SOHC.co.uk Forums > CB350/400
400 four main bearings - will need replacement STD bearings.
Bryanj:
They NEVER mix colours on one pin but different colours on different pins is common.
Non of the numbers on the shells mean anything apart from production code, last thing done in production is measure thickness to 0.001mm and colour code them
McCabe-Thiele (Ted):
--- Quote from: Bryanj on March 21, 2021, 04:34:35 PM ---They NEVER mix colours on one pin but different colours on different pins is common.
Non of the numbers on the shells mean anything apart from production code, last thing done in production is measure thickness to 0.001mm and colour code them
--- End quote ---
I'm learning here I have never encountered a car with such complications as different coded journals on the same crank - wonder why STD didn't mean just that with oversize being +0.1 or whatever.
K2-K6:
"I'm learning here I have never encountered a car with such complications as different coded journals on the same crank - wonder why STD didn't mean just that with oversize being +0.1 or whatever."
It is, in essence, a view of the lengths they went to in production tolerancing. Ordinarily in most process as it advances the tolerances are accumilative (unless by happy accident one error cancels another) with the accepted machine accuracy and repeatability available producing the components being recognized, the range of 5 different shell dimensions is planned to compensate for that process capability. It effectively pulls all of that production line tolerance back to as close to zero that they could get it.
In terms of "old money" a BMC A series built with en40b crank fully balanced, ground, nitrided, micro polished to perfection, with rods balanced end to end and rod to rod, etc etc, effectively the best hand finished blue printing only gets close to what these engines came off the production line as absolute standard. With near 100bhp/litre and usually ten thousand rpm ceiling to go with it, that really shows just how good this design and production was, that's in mid to late sixties and early seventies, there's nothing that came close to them.
Bryanj:
In production Honda used air gauges to measure pins and housing which were accurate to parts of 0.001mm and as such could selectively fit parts to get the EXACT design clearance.
When did you ever hear of an "old" car doing 120 000 miles and on stripdown find everything in tolerance and yes i have seen that, chains were shot but all the rest was good enough to refit
McCabe-Thiele (Ted):
--- Quote from: Oddjob on March 21, 2021, 06:12:57 PM ---What journal was the green shell on Ted?
Must be either 2 or 4.
--- End quote ---
You are right Oddjob the Green Shell was on number 2!
As D6I-A was the bearings on 2 & 4 I guess they are both the same.
I have just removed the Conrods a C is marked on the front edge two of them have number 2 & 3 on the other side but they were not in the respective cylinder bore so I am thinking this number in black print is meaningless. They were all fitted the same way round as regards the side casing number on the side "S59" on all four.
Tommorow I will lift out the crank & check for markings on the shells being carefull they do not lift out with the crank. I will then check each bearing for any colour markings and double check the shell codes.
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