At 02:41 PM 9/16/2000 EDT, Eganb@aol.com wrote:
>...
>In the WWWedge archives I read an email from someone who claims that you
should not put oil on the back side of the bearings when assemblying them
-- something about needing metal-to-metal contact for correct heat
dissipation. ....
>....
Correct advice, but wrong reason. There is only about 0.001 inch of
clearance in the bearing journals for oil flow. Anything trapped behind
the bearing shell will reduce the clearance in the journal needed for oil
flow. A human hair behind the shell will reduce the oil flow clearance to
zero, possibly causing the bearing to sieze. If you oil both sides of the
bearing shell when assembling, the oil film will even out with about 0.0005
inch on each side of the shell, which is bad for oil flow when you first
start the engine with cold oil. Once it survives the first few minutes of
running time the bearing shell will be forced back against the saddle to
displace the oil behind the shell and give it intimate metal to metal
contact on the back. It's the first few minutes of running with that
reduced bearing clearance that's critical. Do not oil the back of the
bearing shell.
Brney Gaylord
1958 MGA with an attitude
http://www.ntsource.com/~barneymg
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