Just Be Cool… Be Cool man!
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.