Hi group!

I'm restoring a vintage Triumph motorcycle and discovered that the
alloy cylinder block (Wellworthy, I believe) is cracked, near the
exhaust ports, through the sleeve and cylinder block.

Replacement sleevers are no longer available from Wellworthy and I
would like to make new ones to press in after welding the cylinder
block. My question is: where would I find suitable cast iron pipe for
making the sleeves? I have access to a lathe and milling machine, as
well as welding capability.

The intent is to restore this machine but not as a daily rider. That
said, I would rather do the job correctly.

Thanks,
Norman C