Hi all,

There is a piston with stated PN: 65-1693
and it said to suit both M33 and B33,
So is it B33 "Short rod"?
I could not find this number anywhere...

Thanks,
Noam.

email (option): noam10@gmail.com

Anyone?...

Thanks...

email (option): Noam10@gmail.com

Hi Noam...I can't find it in my lists..The nearest to it is 65-1692 which is a standard size 6.5-1 M33 piston for 53-55...So a 'short rod' type I think..This is a difficult one though as it is right on the change period from 'long' to 'short' types. Late 53 (August onwards for the 54 model year) would be short rod... From 55 onwards the M33 was 7.5-1 (as it was from 49-52). At 6.5-1 it should be flat topped.
Is the number you have quoted stamped on the piston crown or cast into it?...Ian

email (option): ian@wright52.plus.com

Hi Noam...It is a short rod piston..If you want one for an oversized M21 you will need a long rod one...Ian

email (option): ian@wright52.plus.com

Hi Ian,

Thanks allot for the info !

The number was given by an eBay seller.
I was looking for a B33 long rod piston as you advised,
and saw this one, which was not clear whether it was short or long.

http://www.ebay.co.uk/dsc/i.html?_ipg=200&_psize=3&LH_TitleDesc=1&_jgr=1&gbr=1&_fcid=100&_from=R40&_sacat=0&_nkw=65-1693&_trksid=p2045573.m570.l1313.TR0.TRC0&_osacat=0&_odkw=bsa+m20


I have all the parts for a 630cc engine- (B33 piston)
Most are even NOS:
(bottom case complete W/ bearings, conrod, conrod bigend bearing, piston)

The piston I have is a bit heavy, oversized and domed,
(Actually, the oversize would make it a 650cc, rather than 630…)
so I thought to give another try to get a flat standard one,
But I guess I will go with the one I have..

Thanks again,
Noam.

email (option): Noam10@gmail.com