500 or 600 cases?

GSAX1 · Post by **GSAX1** » Fri Nov 23, 2007 8:36 am

How can best I see if a set of crankcases for a mid-fifties twin is 500 or 600? Will there be a difference in cylinder spigot diameter, if so what is it for 500?

Thanks for any help.

Michael

Biscuit · Post by **Biscuit** » Fri Nov 23, 2007 9:33 am

Well according to the spares list, 1956 & 7, they are the same part number.

GSAX1 · Post by **GSAX1** » Fri Nov 23, 2007 10:28 am

Hmmm. Strange. Surely the 600 cylinders had larger diameter, and that would also be the case for the spigot diameter?

Merlin · Post by **Merlin** » Fri Nov 23, 2007 10:50 am

Could have a longer strokewith the same diameterEdited by - Merlin on 23 Nov 2007 10:51:28 AM

Biscuit · Post by **Biscuit** » Fri Nov 23, 2007 10:56 am

Same stroke Merlin, larger bore.

One can only assume there was enough meat on the spigot. Looking at a pair of 600cc. barrels, the spigot is quite thin.

ajsph · Post by **ajsph** » Fri Nov 23, 2007 4:11 pm

The Barrels for a 500 from 1956+, have the same diameter as the 600, on the half lenght of the spigot. The case are the same.
Poul

laxy · Post by **laxy** » Sat Nov 24, 2007 8:29 pm

Is there an engine no. stamped on the front of one half? This would identify the cc
For example, after the year number,20 or G9 = 500cc 30 or G11 = 600cc
Hope this helps.