Scooterotica

had a SIL cast barrel bored out to 70mm
the windows cut in the cylinder spigot at the bottom where the transfers go were thin so cleaned them up - now the cut outs are quite high and above the deck height

does this matter?

cheers
mick

I've got a SIL barrel at the engineers awaiting to be bored to 71mm but they have voiced concerns over the transfers.. got any pics?

They said it would fall in half! Cant see it, maybe go up the barrel a bit, shouldnt effect the running but I did notice that the barrel transfers cut back in towards the bore.

the scooter shop that did it said it wouldnt affect the running but thought i'd ask on here as its a great source of info

wot have you done to my barrel streakyyyyyyyyyyyyyyyyyyyyyy :biggrin:

Are them barrels ok to take out to those sizes, 70 and 71 are very big numbers

they are hard cast iron so wont get weak - i hope lol

any photos ??

Did you get any pics of it at 71mm mate, before fitting?

If you read Mr.Websters tuning manual he says you can shorten the wall to match the piston cut-outs when the piston crown is just opening the transfer ports,something I tried a few times in the 80's.Nowadays I just grind the knife edges down evenly to bring back the thickness after boring to 70mm+.

i cut them well down on my tunes