OzVMX Forum

Marketplace => Wanted => Topic started by: Skivi on June 16, 2012, 07:09:14 pm

Title: Wanted: 40's/50's BSA pre-unit singles bits n bobs
Post by: Skivi on June 16, 2012, 07:09:14 pm

G'day All,

I'm a young bloke with ambitions of racing my rigid '52 BSA B33 500cc OHV on the dirt track however I need a few bits to complete it (and also a '49 BSA M21 600cc SV which I'm building for my fathers 60th birthday present)

Wanted:

Fork legs to suit 8” half width brake
B33 Barrel (pre '53 style)
plunger/rigid model 4spd gearbox 
Lucas MO1 magdyno (dead or alive)
Alloy head to suit M20/M21 (can swap for a very good cast iron one)
Engine drive sprocket/cush drive assembly (4 lobe type)
inner and outer primary drive cases (yes those horrible pressed steel ones)
petrol tank to suit M20
if anyone has a set of M20 girders let me know


best to contact me on 0437 9525 87 after 6pm weeknights or any time on weekends, otherwise nick.umek{AT}gmail.com

also happy to chat about BSA's if anyone else is building them, i have a fair bit of literature on them kicking about which I'm happy to share.

I'm down in Melbourne

-Nick

Title: Re: Wanted: 40's/50's BSA pre-unit singles bits n bobs
Post by: GMC on June 16, 2012, 09:28:14 pm

So how do you tell the difference between a M20 & a M21?

Title: Re: Wanted: 40's/50's BSA pre-unit singles bits n bobs
Post by: pancho on June 16, 2012, 10:56:26 pm

 longer stroke

Title: Re: Wanted: 40's/50's BSA pre-unit singles bits n bobs
Post by: Skivi on June 17, 2012, 09:16:14 pm

yep, The main difference is in the flywheel, on the M21 the crankpin pin is located further from the centre of the flywheels,
thus giving a longer stroke, the conrods are the same, as is the piston diameter, but the gudgeon pin sits higher on the M21 piston, the Barrels are also the same except for a slightly larger input port, and a bigger carb on the M21.

Title: Re: Wanted: 40's/50's BSA pre-unit singles bits n bobs
Post by: matcho mick on June 20, 2012, 11:55:33 am

http://www.ebay.com.au/itm/vintage-bsa-inner-primary-chaincase-65-7578-M20-M21-B33-B34-B32-B31-C10-C11-C12-/130715811759?pt=AU_Motorcycle_Parts_Accessories&hash=item1e6f44ffaf