Sanden AC compressor on 280C /M110 powered

[Frank Reiner]

cefalu:

In the event that your car was originally equipped with A/C, as appears to be the case, it is already fitted with an electric fan!!

[cefalu]

This is true, there is a pusher fan in front of the condenser.

Do you think this will be sufficient by itself? It does work. I tested it. But as I recall it turns on when the water hits a certain temp. I grounded the sensor on the block and it came on.

[Frank Reiner]

As a test, remove the engine driven fan, rig a temporary switch to ground the temp sensor (or the relay), and note the results when driving.
Or, as the Brits would say, "Suck it and see".

[cefalu]

I suppose I could use the same temperature switch on the block, and connect a relay to it for a "sucker "fan mounted to the radiator to replace the aluminum fan on the water pump.

I will remove the fan for a test drive and see how it goes.

[Palolo]

I tested the pusher fan ahead of the a/c condenser with no engine-driven fan mounted on my 180 280SE...

With the pusher fan running (I have a bypass-to-ground switch), I detected barely a hint of air moving behind the radiator, nothing compared to the flow of the stock puller fan, which gives a decent whoosh of air (note scientific terms for the different effects I felt with my hand). My car was stationary only, but after trying it and not noticing what I thought was enough air passing through the radiator, I didn't want to test it while driving in our hot weather. I know some engines can run ok with little airflow, but my M130 isn't one of them. YMMV.

(Side comment: If I were to replace my engine-driven fan with an electric puller, I would connect it to a digital controller such as the one Davies Craig makes. Granted, I would also like to replace my stock waterpump with their EWP for maximum benefit--it uncouples the water pump speed & flow from the engine RPM, and it also varies fan speed as needed, regardless of RPM, as well as running both the fan and the pump for a while after the engine has shut off. Davies Craig )

[Mike D]

See post #3.

The existing auxiliary fan is NOT sufficient for cooling of the gasoline engines. It will work on the diesels. The 100C sensor will NOT work for engine cooling. By the time it triggers, the engine is at the overheat point (100C=212F) and it can't catch up.

If you decide to go electric there are a couple of companies which make remote temp sensors.

I got mine from Mill Supply. It is adjustable and has a separate circuit which engages the fan when the A/C compressor is powered regardless of the engine temperature. It uses a probe which is inserted into the radiator cooling fins.

I use the 16" fan as a "pusher" on my M110 and the same unit as a "puller" on my M115. Never had an overheating problem and that is here in Tucson. You could modify the radiator shroud and go with twin 8"s or 10"'s as "pullers" which would be a work around with the water pump clearance issues on the later years of the W114.

The 16" pulls about 15 amps, the 8's pull about 6 and the 10's draw 9 or so. 14Ga. wire will handle the current but I used 12Ga. just because.

I've got a picture of the setup on a '73 M110 in a W114 somewhere on the board.

Installation of the controller is easy. Hot lead from the battery (the unit comes with its own fuse wiring), an "ignition on" lead, a ground, the fan wiring and the A/C compressor trigger. If you have a '74 or later model the power lead is right there on the fender well terminal block.

*found the post. The second picture is of the control unit.
http://www.peachparts.com/shopforum/vintage-mercedes/221466-fan-clutch-question-2.html

[Coolvibes]

The tips of the blades of the engine driven fan on my 1967 230, 6 cyl, have a substantial arc (quarter of a circle) cut out of them. I'm not sure if it's factory or not, but the car runs cool in hot Miami. Apart from balancing the fan, I don't see why this couldn't be done to the 110 engine fan as well to clear the compressor.

[Frank Reiner]

Originally Posted by Coolvibes

... I don't see why this couldn't be done to the 110 engine fan as well to clear the compressor.

Past tense applies; done 20 years ago; see post #11.

[cefalu]

For those of you following the sanden conversion, here are some pics of another M110 powered car that has the sanden compressor.

http://www.peachparts.com/shopforum/vintage-mercedes/340460-random-bushing-appeared-my-footwell-280c-m110-idle-control-issue.html#post3170183


Post #11 has some pics which show a notch cut off the fan tip.

[cefalu]

I have made a little more progress on my Sanden conversion.

I bought a new fan from Peachparts for $28.75. Part number 110-200-03-23-M202. The new fan has more blades than the OE blade, and is slightly thinner, so there is a bit more room between the fan and radiator. Incidentally, this fan appears to be a Mercedes part which had the logo ground off. There was still part of a circle which remained.

Then I made a cardboard template to mark the area I needed to cut off each blade. I used a peanut grinder to cut the notch so the blade will clear the clutch. I initially trimmed the OE aluminum fan blade but I like the plastic fan better.

Lastly I used a file to clean up all the newly cut edges.

But I have one last problem. The Sanden compressor I bought does not have the same connections as the York did. So I need to have new hoses made to match the compressor.

At this point it all fits up well, the OE fan belt size even fits perfect.