Pic. 71. Location of the oil spray nozzles of the piston cooling system
Listed below are some of the design changes made to the 601 and 602 family engines in case you are considering replacing some parts from a similar engine type designation. Although the engines have the same designation, this does not mean that they are exactly the same. Since 1985, the diameter of the crankshaft bearing bores has been reduced by 2 mm. The diameter of the fixing bolts of the crankshaft bearing caps has been reduced from M12 to M11. The bolts have double hex heads. Since these are flexible bolts, their length should not exceed 63.8 mm if you are going to reuse them. The mating surface of the cylinder block in contact with the cylinder head has also been modified, so such blocks must be used with correspondingly modified heads. The drain plug for the liquid from the cooling system now has an M18 thread instead of M14, as before. The points of oil supply to the spray nozzles of the piston cooling system are made on the new engines on the right under the cylinder liners. On fig. 71 shows the location of these oil spray nozzles. If you are going to install a cylinder block from an old engine on your car, then it must be equipped with oil spray nozzles to cool the pistons. If you are in doubt about anything, then contact a Mercedes-Benz workshop, as it has all the necessary technical documentation.