I think all the 617 engines had oil cooled pistons. My engine is the 617.950 and according to the "oil circuit" diagrams from the manual, my engine has them as well. Also each lobe on the cam has a dedicated oil feed, as well as each cam bearing. Along the lines of "over-engineering", The oil filter housing is a lot more than just that. If everyone can picture their oil filters, the lower portion is used when the oil temp. is below 110 c. Once the temp gets above that the oil is filtered through the finer filter that makes up most of the filter. All this temp. sensitive filtering is done by the oil filter housing. Also it directs oil to the oil cooler, again depending on the oil temp. If anyone has the manual, take a look at it, it's amazing how well though out this seemingly simple device is. All along I thought it just held the filter.

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1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member