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Old 02-09-2015, 01:04 PM
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Stretch Stretch is offline
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Join Date: Sep 2009
Location: Somewhere in the Netherlands
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Quote:
Originally Posted by DeliveryValve View Post
You sure about this? I understand it differently....



Mercedes tries to machine all the bores the same. No difference between cylinders, but what happens after the machining process there are slight variances in the bore. The factory would then choose a group of pistons out of three groups that best matches the cylinder. This is not a repair group. But straight group selection from the factory.

617.95x info..
Group 0 = piston dia. 90.845-90.855 mm = cyinder dia. 90.898-90.908 mm

Group 1 = piston dia. 90.855-90.865 mm = cyinder dia. 90.908-90.918 mm

Group 2 = piston dia. 90.865-90.875 mm = cyinder dia. 90.918-90.928 mm


p/n 6160111210 Replacement Cylinder liners are rough honed to 89.9 mm.
I think that was what I was told by the machine shop when I got my block done.

From a machining point of view I can't see how such a great change in bore would occur from one cylinder to the other. From what i understand the casting of pistons is more problematic than boring holes. That's the reason for the grading of pistons.
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