Or could someone point me in the direction of some documentation?

[Bryanj]

Minescule is the answer, the Honda manual gives max and min sizes for pin, rod housing, case housing but not for shell thickness

[McCabe-Thiele (Ted)]

I'm pretty sure members here have said if the particular colour shell is not available then going one size larger just needs the gentle running in.

That might account for the patchy availability of black shells in general.

[Dolomite_]

One of my mains is giving an odd reading, its 0.38mm when the rest are 0.025mm.

Can I assume the clearance is fine if its within the wear limit of 0.02 or 0.05mm?

How close it too close?

[McCabe-Thiele (Ted)]

One of my mains is giving an odd reading, its 0.38mm when the rest are 0.025mm.

Can I assume the clearance is fine if its within the wear limit of 0.02 or 0.05mm?

How close it too close?

Which main bearing is the odd one out and what is the corresponding casing code?
What is the actual journal diameter of the crank on that journal?

You have a massive difference in the two measurements you have quoted.
That first figure 0.38 mm is more than ten times greater than the second figure of 0.025 mm is it a typo should it be O.038mm?

What is the Plastigauge reading in microns compared to the other four?
If the clearance is within the manual readings of 20-50 u then it's okay.

What colour shell have you placed in that journal, if the clearance is way too small you need the next smaller colour or visa versa if it's too big - if that makes sense.

Your casing codes shown in previous  post was B A A A A
B being number one main journal.

Might be worth checking the journal again after rotating the crank 90 degrees to rule out a bent crank.

[Bryanj]

0.38 is so big its impossible UNLESS the journal pin is badly worn, in which case it would be oval as well so that journal needs very carefull measuring with quality micrometer

[Dolomite_]

Miss type, its 0.038mm

I guess its just because I got a reading 1 thousandth less than the other ones. I'll remeasure and do another plastiguage check.

I guess as long as its between 0.02 and 0.05mm it should be fine.

[McCabe-Thiele (Ted)]

Out of interest which journal number is it?

[Dolomite_]

Out of interest which journal number is it?

From the generator/stator end its number 2.

[McCabe-Thiele (Ted)]

I'm assuming you have put a Brown shell in number 2 main journal - if you have ruled out crank ovality might be worth tracking down a pair of black shells to reduce the clearance so it's more on line with the others.

I've sold all my spare black shells but a member here might have a pair they are willing to part with - worth a try.

[Matt_Harrington]

If measurements are all within service limits, then I wouldn't worry!

[Dolomite_]

I'm assuming you have put a Brown shell in number 2 main journal - if you have ruled out crank ovality might be worth tracking down a pair of black shells to reduce the clearance so it's more on line with the others.

I've sold all my spare black shells but a member here might have a pair they are willing to part with - worth a try.

Got around to measuring with my brown shells, it goes down to around 0.025mm, so I'll just replace that green with a brown. That means it will be BBGBB, but could I get away with BBBBB? I'll measure again trying a brown in the middle main.

[McCabe-Thiele (Ted)]

BBGBB looks as though they will all be a similar clearance - I would probably worry unnecessarily if I left them at BBBBB.

Your choice at the end of the day, only you will know one main journal has more clearance.