Anyone removed clutch fan and replaced with electric?

[SlickGT1]

Originally Posted by bcredliner

I have seen that removal method used. I think there is the possibility, however small, to damage the water pump so I would rather use a holding tool and I am under no time pressure.

No, don't go nuts. A solid rap on the wrench, and its off. The thread pitch on that nut is huge, and once you break off the nut loose, even a fraction of a turn , it is off. A box end across the fan bolts will hold the fan in place too.

[bcredliner]

Thanks, I may give that a try.

[bcredliner]

SAE is just a bit larger than 1 1/4in. wrench. There is a cars and coffee tomorrow so I will wait until after that to start on the fan.

[admranger]

32mm us the size of the fan clutch nut.

Please remember that it is left hand threaded.

[bcredliner]

Tried holding the pulley with screwdriver and whatever else I could find that might work. Either I couldn't get enough leverage or what I tried wouldn't work. Tried the whack the wrench method a few times still no luck. Ordered the proper wrench so it will be a few days more before I can install the fan.

Good thing I decided to do this as when I was trying to get the nut off I noticed one of the pulley bolts was about to fall out. I found another very loose and a third barely tight. Just dumb luck.

[TiAgX5]

Originally Posted by bcredliner

Tried holding the pulley with screwdriver and whatever else I could find that might work. Either I couldn't get enough leverage or what I tried wouldn't work. Tried the whack the wrench method a few times still no luck. Ordered the proper wrench so it will be a few days more before I can install the fan.

Good thing I decided to do this as when I was trying to get the nut off I noticed one of the pulley bolts was about to fall out. I found another very loose and a third barely tight. Just dumb luck.

Be sure to use proper torque spec and lock-tite on the pulley bolts.

The plastic pulley materal cracks when over-torqued!

[bcredliner]

The electric fan is installed.

The fan is a Flex-a-lite Trimline model 118. I have an adjustable Flex-a-lite thermostatic fan controller model 31148. These choices were after considerable research including multiple discussions with Flex-a-lite and Spal techs.

I chose the fan based on a CFM rating that was sufficient to cool a 500-600 hp big block. The fan has a low profile allowing me to continue to use the original fan shroud that houses the OE pusher fan sensors.

I chose to control the fan with an adjustable thermostat because that gives me the option to turn it completely off to free the most hp and for daily driving have the fan continue to cool when the key is off. The control is set to turn on the fan just prior to when the OE pusher fan is Thermostatically activated. Once I had the thermostat set on the new fan I let the engine idle until the fan cycled 4 times. It runs about under 2 minutes per cycle verifying the CFM is more than sufficient to cool the engine without the OE electric fan.

The install was not difficult but it took considerable time to think through the process. I could not find any DIY instructions so I mocked everything up before doing the final install. As I expected, even with the benefit of the mockup, it was necessary to make several changes along the way to improve the install.

While I waited for the proper clutch fan removal tool to arrive I tried the whack the 32mm wrench with a hammer method. May have been just my fan but if I hadn’t purchased the tool I would still be whacking it. The proper tool makesremoving the clutch fan a breeze.

Removing the shroud with the fan was easy. Just disconnect the sensors from the side of the shroud and the plastic connectors on top and pull the fan and shroud out together.

The shroud and the electric fan have to be dropped in together. That makes centering the fan to the shroud center cumbersome. I taped a dowel to the top of the water pump shaft and another to the center of the fan motor. Then I positioned the fan directly below the fan dowel on the shaft. It was easy to get the fan straight by lining it up with the horizontal supports for the fins. I hung it in place with two small punches that I pushed all the way through the radiator so I was sure the fins I was spreading were not blocked. I used the plastic hangers that came with the fan to secure it. The gap in the fins was just wide enough that the hangers treaded rather than slid through the fins. This became important because the location of the lower connectors was not visible from the front of the radiator so the plastic nuts could not be used. The top connectors were accessible so they are threaded and secured. The fan is very secure as is. The thermostat control is also in the radiator fins.

There is plenty of wire in the controller kit to do the install. There are no extra connectors. Once I had all the wiring done I was able to conceal the wires other than at the controller with plastic wire loom covering.


Initial observations:

The engine is significantly quieter when neither fan is running. An unusual engine noise will be much easier to hear and pinpoint the source.

The clutch fan is fairly heavy. I don’t think the load reduction on the water pump bearing without the clutch fan would be significant. Based on the weight of the clutch fan I think it is quite significant.

When the engine is up to operating temperature the fan starts up several times after the key is off since it is thermostatically controlled. I will have to see if that runs down the battery. It doesn’t run that long so I doubt that it will be a problem but it is worthwhile to mention.

The engine free revs noticeably faster.

I have not been out of the garage to see if I can tell if there is a difference in acceleration. Based on how the engine free revs and all tech info there will be an improvement. There are so many environmental and mechanical variables I am not going to declare success or failure on if it seems faster. This is something that one either believes research and the results of other applications or they don’t. I am very confident this mod is well worth the time and $$$$.

[TiAgX5]

Good to hear it worked as planned Brian.

[bcredliner]

Thanks James. There is still the test of time to go through. I will be watching the temp gauge much closer than normal for several weeks to be comfortable all is well. While I can't substantiate my opinion I think taking the load off the water pump bearing may be reason enough to make change.

[TiAgX5]

Originally Posted by trader4

I would submit that you really didn't take much load off the water pump bearing. The main force acting on that bearing is from the tension of the belt, not the weight of the fan. If you measured that force with or without the fan, it isn't going to make a big difference. The tension force is way larger. As for that being a reason to remove the fan, I don't think so. I've had long history with lots of cars that used mechanical fans and no early water pump issues. Belt driven arrangements like that are common and not a particular source of failure, provided decent bearings are used.

Granted the belt tension is the greater load.

Bearings perform better with a constant load, any out of balance condition in the fan ass'y will increase bearing wear.