General Piston Bore (up) question?

[mr500]

Hi, On my aircooled Cinq 500 the standard bore is 67.4mm

I need new pistons. I can get a set on Italy Evilbay. Vendor lists at 68mm.

Does this mean these pistons are 'rebore' size or does it not matter about .6mm? .6 don't seem a lot to bore out. I suspect they won't fit but would like confirmation...

cheers

 

[richcinq]

0.6mm is a lot. That would need a rebore to take that piston size.

Rich.

 

[Oldschool]

You also need to bore them to the right piston tolerance, which means you need to get the pistons, take them to the workshop and llet them bore them out. Preferably buy them as a set rather than individual as they then already balanced as a set.

 

[mr500]

I thought as much. Cheers. The pots are fine. Just need an hone.

Will search for 67.4's

Or get a set of 650 barrels and pistons.. For that i'll need a set of 10mm spacers to sit under the barrel as they're shorter. Anyone know who can make a set of these rings?

Here's the kit on Ebay Italy should anyone be interested 160201119154. I think a Cinq was sold in Italy with an air cooled panda/126 engine (anyone confirm). So all a bit relevant oddly enough.

 

[fingers99]

Or get a set of 650 barrels and pistons.. For that i'll need a set of 10mm spacers to sit under the barrel as they're shorter. Anyone know who can make a set of these rings?

Just about any precision engineer (or anyone that reconditions engines). Best to get this done locally. Ring around yellow pages or ask decent independent garages who they use for machining.

 

[mr500]

Cheers.