lsejlowe
Active member
For those who are interested in the additional space and slight HP increase of an electric fan setup, but aren't too keen on spending $400, this is what you're looking for. The two speed electric fan from the 1994 to 1998 Ford Taurus or Mercury Sable with the 3.8L engine are readily available at most junkyards for around $25 or less. I got mine for $20 so the guy wouldn't have to make any change :lol:
It's a 16" diameter fan and I've seen a variety of CFM ratings. The general consensus is that on low speed it pulls about 2000 CFM and on high upwards of 3500 CFM :amazed: Not too shabby for a junkyard fan. It's easy to see why this is such a popular conversion on lots of other cars from offroad rigs to hotrods. I'm surprised I've never seen one on a 'vette before. However, it can be a power hog on the high speed. Again, drawing on internet research the fans are said to draw up to 90 amps on startup of the high speed and up to a continuous 33 amps. A bit much for 10 gage wire and a 30 amp fuse, but you should be able to rely on the low speed and use the high speed only for extreme cases. Unfortunately I don't have an ammeter much less an oscilloscope to confirm or deny any of those numbers.
I mounted the fan to a 31" Tru-Kool radiator that I did an install thread about a year ago: cheap cooling sytem upgrade thread
I got some 1/8" by 1" aluminum and some 1/4" bolts and washers from Ace hardware. I bent the aluminum to make 4 brackets that wrap around the top and bottom flanges of the radiator and bolt to the fan shroud. Here's the fan with the brackets mounted up:
I also cut 4 slots in the shroud to get a wrench on the nyloc nut on the inside of the shroud. This makes installing/removing the fan from the radiator much easier.
So you've got the fan mounted to the radiator, now how do you make it all work? I wired mine up to use two temp switches. I put a 195* temp switch up by the radiator inlet and a 185* temp switch by the radiator exit. The 185* switch controls the low speed of the fan, the 195* switch controls the high speed. In theory, the low speed switch should kick in before the high speed switch because the water coming past the thermostat shouldn't be too much higher than 180*. Once the low speed fan has turned on it should be able to maintain enough cooling for normal conditions. The 195* high speed should be only for extreme cases. Here's the wiring diagram for such a setup:
However, after a little testing (more on that later) I've found that I'm better off just running the low speed fan. The fan runs less and still provides plenty of airflow through that big alum radiator. Here's a simplified diagram for just one switch:
Don't forget to run a ground wire from the radiator to the frame. The temp switches ground through the threads, so don't use any sealant or teflon tape on there.
I got the wire and SPST from Radio Shack and the SPDT relay and most of the crimp terminals from Autozone. If I were to do it all again I'd get actual Bosch relays online since they're pretty reasonably priced.
Initial Reaction/Evaluation:
The 195* switch needs to be at least a 205*. It would come on all the time and run way too long after the engine is shut off. Oddly enough, it would run for maybe 30 seconds after killing the engine and then shut off. But within a few minutes it would come back on and then run for 10 to 15 minutes. At this point I just disconnected the wire going to that switch and am very happy using only the lower switch. I duct taped my multimeter to the windshield and could watch it kick on and off as I drove around the neighborhood and it stayed off most of the time I was over 55 mph.
After testing the fan for a few days it was obvious that my original alternator was not up to the task. It was getting very hot very quickly. Turns out it was only a 42 amp alternator that came on cars without A/C. I swapped it for a 100 amp Powermaster unit and have been fine since.
I did not notice any major performance increase. It's tough to compare to 3 weeks ago when I drove it last, but I'd definitely say a clutch fan in good working order is not sucking that much HP. Don't expect to see 15 HP on the dyno because you switched to an electric fan. Guys making that claim had something else wrong with their system.
All in all I'm very pleased. It cools like a champ and opens up a LOT of room in front of the engine. Also gets that finger chopper out of the way.
It's a 16" diameter fan and I've seen a variety of CFM ratings. The general consensus is that on low speed it pulls about 2000 CFM and on high upwards of 3500 CFM :amazed: Not too shabby for a junkyard fan. It's easy to see why this is such a popular conversion on lots of other cars from offroad rigs to hotrods. I'm surprised I've never seen one on a 'vette before. However, it can be a power hog on the high speed. Again, drawing on internet research the fans are said to draw up to 90 amps on startup of the high speed and up to a continuous 33 amps. A bit much for 10 gage wire and a 30 amp fuse, but you should be able to rely on the low speed and use the high speed only for extreme cases. Unfortunately I don't have an ammeter much less an oscilloscope to confirm or deny any of those numbers.
I mounted the fan to a 31" Tru-Kool radiator that I did an install thread about a year ago: cheap cooling sytem upgrade thread
I got some 1/8" by 1" aluminum and some 1/4" bolts and washers from Ace hardware. I bent the aluminum to make 4 brackets that wrap around the top and bottom flanges of the radiator and bolt to the fan shroud. Here's the fan with the brackets mounted up:
I also cut 4 slots in the shroud to get a wrench on the nyloc nut on the inside of the shroud. This makes installing/removing the fan from the radiator much easier.
So you've got the fan mounted to the radiator, now how do you make it all work? I wired mine up to use two temp switches. I put a 195* temp switch up by the radiator inlet and a 185* temp switch by the radiator exit. The 185* switch controls the low speed of the fan, the 195* switch controls the high speed. In theory, the low speed switch should kick in before the high speed switch because the water coming past the thermostat shouldn't be too much higher than 180*. Once the low speed fan has turned on it should be able to maintain enough cooling for normal conditions. The 195* high speed should be only for extreme cases. Here's the wiring diagram for such a setup:
However, after a little testing (more on that later) I've found that I'm better off just running the low speed fan. The fan runs less and still provides plenty of airflow through that big alum radiator. Here's a simplified diagram for just one switch:
Don't forget to run a ground wire from the radiator to the frame. The temp switches ground through the threads, so don't use any sealant or teflon tape on there.
I got the wire and SPST from Radio Shack and the SPDT relay and most of the crimp terminals from Autozone. If I were to do it all again I'd get actual Bosch relays online since they're pretty reasonably priced.
Initial Reaction/Evaluation:
The 195* switch needs to be at least a 205*. It would come on all the time and run way too long after the engine is shut off. Oddly enough, it would run for maybe 30 seconds after killing the engine and then shut off. But within a few minutes it would come back on and then run for 10 to 15 minutes. At this point I just disconnected the wire going to that switch and am very happy using only the lower switch. I duct taped my multimeter to the windshield and could watch it kick on and off as I drove around the neighborhood and it stayed off most of the time I was over 55 mph.
After testing the fan for a few days it was obvious that my original alternator was not up to the task. It was getting very hot very quickly. Turns out it was only a 42 amp alternator that came on cars without A/C. I swapped it for a 100 amp Powermaster unit and have been fine since.
I did not notice any major performance increase. It's tough to compare to 3 weeks ago when I drove it last, but I'd definitely say a clutch fan in good working order is not sucking that much HP. Don't expect to see 15 HP on the dyno because you switched to an electric fan. Guys making that claim had something else wrong with their system.
All in all I'm very pleased. It cools like a champ and opens up a LOT of room in front of the engine. Also gets that finger chopper out of the way.
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hone: are you planning on going to Vette week in Eureka springs next month :beer: let me know i am planning on going i reserved a room when i was there last year :idea:
:hunter:
