Increased production costs and other overheads have meant that a price rise has become inevitable for my 90mm pistons.
These pistons are a flat top design and can be fitted to either a B33 to produce 570cc with a standard crank or in the sidevalve motors, 720cc when used with an M21 crank.
The piston specification far exceeds the original as they are forged, not die cast and a modern ringset is fitted with a 3 piece oil scraper ring. Material is high silicone alloy so expansion rates are low for a piston of this size. Gudgeon pin dimensions are as the BSA at .750" diameter. For sidevalve applications a post 1951 'unlinered' barrel is required. For B33 applications either 'big fin' or 'small fin' barrels are suitable.
Particularly in the OHV motors they can be safely used when the engine is subjected to virtually any amount of further tuning.
Price will be £170 plus postage.
If there is sufficient demand to warrant the purchase of a batch I will get this underway so please let me know if you are interested....Ian
email (option): ian@wright52.plus.com
Hi Mick..To be confident of a good quality casting you need the post 51 barrel. BSA used good liners in not so good basic castings and good castings without liners...Ian
email (option): ian@wright52.plus.com