Thinking about rebuilding the motor in my 320 3066 since this is a sleeve less engine what are the chances of haveing to get it rehoned starting to use oil 12000hrs. Its also abit hard starting when it gets colder outside so thinking its getting worn my 315BL approx same hours fires right up.
Absolutely are going to have to run a glaze-breaker, you need a proper surface for the rings to seat. Bigger question is are you going to need it bored. Only a good machinist will be able to tell you that. I'd give it a 50/50 on that.
Thank you dont think you can get reman might look for a realy good used one might be needle in a haystack.
You should be able to check cylinder taper and out of round with an inside mike or bore gauge. An engine book will give you the specs. Shimmy1 is correct on the glass breaker. As a final check before assembly, I check the end gaps on the rings as well before installing them on new pistons.
Have you checked the batteries, earthing etc? Can check the cylinder compressions before ever considering engine overhaul. If the diesel engine listings are up to date, you can get the full range of engine conditions - new, reman, recon, runner, parts, exchange etc. or upgrade to a cummins 6 BT HeavyEquipmentForums
The cylinder bores will most likely be “egg” shaped. I don’t know what they offer for oversized pistons. They do offer sleeve kits. A good machine shop won’t have any problems boring and installing sleeves.