Just Be Cool… Be Cool man!

By: Bob Goodson
June 21, 2020

Author: Michael Yount

I ordered a 12″ medium profile (2.44″ thick) SPAL electric puller fan for the car.  Also ordered a Delta Current Control pulse width modulated variable speed controller.  I’ve used a similar combo (SPAL fans and DCC variable speed controller) on my V-8 powered 82 Volvo 242 for almost 20 years and it has worked flawlessly.  The DCC piece is particularly slick – it varies the speed of the fan (and the effective current draw) so as to keep the car at a set point temp that you can adjust.  With a 195F t’stat I’ll shoot for controlling somewhere around 200F-202F.  This should easily allow the fan to cycle off when the car is in motion.  You can also set it to run at 50% of max speed anytime the a/c compressor/clutch kicks in.  The DCC piece has soft starts and stops — meaning it ramps up and down in speed and doesn’t “shock” the system the way relay powered fans do.  I’m hoping this relatively modest fan (the biggest I could fit) and the controller will allow co-existence with my stock alternator.  If not — another post for an alternator upgrade.

With the radiator already out of the car from the cut-lower-hose-debacle — step 1 is removing the small pusher a/c condenser fan installed by the previous owner.  It’s small and covered maybe a 1/4 of the condenser.  No need for this with the new, bigger puller handling airflow over the condenser while the a/c is on.  You can see it behind the grill.  I’ll see if I can find an ebay taker for this one — make a good oil or tranny cooler fan.

Fan arrived — a nice piece, a common experience with my SPAL purchases.  And it appears the fit on the radiator is danged near perfect.

After playing with different bracket/attachment approaches, I finally decided that just going between the tubes/fins was the best approach.  At the bottom, the threaded fastener goes under the fins and between two tubes.  I put shrink-sleeve on the screw and made a rubber washer for going under the nut – so no metal-to-metal contact.  At the top of the fan, I just wedged a few fins far enough apart to get the screw through.

About a finger’s worth of clearance to the water pump pulley, just as expected when I measured before ordering the fan.

My Delta Current Control unit showed up. 

Install was dead simple – hot in, ground and hot to the fan.  And a connection to the A/C clutch so the fan runs at least at 50% speed whenever the A/C clutch is engaged.  The unit is adjustable – I set the adjustment as recommended in the instructions for the 195F t’stat I’m running.  Should control the engine temp around 200-205F at lower speeds when the fan is controlling.  Placed right behind the driver’s side headlight – one of the cooler spots in the engine bay.

I also took the time to use foam to seal all the gaps between the condenser and the radiator – so all air moved by the fan has to come across the condenser.  That will improve A/C operation.  With the radiator support back in place – you can barely see any of the foam.

2 Comments

  1. Tom Freeman

    Mike – as always, your workmanship is impeccable. I am not familiar with the Delta controller. Does the unit come with a transducer? If so, where did you mount it? Keep up the great work!

    Reply
  2. Michael H Yount

    Hey Tom – the controller ( http://www.dccontrol.com/constant_temperature_controllers.htm ) is the device pictured above. That’s all there is to it — it’s a digital pulse width modulated variable speed controller. Only requires 12V+, a ground and the temperature sensor (embed in radiator fins) connection. Couldn’t be any simpler. There’s an A/C connection to operate the fan when the compressor clutch is engaged. And a connection that allows you to use a volt meter to set the temperature set-point. No separate transducer.

    Reply

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