by Salman SHAMI
This weekend I finally changed over to an electric fan in my Datsun 260Z. I used a thermo electric fan out of a Nissan Pulsar. which I bought from the wreckers for $50. This fan is designed to be fitted behind the radiator, i.e between the radiator and the engine. I wanted to install it ahead of the radiator to improve efficiency. Reversing the fan was simple. I took the nut of the front and simply pulled the fan off and fitted it reversed. Naturally I also reversed the polarity.
The fan came with a housing with three brackets welded to it. One on one side and two opposite to it. All those brackets had holes. I managed to align the hole in the single bracket with a pre-existing hole by enlarging the hole in the fan bracket. I bolted the fan using the single hole. For the opposite side I cut a thick aluminium strip 35.5 mm long. This I bolted vertically onto the car and bolted the other two brackets on to it. Naturally I had to first make holes in the aluminium strip and in the body. The fan was now fitted ahead of the radiator on the right hand side in front of the water intake. This I did to remove more heat because that is the hottest part of the radiator.(There is about 6 inches of radiator that are not covered by the fan.) Because I had no power tools this took me 2.5 hours.
The next day I resumed the job. First in line was the thermostat switch. This comprises a copper bulb and a capillary tube filled with some fluid which expands and activates a switch through a lever. The bulb is connected to the switch housing by the thin copper capillary tube. The thermostat kit comes complete with a tapered rubber ferrule with a groove in it so that the bulb can be inserted into the radiator hose and the capillary can pass through the groove in the ferrule. This helps to prevent leaks. BTW, the switch is similar to type used in fridges.First I removed the top radiator hose and inspected it. It was starting to look a bit dicey to me so I threw it out. Then I fixed the thermostat onto the inner mudguard and carefully bent thermostat's capillary tube to enable me to run it along the side of the radiator into the upper hose.
I applied some silicon paste to the water housing pipe and installed the new radiator hose on it and tightened the clamp. Then I did the same to the radiator pipes and stuck the rubber ferrule on to it. I passed the bulb and capillary tube into the hose and pressed the capillary tube into the groove on the ferrule. Then holding the ferrule with a screwdriver (because it was slipping and sliding around due the silicon paste) I slowly moved the hose onto the pipe. I had the adjust the capillary tube because it had moved a millimetre or so out of the groove in the ferrule but finally I got it right. I tightened the clamp with the clamp bolt 180 degrees away from the capillary and ferrule.
Electric connections came next.I connected the input of the thermostat switch with ignition. For this I took the current off the input to the resistor of the distributor circuit. The output of the thermostat went to one terminal of the switching circuit of a 40 Amp relay switch. The other terminal of the relay's switching circuit was connected to ground.
Then I connected one terminal of the relay's switched circuit to the battery (through a fuse) and connected the other terminal to the fan's positive terminal (formerly negative). The negative terminal of the fan was connected to ground.
After finishing I checked all bolts and connections and then started the car. I checked the working of the fan and then taped all the loose cables. Then I removed the original fan and adjusted the thermostat switch to only operate the fan slightly above normal operating temperature.
I topped up the radiator and went for a test drive. The car certainly warmed up quicker, was quieter. So much so that I started to hear a whistle from the mirror. I felt an increase in acceleration and an increased willingness to rev. Which is not surprising since the old fan weighed about 5 kg. Since it was a cool night the fan really only came on when the car was idling. Over all it kept the temperature constant. I have yet too drive it in summer and see how well it does in a traffic jam. If necessary I will then fit a second fan to either run in parallel or sequentially.
Total time taken:
A couple of months ago I installed an electric fan to replace the viscous one that was there. The fan I bought was a bit small.
I've always thought that it would be hard to beat the performance of a properly shrouded engine driven fan with an electric one. How do the temperatures you are getting now compare to those you were getting with the stock setup?
I "replaced" my viscous (solid!) driven fan with an electric 10" (or maybe 12"....) last year, just before another delightful high desert summer/southern californian commute season. (read: 100+F/38+C)
1.) I "lost" the turbine sound that was a result of driving the stock/viscous fan (design speed:1200-1500 RPM) at full engine speed
2.) I gained (what seemed like) about 10% more power lost to parasitic load from item 1 above.
The fan (made by Riall, or somebody like that) came with a temp sensor that had a 2 1/2 inch "probe" made of some fairly conductive material that was made to rest among the tubes, peacefully observing the the little thermals as they went by, and only cause the fan to spring into action once those little tubes became just a little too hot. Or something like that.
I epoxied the probe into the core (epoxy for add'l heat transfer integrity & add'l physical security....didn't want that little sucker to fall out.) I placed the probe directly adjacent to the lower (pick- up) pipe, on the rationale that I wanted the fan to run only after the whole radiator had heated up "too hot".
This has been a very sucessful installation. Given the desert conditions, and the frequent stop-and-go driving in very warm temps, the temp stays in the acceptable range. Even in the most despicable of traffic, I would estimate a duty cycle of 20%, and then only after a full period of "hot soak" caused by EXTENDED idling. One can hear the fan kick on, and actually watch the temp come down.
The fan itself was mounted to the AC condensor using the plastic "push nuts" that come with this general class of fan. I mounted it in a push configuration while the radiator was out for recoring. The orig fan and shroud were removed and saved ('cause, I JUST CAN'T THROW IT AWAY, that's why!)
I have found that the Z tends to do a very good job of flowing sufficient cooling air at speeds above about 30MPH/50KPH to keep the engine cool.....the fan never runs when I can sustain speeds above that, regardless of the traffic and conditions.
In attempting this install on a similiar car, I was unable to obtain the cool probe mentioned above, but instread got one of those funky thermostats that snake around the upper hose and have an adjustament for the set point. The pushnuts were the same....in fact I had some left over from the above install on my own car. I could not get the customer to pay for the radiator R&R, and discovered subsequently that the core was quite rotten.....by puncturing several GUSHERS in the radiator merely by pushing the pushnuts through the core. Combine this little observation (i.e., you need to have a decent rad to begin with!) and the fact that I could never get the seal around the hose/thermo probe to stop leaking, despite the fact that I even read and followed alll the directions.....leads me to suggest that all electric fans and kits are not created equal.....check it out before you buy. Look at the parts, and make sure you beleive that what they send you can in fact be installed in the manner described!