Hi everyone,
Try as I may I can't seem to find any oversize pistons for my BSA Sunbeam B2 (250 twin), same as the Triumph Tigress TW2 scooter. Big end shells would be great too. every thing else seems fairly straight forward as far as bearings, seals etc, just these items stalling my restorations.
Please Help if you can.
Marko.
I had to give up on this search recently also. I managed to find some NOS standard size on Ebay and am having the barrels re-lined to suit. There were some on Ebay yesterday.
Good luck
I used to have a 250 Sunbeam and came across a fix to this, although I can't find the article now. There was a way of fitting Hillman Imp pistons into a sunbeam with minimum mods. It used to be on the BSA sunbeam forum but I think that is now gone but I am sure it would turn up with a bit of searching
Yes, there is a data base some where detailing the interchangeability of pistons by gudgeon pin dimensions, locations and diameter etc. I remember 40/50 years ago fitting Vauxhall viva pistons into a Fiat 500 - I had to hacksaw a fairly large portion of one of the skirts off to prevent fouling the little push rod which went internally from the cam on one side of the block to the petrol pump on the opposite side! There was a company called Gordon Moss Engineering in Ledbury who provided me with the info!
I found the conversion sheet, eventually. It was for a C11G rather than a Sunbeam :-\
However when I had the Sunbeam the only parts I found that I could not get even secondhand were the parts for the electric start conversion (just the motor) but there were alternatives for that too.