Quote:
Originally Posted by Bio240D
Hi Lucas,
I actually ran a vacuum type IP from a 615 on my 616 for a bit (pre turbo) as an experiment. It was a drop in swap, so I'm assuming you could run the centrifugal 616 IP on the 615.
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I know I'm late to the party but there is a problem with installing the centrifugal pumps (MRSF and MW) on early engines. The early OM615 and OM616 engines use a pneumatic pump with a separate oil supply. The oil in MRSF and MW pumps is supplied by the engine. Early engines don't have a provision for supplying oil to the MRSF or MW pump.
The MRSF (euro) pump gets its oil from the IP drive shaft. Later OM615 (only euro) and OM616 (W123) engines have this provision. To convert an early pneumatic pump engine to this oiling system requires the later style (type 3) timing device, IP driveshaft and block bushings. The type 3 IP driveshaft has drillings to supply oil through the IP shaft nose. The rear IP shaft bushing in the block has a slot that is part of this oiling system. The front bushing is also different due to an inside diameter change designed to prevent the accidental swapping of parts between types. Despite these changes the block drillings are the same between early and late engines.
The MW pump gets oil from an external oil line that connects to a tap on the block. All OM61x engines have a drilling in this location. This drilling is for the oil gallery that supplies the IP driveshaft etc. However only later (W123) OM615 (euro) and OM616 (US and euro) engines are machined for a banjo bolt. The earlier blocks are plugged. It may be possible to drill the plug and add a banjo bolt but it would be near impossible with the engine in the car. Another solution would be to get the oil supply from the oil sender line.
Unfortunately however, the MW pump will not physically clear the large threaded water jacket plugs on the early blocks. The MRSF will clear them. I have one OM615 factory replacement engine that has the later style (W123) cup plugs but every other W115 OM615/616 I've seen has the large threaded plugs. Grinding the plug may solve the problem but these plugs are gasketed with a straight thread rather than a pipe thread. If the thickness of the head is reduced too much it may leak. Another issue with the MW pump is the mounting angle. Because of its large size its rotated away from the block and on a W115 that gets tight. The factory used the MW in a W115 on the OM617 so it should be possible. Consider though that the OM617 in the W115 chassis is positioned differently.
So basically you can swap any one of the three pumps onto a LATE engine ONLY. When using the M pneumatic or the MRSF the external oil supply for the MW has to be plugged and you're done. All late engines have an IP shaft that will supply oil for an MRSF even if the engine was originally equipped with an MW. If there is any doubt about oil supply remove the vacuum pump and look for a BOLT attaching the timing device. If your timing device is retained by a nut it's either a type one or two and it WILL NOT supply oil to the MRSF.
To convert an early engine you will need a late style IP drive setup to supply oil to the MRSF or an external oil line for an MW. If using an MW block clearance will be an issue unless you're fortunate enough to have cup plugs in the water jacket. If you go with an MRSF and swap in a used IP driveshaft get it from a late (W123)OM616. Be sure to get the oil pump driveshaft since they have run together and need to be replaced as a pair. In fact, the factory won't supply them as separate parts. The NA OM617 uses the same setup but that engine uses a heavy duty oil pump which causes the oil pump drive shaft gears and bushing to wear faster. The ones I've pulled have shown a lot of wear as compared with OM616 engines with similar mileage. Cooljay had a post about this very problem. OM617 Turbo engines have a chain drive oil pump so they don't have an oil pump driveshaft.