Post by shifter502 on Jan 21, 2011 16:42:35 GMT -6
Sup Homies! Some of you have cooling issues with your ride. This could be do to an engine swap or engine upgrades that cause the engine to run hotter. In any case, the mechanical fan most older cars came with is not enough to keep your ride from over heating, especially if you idle a lot or cruise slow. An electric fan upgrade is the way to go and its not as expensive as you might think.
I resently installed an electric fan on my dads 83 Jeep CJ7. It has a small block Chevy engine with a 700R4 tranny and an NP208 Transfer case. Its one hell of a trail rig, but it has cooling issues. In the pictures you can see that it has a 6 blade fixed fan. These fans are not the best for cooling as they turn to slow at idle and at highway speeds it never stops turning so it causes the engine to use more fuel hurting fuel economy. The radiator shroud on this Jeep is really nothing more than a fan guard and it doesn't help channel the air through the radiator. By swaping out the fan I will improve highway MPG's and help insure the engine stays cool while climbing the trail.
First I started by removing the fan shroud. It was held in with just a couple of bolts. Yours maybe a little different so refer to your manual for its removeal. Next I loosen the bolts holding the fan to the water pump. Do not remove them at this time. Next I removed the serpintine drive belt. This engine is caburated and I'll cover how to do a serpintine drive conversion on the cheap in a later tread. Next I finish removing the bolts holding the fan to the water pump and removed the fan, the fan spacer, and the water pump pulley. You may need to replace the bolts that hold the pulley to the water pump with shorter ones. I used 1 and 1/4 inch long grade 8 hex bolts and lock washers. These are just long enough to bolt the pulley to the water pump. Before I installed the pulley back to the water pump, I ran a tread tap through the bolt holes on the water pump. This cleans up any burrs, insures your new bolts go in clean, and helps make sure when you torque down the bolts its accurate. I also used red Loctite tread locker and torqued the bolts down first to 15 ft lbs then 25 ft lbs. Now you can reinstall the serpintine drive belt.
At this point you should be able to see just how much room you have between the front of the engine and the radiator. This is important to know cause there needs to be room for the electric fan to be mounted and operate. I chose a fan with a shallow mounting depth cause the SBC is so big and didnt leave much room. Also you need to check the CFM rating on the fan and amperage draw. CFM stands for cubic feet per minute. The higher this number the more air it moves over the radiator fins. Amperage draw or amp draw is the measure of how much juice it takes to perform at the rated CFM level. A fan that has a 1800 CFM rating at 25 amp draw is less efficiant than a fan with 1700 CFM rating at 10 amp draw. Also pick a fan that is just under the same size as the radiator. My radiator on the Jeep was about 18in by 18in so I picked a single 10 blade 16in fan with a 2100 CFM ratine at 10 amp draw. There are all kinds of electric fans so take your time and pick the one thats right for your ride.
To install the fan I first had to modify the electric plug on the fan. I changed the plug to a 2 wire quick disconnect plug that I bought from the auto parts store's trailer wiring section. I did this for 2 reasons. First is I am mounting the fan directly to the radiator core and if I need to service the radiator I wont have to cut the wires to the fan. Second I didn't have the female plug that would fit the male plug on the fan. The wires were cut, soldered and I used heat shrink to cover the wires for a factory look on the fan side and did the same for the fan control harness side. Next find and mark the vertical and horizontal centers on the radiator core. This will help center the fan. Supplied in the fan kit comes the core through fan ties. These install by passing them between the fins of the radiator. They are held in place on the oppisite side by a locking square. They work kind of like zip ties. Besure to install the supplied rubber pads between the fan and the core and the core and the locking squares. This cushins the fan from damage caused by shock and vibration. Remember dont over tighten the straps or you could bend the radiator fins. Trim the excess fan ties on the front side of the radiator.
Now that the mechanical fan has been removed and the new electric fan physically installed the task of wiring the fan control comes next. I bought the fan and the fan control harness both from Summit Racing for about 140 bucks, shipping was free and I got them in 3 days.
In the kit comes everything you'll need to power the fan and for it to turn on and off automatically. I did also install the optional over ride switch so I could turn it on when im rock crawling. That switch doesn't come with the kit so I used an L.E.D. lighted switch.
Here is the wiring diagram to install the kit.
First I selected a place to install the thermal switch. There are many ports on a SBC to install it into but since my thermostat housing has accesory port the same tread size as the thermal switch thats where I put it. Use plenty of tread tape to make sure there are no leaks. I dont have any pics of the finished wiring but as long as you follow the diagram, solder and heat shrink, and cover the wires with wire loom it should work fine.
Once everything was installed I started the motor and watched the temp gauge. The kit I bought turns the fan on at about 185 degrees and turns off at about 170. The thermostat I am using is a 160 degre thermostat. If your running a 180 degre thermostat you'll need to change it to 160 other wise once the fan cools the fluid to below 180 the thermostat will begin to close bringing the engine temp back to above 180 degres. This setup will not allow the engine temp to be below 170 and will not let the fan shut off. After two good on/off cycles I hit the road.
On the road the engine feels way lighter and the fuel economy improved. These added fuel savings will in the long run pay for the upgrade. An added plus is the Jeep is a little quieter without that fan turning. I can now sit and idle in traffic and not worry about the Jeep over heating. Not having a mechanical fan to turn also frees up some ponys.
Hope this helps you guys convert from mechanical to electric fans and see that its a cost effective way to cool your ride.
I resently installed an electric fan on my dads 83 Jeep CJ7. It has a small block Chevy engine with a 700R4 tranny and an NP208 Transfer case. Its one hell of a trail rig, but it has cooling issues. In the pictures you can see that it has a 6 blade fixed fan. These fans are not the best for cooling as they turn to slow at idle and at highway speeds it never stops turning so it causes the engine to use more fuel hurting fuel economy. The radiator shroud on this Jeep is really nothing more than a fan guard and it doesn't help channel the air through the radiator. By swaping out the fan I will improve highway MPG's and help insure the engine stays cool while climbing the trail.
First I started by removing the fan shroud. It was held in with just a couple of bolts. Yours maybe a little different so refer to your manual for its removeal. Next I loosen the bolts holding the fan to the water pump. Do not remove them at this time. Next I removed the serpintine drive belt. This engine is caburated and I'll cover how to do a serpintine drive conversion on the cheap in a later tread. Next I finish removing the bolts holding the fan to the water pump and removed the fan, the fan spacer, and the water pump pulley. You may need to replace the bolts that hold the pulley to the water pump with shorter ones. I used 1 and 1/4 inch long grade 8 hex bolts and lock washers. These are just long enough to bolt the pulley to the water pump. Before I installed the pulley back to the water pump, I ran a tread tap through the bolt holes on the water pump. This cleans up any burrs, insures your new bolts go in clean, and helps make sure when you torque down the bolts its accurate. I also used red Loctite tread locker and torqued the bolts down first to 15 ft lbs then 25 ft lbs. Now you can reinstall the serpintine drive belt.
At this point you should be able to see just how much room you have between the front of the engine and the radiator. This is important to know cause there needs to be room for the electric fan to be mounted and operate. I chose a fan with a shallow mounting depth cause the SBC is so big and didnt leave much room. Also you need to check the CFM rating on the fan and amperage draw. CFM stands for cubic feet per minute. The higher this number the more air it moves over the radiator fins. Amperage draw or amp draw is the measure of how much juice it takes to perform at the rated CFM level. A fan that has a 1800 CFM rating at 25 amp draw is less efficiant than a fan with 1700 CFM rating at 10 amp draw. Also pick a fan that is just under the same size as the radiator. My radiator on the Jeep was about 18in by 18in so I picked a single 10 blade 16in fan with a 2100 CFM ratine at 10 amp draw. There are all kinds of electric fans so take your time and pick the one thats right for your ride.
To install the fan I first had to modify the electric plug on the fan. I changed the plug to a 2 wire quick disconnect plug that I bought from the auto parts store's trailer wiring section. I did this for 2 reasons. First is I am mounting the fan directly to the radiator core and if I need to service the radiator I wont have to cut the wires to the fan. Second I didn't have the female plug that would fit the male plug on the fan. The wires were cut, soldered and I used heat shrink to cover the wires for a factory look on the fan side and did the same for the fan control harness side. Next find and mark the vertical and horizontal centers on the radiator core. This will help center the fan. Supplied in the fan kit comes the core through fan ties. These install by passing them between the fins of the radiator. They are held in place on the oppisite side by a locking square. They work kind of like zip ties. Besure to install the supplied rubber pads between the fan and the core and the core and the locking squares. This cushins the fan from damage caused by shock and vibration. Remember dont over tighten the straps or you could bend the radiator fins. Trim the excess fan ties on the front side of the radiator.
Now that the mechanical fan has been removed and the new electric fan physically installed the task of wiring the fan control comes next. I bought the fan and the fan control harness both from Summit Racing for about 140 bucks, shipping was free and I got them in 3 days.
In the kit comes everything you'll need to power the fan and for it to turn on and off automatically. I did also install the optional over ride switch so I could turn it on when im rock crawling. That switch doesn't come with the kit so I used an L.E.D. lighted switch.
Here is the wiring diagram to install the kit.
First I selected a place to install the thermal switch. There are many ports on a SBC to install it into but since my thermostat housing has accesory port the same tread size as the thermal switch thats where I put it. Use plenty of tread tape to make sure there are no leaks. I dont have any pics of the finished wiring but as long as you follow the diagram, solder and heat shrink, and cover the wires with wire loom it should work fine.
Once everything was installed I started the motor and watched the temp gauge. The kit I bought turns the fan on at about 185 degrees and turns off at about 170. The thermostat I am using is a 160 degre thermostat. If your running a 180 degre thermostat you'll need to change it to 160 other wise once the fan cools the fluid to below 180 the thermostat will begin to close bringing the engine temp back to above 180 degres. This setup will not allow the engine temp to be below 170 and will not let the fan shut off. After two good on/off cycles I hit the road.
On the road the engine feels way lighter and the fuel economy improved. These added fuel savings will in the long run pay for the upgrade. An added plus is the Jeep is a little quieter without that fan turning. I can now sit and idle in traffic and not worry about the Jeep over heating. Not having a mechanical fan to turn also frees up some ponys.
Hope this helps you guys convert from mechanical to electric fans and see that its a cost effective way to cool your ride.