Author Topic: Bearing shells orientation  (Read 815 times)

Offline Greg65

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Bearing shells orientation
« on: April 23, 2019, 08:09:47 AM »
I spent a rare hour tidying up the workshop the other day and came across a pot of all the scrap bits I replaced which reminded me of a question I had during assembly. On the 400 manual it specifies the orientation of the shell bearings and requires the locating cutout to be facing forward. So why is this required and what is the significance should some one disregard the advice. Before anyone asks, no I haven’t, I just can’t see an obvious reason for the requirement and I’m curious.

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Greg
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Honda CB400 1976
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Re: Bearing shells orientation
« Reply #1 on: April 23, 2019, 12:52:37 PM »
It's more likely reference to conrod bearing shells, as Oddjob points out, the main bearings have to align with crankcase indents for that part which orientates them for you.

Although that hasn't in the past stopped people from torqueing the cases together with those gearbox location pins out of alignment with the machined holes  ;D

The 750 manual states "bearing pawls to front of engine" in section for assembly of conrod.  I'd presume that during the cylinder power stroke the main thrust faces are the ones that have no interrupted bearing surface as presented to the crank during that phase, and so more resilient under load and keeping the oil film more complete at the maximum load site.

 

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