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#859021 09/21/21 1:37 pm
Joined: Apr 2003
Posts: 51
R
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R
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Quick question please?
Can B31 cylinders be used on a B33 bottom end? Any problems _if_ they can physically be mounted on the cases?
Thanks, Ron

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Joined: Apr 2003
Posts: 51
R
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Quick question please?
Can B31 cylinders be used on a B33 bottom end? Any problems _if_ they can physically be mounted on the cases?

Or; Put another way. Can a B31 cylinder be bored out and used on B33 cases???
Thanks, Ron

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Hi Ron
Yes the crankcases are the same so the B31 cylinder will fit
But you cannot bore the B31 cylinder to the 85mm size of a B33
Some people bore the B31 cylinder to 76mm and use a Triumph piston to get near 400cc
Not exactly straight forward as I believe the crank needs re balancing to avoid bad vibration ??

John

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crank does not need to be balanced, also you can take out to 79mm b44 piston


A7, A10, B33, B31, A65, C15, T100
Bantam
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