10 replies to this topic

[Swarbs]

Looking at installing one of those kit thermo controlers

 

Running a PWR ali radiator SPAL single fan and it will be cooling a 355

 

Doing the research and looked at the Derale , SPAL and Davies Craig units 

 

Wondering what others are running and if there is anything out there 

 

Seen something that has a soft start (Derale but have seen some bad reports) which is a bloody good idea -- https://www.summitra...reviews?page=2   Check out the reviews

 

Any thoughts or input welcome

 

 

[rodomo]

Old Magnas had a thermal switch in the lower part of the radiator.

 

I thought this was a good idea as it meant the fan would keep running even if the water level was low?

 

Some fan switches that are mounted high will turn the fan off because they get too cold if the level is low.

 

I rebuilt the engine in my Rangie years ago and took the radiator and Magna switch along to the radiator bloke and asked him to fit it down the bottom of the tank.

 

Na na na mate, it needs to be up high blah blah blah.

 

Me: Ok (stoopidly)

 

The fan cycled too much, it should have been mounted lower.

Edited by rodomo, 24 March 2018 - 09:28 PM.

[Bigfella237]

The switch needs to be at the top of the radiator because that's where the hot coolant is immediately after leaving the engine, if you installed it in the outlet of the radiator you will be measuring coolant AFTER it's been cooled, meaning that by the time the fan cuts-in the engine temperature will already be too high.

 

That may not matter so much with an adjustable controller because you can "tune" it to suit, depending on the controller of course, some may not be able to be adjusted that low.

 

But a far better idea is to install the switch just under the thermostat (on the engine side), that way if the thermostat sticks shut for some reason at least you will know about it, if you're measuring temperature at the radiator (after the thermostat) but the thermostat never opens, your reading will never alert you until it's too late.

 

The problem with your fan(s) cycling too much is due to the hysteresis built-in to the thermal switch, some controllers allow you to set both "on" & "off" temps, some don't allow you to adjust the hysteresis at all, much like thermal switches.

 

It's been my experience that temp gauges actually go up (or "spike") when the coolant level drops below the sender as the air / steam is actually hotter than the coolant itself.

[axistr]

The switch needs to be at the top of the radiator because that's where the hot coolant is immediately after leaving the engine, if you installed it in the outlet of the radiator you will be measuring coolant AFTER it's been cooled, meaning that by the time the fan cuts-in the engine temperature will already be too high.

 

That may not matter so much with an adjustable controller because you can "tune" it to suit, depending on the controller of course, some may not be able to be adjusted that low.

 

But a far better idea is to install the switch just under the thermostat (on the engine side), that way if the thermostat sticks shut for some reason at least you will know about it, if you're measuring temperature at the radiator (after the thermostat) but the thermostat never opens, your reading will never alert you until it's too late.

 

The problem with your fan(s) cycling too much is due to the hysteresis built-in to the thermal switch, some controllers allow you to set both "on" & "off" temps, some don't allow you to adjust the hysteresis at all, much like thermal switches.

 

It's been my experience that temp gauges actually go up (or "spike") when the coolant level drops below the sender as the air / steam is actually hotter than the coolant itself.

 

I can see your theory there bigfeller but if the thermostat sticks no use running the fans because there wouldn't be any coolant flow in the radiator. I also use a Magna fan controller sensor in the hatch. its mounted in the top tank just above the core and next to the top radiator hose. The Magna sensor is adjustable by means of a very small screw. I have never had any overheating issues even on 45 degrees days with the A/C going. I decided to fit a override switch on the console but haven't needed to use it yet. When ever the A/C compressor cuts in I wired it to trigger the fans. The override switch has a LED in the centre and every time the fans cut in it illuminated weather its in auto or override mode so I can see at a glance their operating. Very fool proof. I was going to control the fans with the computer when I fitted the EFI but it works so well I just left it as is.   

[Swarbs]

Some good reading and thanks 

in the perfect world and i suppose what i am trying to achieve is a controler that will regulate the fan speed to keep the engine temp at a constant

Not just kick in and out with the fans going flat out 

 

Say for instance you have an ideal temp preset of 190 degreesF and you can preset a cut in at 50% fan speed at 180 that will ramp up to 75% at the preset 190 and by 195 degrees it will be at 100% trying to bring it back to the preset of 190 -- you tell it where you want to be

 

 

Have to be good for the engine remaining at a constant temp -  fans are not running flat out chewing power - they start soft so it must prolong its life and will be a damn site quieter 

SPAL were playing with a thing called pulse wave modulation which was built into a controler which pretty well achieved this but i think it still only had off and on   

 

The sender would need to be able to sense the temp not just switch off and on and this would tell the controler what the fan needs to be doing 

 

The way i see it it must be achievable just need to find the right stuff

 

 

Got a second port put into the radiator when i got it made below the temp switch for a low water sender so if it does drop its water it will let me know or toying with fitting one of those engine saver alarm thingys

[axistr]

Its easy to control high and low speed electric fans when they are driven by a suitable engine computer. Most vehicles made in the last 20 years are controlled this way by the E.C.M.  If you have a second port in the radiator you could fit twin senders and have one operating on/off and the second sensor triggers the second fan at 200 deg F

 

There are a few truck manufacturers that have a combined sensor that trigger at a pre-set temp and sense low coolant all in one. However personally I would prefer both fans to kick in together cool things down quickly in traffic and cut back out. They are only effective at speeds below 45-50kph. In most vehicles there is only a temperature fluctuation of 4 or 5 degrees C and this would make no difference in the overall engines longevity or performance. Yes two fans draw more power but at the end of the day they would only need to operate for half of the time.  

 

I like having the tell tail light come on when the fans cut in because with the windows are up I can't hear my fans working. So I wouldn't be to concerned about noise. I am using duel S blade fans,  the original fan assembly is from a Fraud Falcon EL series. At the end of the day the fans are only going to run when the engine needs extra air flow over the radiator core for cooling. I always watch my temps and pressures when driving, a rise more than normal in temp tells you there is something going on. Don't know that an extra warning circuit is warranted unless your doing some sort of motorsport driving and are fixated on the track.

[Swarbs]

No computer Axistr so i can't tap in there anywhere -- running tractor style

I like your idea of the light on an over ride switch for when they are on 

 

As i said in the original post only have a single fan so i have a spare port in the radiator and would rather have some sort of back up protection in some shape or form

It is the fitter in me coming out 

 

Have found another with a brand name of Lingenfelter just have to do a bit more research on it - expensive but for what i have spent on the motor i see it as a small price to pay 

Just think there has got to be better way than just off and on with everything flat out  

[CI 0308]

I run the Davis Craig electronic controller with twin fans and it has been fine. It also has an override function that I use as well. It is fully adjustable with a sensor that goes in between the cores of the radiator. If stop starting in traffic I just hit the switch and they run continuously. I also have a discreetly mounted electronic temp gauge to keep an eye on the temp as the stock gauge is a bit on the average side.

[turbo76lx]

I'm running a Dakota Digital controller, Had no problems and easy enough to set up.

 

 http://www.dakotadig...prod/prd852.htm

 

[koalasprint]

https://www.ebay.com...i4AAOSwt7pXNNL0

I bought a handful of these. Cheap and effective.They switch my relays on and off.(Twin fans) I'm using two different temperature switches. No need to drill into the radiator. I stuck them on with JB weld. The hotter it gets the better it sticks.

Radiators are made to conduct heat. So heat transfer to the switches is effective. I put mine on the bottom radiator tank near the radiator water outlet. I want the fans to control the water temperature entering the engine. The thermostat can control the temperature coming out.

Maybe you can do similar by using the switches to control the fan speed.

You could also use a hotter temp switch for a warning light. If I did that I'd be tempted to put it on a cylinder head and/or the radiator. (In parallel if using two)

I hope that all makes sense.

Cheers, Steve.

Edited by koalasprint, 26 March 2018 - 02:05 PM.

[VZ1_60]

have a look at this site and instructions, note thermal switch is in the lower hose ............

 

www.foundry4x4.co.uk, and search X Eng instructions, X-Fan fitting instructions

 

cheers, john