Location for 3/8 brushless fan water temp sensor

[Alponcho]

I'm installing Spal brushless fans and trying to decide where to put the 3/8 npt sensor on engine (LQ4 based 408). The instructions say to use a port on the hot side of the cooling system. The M12-1.5 port is open on the back of the RH head, and I have an adaptor I can use in this port from ICT Billet, however, the tip of the sensor sits within the adaptor rather than being directly exposed to the water jacket. Will this be a problem?

A second issue with this location is that the sensor wire ends up being pretty close to the plug wire.

A second option is to use the big coolant drain plug above the oil filter. ICT Billet has an M28 adaptor for this, and I have plenty of room there, however, from my understanding, this isn't the hot side of the engine. How much cooler is the water in this area relative to the heads?

Other alternatives I'm considering include a thermostat spacer with 3/8 bung, or a radiator hose coupler. Not skilled enough to install a bung in the aluminum radiator.

Looking for thoughts and suggestions about what would work best.

[dontlifttoshift]

Use the ECU to control the fans?

Bung in radiator or upper hose would be my second choice in this application.

[srode]

You need to measure the engine coolant not the radiator because the engine temperature is what you care about. You don't care what temperature the radiator is, it will always be cooler than the engine. How much cooler than the engine depends on a lot of variables.

[dhutton]

You need to measure the engine coolant not the radiator because the engine temperature is what you care about. You don't care what temperature the radiator is, it will always be cooler than the engine. How much cooler than the engine depends on a lot of variables.

I hear what you’re saying Steve but if you install it that way the fan may be running when the thermostat is closed which really doesn’t accomplish much. Putting it on hot side of radiator might prevent that scenario. They sell temperature sender adaptors that install in the upper radiator hose.

Temperature controller needs to be mated with correct temperature thermostat. Obvious but quite often not done….

Don

[Vimes]

https://www.scramspeed.com/products/...witch-200.html

https://cimg8.ibsrv.net/gimg/ls1tech...f4ca2bdcbd.jpg

Same sender, correct thread, no adapter needed. All these switches do is expand internally to make a connection when the temp is hot enough. There is a port on each cylinder head for the factory temp sender, and one (usually passenger rear) is not used, use it for the fan control. And, I would use the 200 - that way the fan won't be trying to run all the time while on the highway. You will also want to set the fan up to run when the air conditioner comes on. The diagram above shows how to wire it up using a relay, and the way it's wired either the trinary switch or the thermostat switch will apply a ground to 86 on the fan relay.

If you want a superior temp controller and can't use the LS ECM, you want a Delta Current controller. If I don't have the option of using the ECU to run the fans, this is what I use. Probes the radiator, varies current to keep a set temp at all times, can handle a single or dual fans, Ford Taurus dual speed fan, can handle an electric water pump and can accept an input from the AC compressor to turn the fan on when necessary. The big plus for this controller is it will soft start the fans and will vary the speed from 1 percent to 100 percent in order to keep the coolant temperature right on the nose for its set temp rather than cycling the fans on and off to stay in a range.

http://dccontrol.com

[Alponcho]

https://www.scramspeed.com/products/...witch-200.html

https://cimg8.ibsrv.net/gimg/ls1tech...f4ca2bdcbd.jpg

Same sender, correct thread, no adapter needed. All these switches do is expand internally to make a connection when the temp is hot enough. There is a port on each cylinder head for the factory temp sender, and one (usually passenger rear) is not used, use it for the fan control. And, I would use the 200 - that way the fan won't be trying to run all the time while on the highway. You will also want to set the fan up to run when the air conditioner comes on. The diagram above shows how to wire it up using a relay, and the way it's wired either the trinary switch or the thermostat switch will apply a ground to 86 on the fan relay.

If you want a superior temp controller and can't use the LS ECM, you want a Delta Current controller. If I don't have the option of using the ECU to run the fans, this is what I use. Probes the radiator, varies current to keep a set temp at all times, can handle a single or dual fans, Ford Taurus dual speed fan, can handle an electric water pump and can accept an input from the AC compressor to turn the fan on when necessary. The big plus for this controller is it will soft start the fans and will vary the speed from 1 percent to 100 percent in order to keep the coolant temperature right on the nose for its set temp rather than cycling the fans on and off to stay in a range.

http://dccontrol.com

Vimes, are you saying that this switch can be used to control the pwm function on SPAL's brushless fans.

Also, the brushless SPAL fans have their own built in PWM controller, so no need for an external PWM controller (though I do have a new unit from DCC on a shelf that I plan to use on a different project).

[srode]

Don, if the fans are running when the thermostat is closed then the thermostat is opening too hot. For it to make sense to me, the sensor that turns on the fans should always trigger at a temperature higher than the thermostat.

Having it in the thermostat housing or at least on the hot side of the radiator might be ok, would just need little bit different trigger point for the worst case scenario. But I think if I had turned in a design like that in my controls class my grade might have taken a serious hit.

[dhutton]

Vimes, are you saying that this switch can be used to control the pwm function on SPAL's brushless fans.

Also, the brushless SPAL fans have their own built in PWM controller, so no need for an external PWM controller (though I do have a new unit from DCC on a shelf that I plan to use on a different project).

No it cannot. Use the Spal controller.

don

[dhutton]

https://www.scramspeed.com/products/...witch-200.html

https://cimg8.ibsrv.net/gimg/ls1tech...f4ca2bdcbd.jpg

Same sender, correct thread, no adapter needed. All these switches do is expand internally to make a connection when the temp is hot enough. There is a port on each cylinder head for the factory temp sender, and one (usually passenger rear) is not used, use it for the fan control. And, I would use the 200 - that way the fan won't be trying to run all the time while on the highway. You will also want to set the fan up to run when the air conditioner comes on. The diagram above shows how to wire it up using a relay, and the way it's wired either the trinary switch or the thermostat switch will apply a ground to 86 on the fan relay.

If you want a superior temp controller and can't use the LS ECM, you want a Delta Current controller. If I don't have the option of using the ECU to run the fans, this is what I use. Probes the radiator, varies current to keep a set temp at all times, can handle a single or dual fans, Ford Taurus dual speed fan, can handle an electric water pump and can accept an input from the AC compressor to turn the fan on when necessary. The big plus for this controller is it will soft start the fans and will vary the speed from 1 percent to 100 percent in order to keep the coolant temperature right on the nose for its set temp rather than cycling the fans on and off to stay in a range.

http://dccontrol.com

The DCC controller works with brushed fans. The OP has a brushless fan. Huge difference. Same with the thermostat switch you posted, it does not work with brushless fans…

[dhutton]

I know Andrew has controlled Spal brushless fans with the Holley Terminator ECM if you want to go that route. Contact him if that appeals to you.

[Alponcho]

It would be nice to run it through the Terminator...one less sensor to worry about. I'll contact Andrew.

[Vimes]

The DCC controller works with brushed fans. The OP has a brushless fan. Huge difference. Same with the thermostat switch you posted, it does not work with brushless fans…

Sorry, just got back from vacation today. Admittedly, I used them with a brushed fan, specifically a pair of Permacool 19115s. But, per their site they work with all fans. From their site:

"The S50 can be used for all known aftermarket fans and all of the brushed OEM fans with the exception of the factory Ford F150 fans. The S70 has an increased current capability, allowing it to also power even the 63 Amp F150 fan"

It would be worth an email, if nothing else. However, if there is an onboard pwm module inside the fan, there's no reason to have two controllers.

Not really sure why the thermostat switch would matter as any thermostat is just a temp activated switch.

[dhutton]

Sorry, just got back from vacation today. Admittedly, I used them with a brushed fan, specifically a pair of Permacool 19115s. But, per their site they work with all fans. From their site:

"The S50 can be used for all known aftermarket fans and all of the brushed OEM fans with the exception of the factory Ford F150 fans. The S70 has an increased current capability, allowing it to also power even the 63 Amp F150 fan"

It would be worth an email, if nothing else. However, if there is an onboard pwm module inside the fan, there's no reason to have two controllers.

Not really sure why the thermostat switch would matter as any thermostat is just a temp activated switch.

Sorry but you are wrong on both counts.

Don

[dontlifttoshift]

To be fair, that is a direct quote from the DCC website. Maybe they have not updated in awhile.

____

As has been noted, the Spal fan in the OP already has a controller it just needs the signal from the supplied sending unit or the ECU for it to operate. Sounds like Alponcho has Holley TerminatorX and I would make the argument that controlling that fan with anything other than the ECU is wrong.

[Vimes]

Sorry but you are wrong on both counts.

Don

OK, you'll need to explain why I'm wrong on the temp switch. A fan requires a switch to turn on power, and turn off power. It does not matter whether the fan is brushed or brushless. The only difference I can see for a Spal fan with a built-in controller is if the Spal fan requires a variable resistance to tell it what the temp is, in which case any GM temp sender should do the trick.

I'm also leaning towards the DCC knowing whether or not their controller works on a brushed and a brushless fan, and am sending them an email to ask. I'll post their answer.

[marolf101x]

A brushed fan uses only power and ground, which go directly to the brushes and ground to make it spin.

A brushless fan has power and ground going to a PCB with a processor on it. It also has a "signal" wire going to the processor.
The processor uses the signal to turn on/off hardware to control how fast the fan spins.

The "signal" is not just ON or OFF. It's pwm (pulse width modulation). So the signal changes between +V and ground. The longer it stays at +V, the faster the fan spins (well, depending on what the software in the fan says to do. . .it could be opposite).

[dhutton]

OK, you'll need to explain why I'm wrong on the temp switch. A fan requires a switch to turn on power, and turn off power. It does not matter whether the fan is brushed or brushless. The only difference I can see for a Spal fan with a built-in controller is if the Spal fan requires a variable resistance to tell it what the temp is, in which case any GM temp sender should do the trick.

I'm also leaning towards the DCC knowing whether or not their controller works on a brushed and a brushless fan, and am sending them an email to ask. I'll post their answer.

Brushless fans require a low power control signal that has a variable duty cycle. Varying the duty cycle varies the speed of the fan. The duty cycle varies according to the sensed temperature. This pic illustrates the concept of variable duty cycle. DCC controllers do not generate this control signal for use with brushless fans. It is generated internally but not available to control brushless fans. Carl at vaporworx has developed a controller that generates the pwm signal for brushless fans if you would like to pursue it further. I’m sure he’d love to answer all your questions…

Don

[dhutton]

Here’s a Spal wiring diagram for brushless fans. The pwm control line is the white wire. The “sensor” is actually a controller that generates the PWM control signal.

Don

[dhutton]

Brushed fans use DC motors. Brushless fans use polyphase AC motors and their circuitry includes a DC to polyphase AC inverter. The speed is varied by varying the frequency of the polyphase AC voltage applied to the motor. These brushless fans are fairly complex compared to brushed fans. But no brushes means improved reliability and increased MTBF.

Don

[Vimes]

OK, that makes more sense.

In other news, still waiting on DCC Control to respond. Historically they aren't fast with the responses. The specific question asked:

"I was wondering if your S50/70 fan controllers can run a brushless fan as well as a brushed fan. Also, is it able to work with a Spal fan that has a built-in pwm controller?"

Although now I feel bad about hijacking the thread. Perhaps a moderator type can clean it up and make a new thread to finish this up.