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+--- Thread: Piston - to - cylinder clearance dimension (/showthread.php?tid=6188)
Piston - to - cylinder clearance dimension - Jetmugg - 01-31-2015
What kind of piston-to-cylinder wall clearance are you guys running in your Mercedes OM60x series engines?
Steve.
RE: Piston - to - cylinder clearance dimension - barrote - 01-31-2015
well my friend that is milion dólar question
my 605 last time i checked was almost 1 mm apart 
normal nrs are .25mm as a max.
at www.124zone.com u can find MB repair manual, somewhere in there u have the nrs.
regards
RE: Piston - to - cylinder clearance dimension - [486] - 01-31-2015
For piston/wall clearance, .0018"-.0023" per inch of bore diameter is a good safe range. Shoot for the looser end for higher power builds, so the pistons have room to expand as they get hot.
RE: Piston - to - cylinder clearance dimension - F.R.A.S - 02-01-2015
Don't feel like this is Mercedes spec am I right? Source on that?
(01-31-2015, 06:03 PM)[486] For piston/wall clearance, .0018"-.0023" per inch of bore diameter is a good safe range. Shoot for the looser end for higher power builds, so the pistons have room to expand as they get hot.
RE: Piston - to - cylinder clearance dimension - [486] - 02-01-2015
(02-01-2015, 05:25 AM)F.R.A.S Don't feel like this is Mercedes spec am I right? Source on that?Oh right, forgot that that's more toward direct injected engines, they put a lot more heat into their pistons than IDIs. Probably okay to go a bit tighter on an IDI.
(01-31-2015, 06:03 PM)[486] For piston/wall clearance, .0018"-.0023" per inch of bore diameter is a good safe range. Shoot for the looser end for higher power builds, so the pistons have room to expand as they get hot.
Just a general specification found looking around at streetable high performance diesel engines (all direct injected though). The numbers I ran into on dedicated pulling engines were even looser still. Factory is something like .0003" per inch. I'm running something like .0014" per inch on a pretty hot TDI build, but that has oil channels in the piston crown.