Re-sleeving OM621?
 

Are there viable options for re-sleeving / new liners for OM621 piston cylinders? Would like to keep solid, original block and pistons and only change out rings.

Does this engine have removable wet liners like an industrial engine or are the cylinders part of the block?

If removable wet liners, you might be able to get Darton or some other companies to make custom ones.

If the cylinders are part of the block, these can be dry sleeved. This is a common practice with liners coming in many sizes.

Thank you. I would have to go w/ dry sleeve option. Great info to know.

Dry sleeve is the way to go. Any machine shop can bore out the cylinders and press in a universal sleeve, then bore to the desired size. They wear much less than the bare block, especially on the OM621 which is bad for cylinder wear.