I believe the 330 starts at 76mm and usually has 4 overbores, so it can go up to 78mm maybe a little bit more.

 

Thank u . I found a cylinder bored to 77.5 . I don't think it worth the money now.
Thank u again.

 

If your talking about the cylinder I have on eBay it has been nikasiled. So that pretty much means that it will never need bored again.

 

Yeah, 77.50mm would be last bore for a 330 jug, because if you try to go up to the 78mm, the area of the sleeve at the top between the bore & the o ring groove is to thin & pieces will break off of the sleeve. You might could try it & it probably will run ok the first time out, but once it cools off, the top ring will be stuck from those little pieces getting jammed up between the dome & piston.
That cylinders gonna need sleeve replaced, but by the time all the work is complete & ready to bolt back on, will almost be as much invested as you can buy a new ESR top end kit.
Now if theres somebody can do the sleeve replacement cheaper than normal, might be a good deal.
Neil

 

No a guy on Craigslist. Thank ya'll for the information.

 

Depends...some started life at 75.50 MM (most recent batches), most started at 76 MM...on the ProX; the last bore over the cylinder was designed for is 77 MM...you can push it to 77.50 MM, however; the o-ring glad will become to thin on the bore side and eventually crack and fail.

Carlos