+- STD (https://www.superturbodiesel.com/std)
+-- Forum: Tuning (https://www.superturbodiesel.com/std/forumdisplay.php?fid=6)
+--- Forum: Engine (https://www.superturbodiesel.com/std/forumdisplay.php?fid=7)
+--- Thread: Om612 crank into Om605 (/showthread.php?tid=8576)
Om612 crank into Om605 - Eric78 - 05-15-2024
How difficult is it to get the OM612 crank into an OM605, keeping everything else the same apart from after market OM612 forged rods? What mostly matter is whether the main journals are the same on both cranks.
RE: Om612 crank into Om605 - Niko - 05-16-2024
Well, the rod and journal bearings fit. Not sure how it is axially .
Do keep in mind that the 612 rod bearings have the locking pin located on the wrong side for a 605 rod . Made that mistake recently .
What about the compression ratio ? How do you plan on keeping that ?
Afterthought :
Going by the numbers at TDC you have 22.7cc stock . With the 612 crank you'll end up with 524.8cc of stroke , so if the block and head height remain the same a 1.85mm gasket would do (1.65 gives 23:1). Not sure how sensitive those engines are to CR, guessing not much
RE: Om612 crank into Om605 - Eric78 - 05-17-2024
I was planning to keep 22:1 compression.
RE: Om612 crank into Om605 - baldur - 05-22-2024
The way a friend of mine solved it is he used OM612/OM613 rods and machined bushings for the small end to fit the smaller wrist pin of the older engines.