Author Topic: a7 plunger or rigid frame  (Read 1909 times)

clive40uk

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a7 plunger or rigid frame
« on: 22.09. 2007 18:10 »
Hi
I have  an A7 basket case the problem is the engine is 1949 and the frame is 1957, I would rather put the engine into its correct frame rather than modifying the younger frame. So my request is : has anyone got a plunger or ridgid frame that this engine can fit into without any mods?

Many thanks

Clive

Offline terryk

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Re: a7 plunger or rigid frame
« Reply #1 on: 26.09. 2007 12:14 »
Hi Clive, If you were in Australia, I may be able to help you. Keep watching ebay frames are on there from time to time. A 57 model frame is swinging arm and 49 is plunger or rigid if the engine you have came out of a 57 frame its the wrong one are you sure the 49 is not just part of the engine number. Plunger engine cases have the inner primary as a part of the drive side crank case. You probably know this but just in case you dont. regards Terry K in Australia.
1950-53 A10 rigid/plungers, 1958-61 A10 super rockets, 1947-50 A7 longstrokes, 1949 Star twin,
1951-54 A7 plungers, 1940s M21, WDM20s,
1948-50s B33s rigid/plunger/swingarm, 1948-50s b31s rigid/plunger/swingarm

Offline Beezageezauk

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Re: a7 plunger or rigid frame
« Reply #2 on: 26.09. 2007 19:28 »
Hi Clive, 

I think what you probably have is an A10 basket case from 1957 and a 1949 A7 engine.  The plunger A7 was discontinued in 1954 but the A10 plunger was made until 1957.  BSA generally used the same frame numbers for the A7 and the A10 so, with the exception of the A10 Super Flash, all A7 and A10 frame numbers started with a prefix letter and then "A7". 

Perhaps you might consider looking for a 1957 plunger A10 engine instead of a 1949 A7 frame.  You could then have a Plunger A10 with a spare A7 engine.......just a thought!!

Beezageezauk.