On Sat, 05 Jul 2008 09:34:26 -0700, Tim Wescott
wrote:

Roger Shoaf wrote:
"Tim Wescott" wrote in message
...

the original was allowed to run too lean, overheated, and
now cylinder and piston are slightly oval; since the piston is free to
rotate on the rod you can run it for just a little bit before it binds
up).

Not to stop you from making a new cylinder, but I am curious, what would
happen if one were to get a ball bearing the right diameter and press it
through the cylinder? (Kind of like when they re-size brass cartrages prior
to reloading.)

With the equipment I have in the shop right now? Probably a stuck ball
bearing, possibly covered blood and lonely while I take a trip to the
emergency room. I'm not sure that it wouldn't mangle the push end of
the cylinder, even with the 'right' equipment.

I hadn't thought of ball-forming the old cylinder. If I were seriously
interested in getting the engine working with the least work I'd be
searching out a NOS COX cylinder/piston set. Or I'd be asking just how
to go about honing, lapping or otherwise cutting the cylinder back to
roundness so I could build a slightly oversized piston.

The truth of the matter is, however, that before I go cutting out the
dozen or so different parts of a from-scratch working engine, I'd rather
just try making the five needed for a cylinder/piston set.


The normal way to machine a cylinder such as you describe would be to
rough machine the bore; finish machine the bypass areas and then
finish machine the bore.

For finish machining you might look into adapting a Demril tool as a
tool post grinder which would make it easy to grind the bore to
finished size.


Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)