Had an email at the weekend from BMW regarding a Specialloid piston that they have in their collection (the respondent didn't say 'which' collection) in Germany.
I had a look through our Specialloid catalogue for the reference he quoted, but couldn't find anything. It's a 220mm piston, so initially I was thinking large diesel, as Allen were a Specialloid customer, and the reference begand with an 'A'.
Specialloid 'generally' used the customer's initial before the reference number, although this did go out of the window later on.
Anyway, I asked the guy if he could give me more details of the piston, gudgeon pin size, number of rings etc etc., and he came back today with that info plus some pictures which I will put up on the website tonight, subject to him agreeing.
The gudgeon pin is only 20mm diameter, so that immediately puts it out as far as an internal combustion engine piston goes, and there is a company listed who make vacuum pumps, some with larger than 220mm pistons, so I think this is one of they.
It also could be a charge pump for a two-stroke diesel/oil engine, so that's a possibility I will look into, as Crossley are listed in the Specialloid catalogue as well.
Peter
-- Peter A Forbes Prepair Ltd, Luton, UK snipped-for-privacy@easynet.co.uk