Anyone install the Mercedes Benz electrically controlled fan clutch on a 403 yet?

[Mike Perez]

Tom,

Great job on the Mercedes fan clutch. I have a question or two if you could entertain me. My particular engine is being built to run a modern GM
computer with Multiple-port fuel injection. The GM computer has the capability to start and stop a fan based on parameters it already knows like A/C
status, coolant temperature, etc... So while the Mercedes kit that Jim sells is great; I just don't need all of the electronics. Is there a way to
get a flange adapter from either you or some other source? I'm not sure Jim will use sell me just the flange adapter.

The second question is that I noticed on one of your pictures on the Motorhome picture site, that you used a tether of some kind back to the water
pump. I may have a serpentine drive setup in the works, so I'm curious what the point of that tether is and if it is necessary.

Thanks in advance.

Mike Perez

 

[john r. lebetski]

As far as depth in the shroud, the old type fan needs at least 50% ot blade tips outside the shroud as the air flow is largely outward off the tips.
The new plastic fan has it's own ring at the tips so it should work fine with more depth at least in theory. I think that Chinese clutches have been
the driving force to be the necessity for the invention. Bob I think you are over exaggerating the time factor for temp rise. It's only a couple
seconds difference in reaction, the biggest is the time for the air temp change to heat/cool the thermal bimetalic spring. I did testing with a dual
input digital thermometer on my stock coach. One probe between rad and fan and second one on water outlet. The water probe only varied a few degrees
tracking the stock dash gauge closely in a variety of conditions from idliing to intown to highway. The air probe swung wildly with change of
conditions. When pulling away the temp would go way up as more air was being pulled through the rad and transfering stored heat, but then quickly
dropped as that was disipated and equilibrium established. During in town driving the swings were surprisingly large and extreme while the denser
liquid temps barely moved. So it's true the signal for the clutch is all over the place. This is part of the somewhat erratic clutch behavior some
have especially if you are right at the toggle point. Right now my Delco is satisfactory, but it would be nice to be able to turn it on sooner on a
long grade instead of watching the guage move and hoping it finally comes on soon. Also it would be nice to engage it when descending in S to add
just enough drag to lessen having to brake apply to prevent engine overspeed. I'll look into Jims kit when the time comes.
--
John Lebetski
Woodstock, IL
77 Eleganza II

 

[Bob Dunahugh]

I put one on a 403 a year ago. It fits the 403 shroud perfectly with no mods required. But since the shroud is out. Make it into a 2 piece. Since it's electricity controlled. There has to be a tether because of the wires. My tether goes to my shroud. I thought that it made the wire routing simpler. If you want the adapter hub to put your own together. DON'T. Tom put a nice kit together. Easy to install. The system isn't as simple a system as you may think. As to it's electronics. I don't THINK it's as quiet as the original stock fan. But it moves a lot more air to cool the radiator much faster. Bob Dunahugh 78 Royale 403

 

[jim kanomata1]

I have over 15,000 miles on this kit on my 403 with 4.10 final drive. You
need the adapter nut / flange.
Tom Prior developed the kit and we are marketing the kit.

On Sun, Feb 17, 2019 at 10:22 AM John R. Lebetski via Gmclist <

> As far as depth in the shroud, the old type fan needs at least 50% ot
> blade tips outside the shroud as the air flow is largely outward off the
> tips.
> The new plastic fan has it's own ring at the tips so it should work fine
> with more depth at least in theory. I think that Chinese clutches have been
> the driving force to be the necessity for the invention. Bob I think you
> are over exaggerating the time factor for temp rise. It's only a couple
> seconds difference in reaction, the biggest is the time for the air temp
> change to heat/cool the thermal bimetalic spring. I did testing with a dual
> input digital thermometer on my stock coach. One probe between rad and fan
> and second one on water outlet. The water probe only varied a few degrees
> tracking the stock dash gauge closely in a variety of conditions from
> idliing to intown to highway. The air probe swung wildly with change of
> conditions. When pulling away the temp would go way up as more air was
> being pulled through the rad and transfering stored heat, but then quickly
> dropped as that was disipated and equilibrium established. During in town
> driving the swings were surprisingly large and extreme while the denser
> liquid temps barely moved. So it's true the signal for the clutch is all
> over the place. This is part of the somewhat erratic clutch behavior some
> have especially if you are right at the toggle point. Right now my Delco
> is satisfactory, but it would be nice to be able to turn it on sooner on a
> long grade instead of watching the guage move and hoping it finally comes
> on soon. Also it would be nice to engage it when descending in S to add
> just enough drag to lessen having to brake apply to prevent engine
> overspeed. I'll look into Jims kit when the time comes.
> --
> John Lebetski
> Woodstock, IL
> 77 Eleganza II
>
>
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--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502