Oil/Water Heat Exchanger Schematic

[pedrocamp]

I recently acquired an oil/water heat exchanger (cooler) from a 250 to fit to my 68 230 W110 with an M180. I have a Kuhlmiester AC and the engine runs a little warm while cooling me. Would anyone have a schematic, or a link, as to how this was plumbed into the 250? I have searched the web and EPC and can find no clear complete view of this. I will have to fabricate or locate the Ts or Ys to splice it into my system. Thanks.

[pedrocamp]

Should a Y be added to the line from the head to the heater cores and another Y at the water pump inlet, the pipe that returns from the heater cores and includes connection to the water tank? Thus water from the head is diverted to the oil/water heat exchanger and then back to the pump to be recirculated through the engine once again. When the heater valves are open both paths are open to water flow. Should the cooler have a shutoff or thermo valve to prevent flow to the exchanger during the winter to promote heater function? Actually my heater works so well in NC that I never run it at full capacity. Should the outlet of the heat exchanger return to the top of the radiator to dump heat picked up from the oil through the rad? I am sure an air-oil cooler may work better, as added to the 280s by the factory, but I do see a benefit to the added water and oil capacity, and thus heat carrying capacity, and thermal mass of the unit itself in keeping my engine cooler. Thanks for any advice or experience you can share.

[Squiggle Dog]

Nifty! I used to have one of those, but sold it. Now I wish I had kept it because my roommate and I moved to Phoenix, Arizona, and I'm putting air conditioning into his 1965 220S, so it could probably use all the cooling it can get.

[Squiggle Dog]

And here is the fitting that screws into the engine block:

[pedrocamp]

I did see your ad a while back which made me decide to get one at some point. I managed to get a deal on a small lot of parts that included a cooler but no fittings, Ts or Ys. Mine has a partial stainless braided flex line though that connects to the forward oil connection. Thanks(!!!) for the picture of the block fitting, makes sense, I will see if I can get one used or from MBCC.

[pedrocamp]

Squiggle, where did you find the above diagram on the EPC? What MB model is that from? Thanks!

Ps, would love to see a pic of your wagon.

[Squiggle Dog]

It's under 108012 250S USA, Maj. assy M - Engine, 20 ENGINE COOLING SYSTEM, 001 ENGINE COOLING, second diagram.

Here are current pictures of the wagon. It's a long-term project, but when completed it will be my daily driver.

[pedrocamp]

Thanks! That'll be a very cool wagon when it's done, aren't those 111 fenders? The 110 too far gone? Kuhlmiester?

[Squiggle Dog]

I had been wanting a W111 wagon for many years, but they are so rare and expensive. I got this W110 for cheap on craigslist and the entire unibody is rotten, so I figure I will get a rust-free W111 sedan with a sunroof and transplant all the wagon sheet metal onto it. The original W110 fenders were rotten and there was almost no original metal left on them (it was mostly sheet metal screwed in and covered with body filler, as is the entire lower portion of the vehicle). I had a W111 front clip from a 230S I parted out, so I put it on. It does have a Kuhlmeister, yes.

[pedrocamp]

Great project!

Actually I was trying to find the second diagram with the block fitting, I found the first diagram but that shows a head fitting. Is the part number for the fitting 127 200 04 56?

[Squiggle Dog]

Originally Posted by pedrocamp

Is the part number for the fitting 127 200 04 56?

That is correct. And the part number for the seal ring is 007603 030100. The part numbers are located under Maj. assy M - Engine, 01 ENGINE, 001 ENGINE HOUSING.