| Listed in parts books | Not catalogued by year yet |
PISTON SET A7+040 1947-50
Piston set for the 1947-50 BSA A7, ground to +040 oversize.
This is a piston set for the BSA A7, sized at +040 oversize, covering the 1947-50 production span. It's a BSA part, not a Triumph one, despite showing up in our system under a JRC-prefixed number — the description is plain about what it's for.
Read more
The +040 marking means these pistons are ground to a specific oversize for a rebore, which is standard practice when a cylinder has been machined out past standard to clean up wear or damage. If you're working on an early A7, matching the oversize stamp to what your barrel has actually been bored to matters more than anything else here.
We don't have much more detail on this one beyond what's in the description. Give us a call and we'll confirm what's in the set and that it matches your engine before you order.
Sorry if we got something wrong here. If you think this information isn't correct, .