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Author Topic: Matching crankcase numbers  (Read 158 times)

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Online bsa171

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Matching crankcase numbers
« on: February 13, 2016, 04:05:31 AM »
I see some crankcases for sale on Ebay that they say have matching
crankcase numbers.   I have a pair of C10 & C11G  crankcases that
I cannot find any numbers on.   Where are these numbers supposed
to be located.  Did the factory put these numbers on all crankcases ?

John

Online MilitaryRon

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Re: Matching crankcase numbers
« Reply #1 on: February 13, 2016, 06:32:50 AM »
I have BSA's with the numbers stamped on the front lugs. Any machining that is done, like the boring's for the main bearings is a matched pair. I've also seen the stampings inside the cases on some makes. Ron

Online timsdad

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Re: Matching crankcase numbers
« Reply #2 on: February 13, 2016, 08:55:08 AM »
The numbers are sometimes on the front engine mounting castings down at the bottom front. Wherever they are, they'll be close together, one on each half, and on a thick bit of casting.

Like Ron said, I don't know of any factory that didn't stamp the two casing halves, usually with a simple two or three digit number, as soon as the cases had been machined as a matched pair.


Ray
Just a motorcyclist.

Online Owen

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Re: Matching crankcase numbers
« Reply #3 on: February 13, 2016, 02:55:29 PM »
Here you go.
1945 C10 & C11
1953 C10
1953 C11 x 2
Still looking for an Original 350 side valve C12

Online bsa171

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Re: Matching crankcase numbers
« Reply #4 on: February 13, 2016, 03:42:34 PM »
Many Thanks All, for the good detailed information.  I will examine
my two sets of castings more closely.

John