400/4 main bearing shells

[davidcumbria]

I suggest If in doubt go for the thicker of the two bearing related to each case code. Eg for C go for green not yellow. There is only 8 micron difference between the shells while the spec tolerance is 24 micron. Very unlikely to breach the lower tolerance and run in carefully should be no problem. I’m not sure about Plastigauge. If the crank is ovalled it all depends where you lay the strip. Would be interesting to know what the actual difference in oil pressure is between the same engine running different shell sizes. I suspect not much but no one knows!

[McCabe-Thiele (Ted)]

I suggest If in doubt go for the thicker of the two bearing related to each case code. Eg for C go for green not yellow. There is only 8 micron difference between the shells while the spec tolerance is 24 micron. Very unlikely to breach the lower tolerance and run in carefully should be no problem. I’m not sure about Plastigauge. If the crank is ovalled it all depends where you lay the strip. Would be interesting to know what the actual difference in oil pressure is between the same engine running different shell sizes. I suspect not much but no one knows!

.Dave I did not think Yellows were listed for a 400 mains journal I thought the tables show Brown or Black for  journal "C" mains ?

Yellows were they not for journals marked A only?

[Matt_Harrington]

OK, Quickly nipped down to inspect my crank cases and the stamps on the lower case are: 'BBBBB'
So now I have a starting point! I'll recheck the journal sizes later and then I can deliberate as to what I fit.
Based on the above, I assume the standard shell would have been green? (Ted, yellow is listed but for size A 1)

[McCabe-Thiele (Ted)]

OK, Quickly nipped down to inspect my crank cases and the stamps on the lower case are: 'BBBBB'
So now I have a starting point! I'll recheck the journal sizes later and then I can deliberate as to what I fit.
Based on the above, I assume the standard shell would have been green? (Ted, yellow is listed but for size A 1)

Correct so as was mentioned by Dave you could fit standard Greens if crank dimensions are still within tolerances or  Browns & run her in carefully - good that you do not have any C's in the code array as shells are generally easier to find for A & B's. If you had a C and the journal was worn Black is hard to find but not impossible.

[Matt_Harrington]

DS has the black ones in stock - at least at the moment!

I need to get everything cleaned and ready for the crank cases and will then proceed. 

Do you just bolt up the front half of the crank cases or all of the bolts for the rear as well when testing the fit of the shells?

[Bryanj]

All the big bolts

[davidcumbria]

.Dave I did not think Yellows were listed for a 400 mains journal I thought the tables show Brown or Black for  journal "C" mains ?

Yellows were they not for journals marked A only?
[/quote]
Sorry yes I got my Aand C mixed up. As Ted said for B ‘s go for brown not green if in any doubt. 4 B s is a lucky result for shell availability.

Also when bolting up don’t forget the locating dowels if you’ve removed them.

[Matt_Harrington]

It's gonig to be a week or so before the cases come back.
It gives me time to sort the other items to replace.....

Thanks for the input so far.

[GC400]

Hi Mark, I have just been through this:

The letters on the case and the numbers on the crank match to a table. I did this method and then measured the clearance with plastiguage and torqued the cases together. When measuring they were all in the centre of the tolerances. For me the chart, letters and numbers worked out to be great.

Only bad thing was I did need yellow and I could only find in Greece.