[s-cars] Fw: Crank bearings - AAN

[Aaron Taylor]

Sorry - I know nothing about rebuilding these specific motors but...
With the power on the DOWN stroke wouldn't the reaction at the bearing be on the
LOWER half of the bearing thus requiring the harder material on the lower half or
am I missing something.
Aaron

QSHIPQ at aol.com wrote:

> --
> [ Picked text/plain from multipart/alternative ]
> Colin:
> Just in lurk mode for a while.  WRT you post, the hardened shells go ON THE
> TOP (the suffix 701B - the expensive ones).  You put them on the bottom, the
> motor will last about 10 minutes or so.  Remember, the power is on the down
> stroke....
>
> That said, the 701 non hardened, and the 701B are interchangeable, so yes the
> 701B can be used top and bottom for a stronger motor.  I've done this, can't
> really comment on longevity, as the mileage hasn't acumulated enough on any
> of the motors.
>
> Given the construction of both, I'd not hesitate to use 701B top and bottom
> on a motor rebuild.
>
> HTH
>
> Scott Justusson
> QSHIPQ Performance Tuning
> Chicago
> In a message dated 5/1/02 5:11:33 PM Central Daylight Time,
> ccohen5 at compuserve.com writes:
>
> | The family bible is specific about a top and bottom bearing and I believe
> | from Scott J, that that bottom (yellow/purple) is harder than the top
> | (yellow).
> |
> | So my question is (in the absence of Scott J who may have unsubbed for a
> | while) can you use the harder bearing on top and bottom without increasing
> | wear on the journals.  I have not done this extensive a rebuild in 20
> years,
> | but I recall from my Cooper S that a softer bearing surface as in the
> | Vandervell's for eg. were more desirable in order to prolong the life of
> the
> | journals.  Obviously there is a trade off, too soft and you have to do a
> | bearing rebuild every few years, and too hard etc etc.
> |
> | Has anyone ever used the bottom bearing for both top and bottom?  Any
> BTDTs
> | to offer.
> |
> | TIA.
> |
> | Colin
>
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