Kubota tractor overheating when fan replaced to electric. (Kubota G1900S (D722))

[GreensvilleJay]

1) 180 watts ,according to the fan datasheet off the web... (30 more than the dynamo can supply...)

2) doesn't really matter (air flow based on pitch(angle of attack) + fan speed (RPM) to get airflow(CFM)

3) he's using the duct/shroud..should be similar airflow( though pictures before /after would help...)

4) optical tach would be useful,though speed can be determined on mfr's chart of RPM vs voltage(if they supply it...)

5) be interesting to KNOW what CFM the stock fan DOES produce.... 802 FM might not be enough ??

Since the electric fan IS deigned as a 'rad fan' it 'should' work, again picture would help.
It might be that fan is designed to be 'in a duct' NOT 'just at the end'.... Some fans ARE designed that the mid pitch of the blades IS supposed to be 1/2 way between 'in' and 'out'...

 

[GeoHorn]

What load of equine excrement!

The OEM fan draws an adequate amount of air thru the radiator to get rid of any anticipated heat…. The “regulator” of rate of dissipation is the THERMOSTAT…. not the speed of air-flow.

Quit screwing with an “assumed” prediction of how much heat you predict necessary to remove… if you plan to increase engine work-load…wait until you find increased dissipation is necessary before you start resolving problems which don’t exist.

 

[lugbolt]

you need cfm not speed

the factory fan pulls x cfm (whatever it is) and is designed specifically for the application

the stock radiator is a copper/brass/lead core and is not all that efficient but with the factory fan and at it's rated speed in the correct shroud (which is of utmost importance in itself), it works, it's reliable.

Without knowing the CFM of each fan there's no telling what kind of can of worms is opened.

the shroud, as said, is every bit as important if not moreso than the actual fan itself. If air is allowed to be pulled around the fan and back onto itself, sure it moves air and maybe more air than the stocker, but may not be pulling it over the radiator core-where the heat is rejected, and where the work is done.

In all my years of fiddling with cooling systems I've never once seen an electric cooling fan that will move as much air as a belt driven mechanical fan. You can be fooled by the e-fan's ability to move air but if you actually measure the cfm, the large majority of the time the mechanical fans move more air. The big reason for e-fans on cars is that new style radiators are much more efficient in heat rejection so they can get away with less airflow. With that, an electric fan doesn't draw as much parasitic loss from the engine thus allowing them to improve emissions and MPG. If they could improve emissions and MPG with a clutch fan, you bet they'd do it as it's much simpler and less expensive to use that than the E-fan setup (wiring, relays, controls, the actual fan, etc)

 

[Chanceywd]

Kepner-Tregoe's Problem Solving & Decision Making .

I took this course in my work and the best part of it in problem solving was, What was recently changed? You took off the mechanical fan and replaced it with an electric one that wasn't designed for the application. In addition there is a domino effect to overload the charging system as others have stated here and that is going to lead to a dead battery. This is only going to lead to lead to unreliable function of the unit and or a short hour life. I hope it isn't under warranty during this experiment.

 

[lmichael]

The other reason modern cars need electric fans is the stupid transverse engine design we've been stuck with for so many years. It ain't right. Engines should face front to back and drive rear wheels

 

[pigdoc]

I had the same thought as ve9aa.

Stupid question: Is the electric fan spinning in the same direction as the belt-driven one was?

I'm on my second G1800, as of August. 1200 total hours on it. This one cools VERY nicely. Under full load and high RPM, it runs right in the middle of the temperature gauge range. When I unload it and throttle down, the temperature falls to the lower end of the gauge range within a minute or two.

The last G1800 I operated, I did not own. So, I had little control over its maintenance. It always ran hot. I typically pulled the screens from around the radiator a couple times every mowing season to clean them. And, blew the radiator fins out with a garden hose. That would help marginally, but did not completely solve the problem. I never quite figured out what the cause was...

I guess my point is that a properly functioning stock cooling system is up to the "stock" task.

Now, as you consider your power upgrades, PLEASE go through lugbolt's old postings until you find the ones on putting turbos on these little diesels. That is, before you start modifying. I think the biggest caution is that the combustion chamber is designed for normal aspiration, not boosted aspiration. So the marginal return in power to be expected by boosting is minimal.

And, you're right to be worried about cooling when you increase boost. A lot of boost (say, 50PSI - no kidding!) quickly provides piston-melting heat! Don't ask me how I know...

-Paul

 

[hagrid]

Wave a palm frond in front of the radiator.

 

[jacoBiceps]

This is another of the 'we need pictures' posts...
It could be that too much air is being moved which sounds 'wrong' but depending on HOW and WHERE the air flow happens ,can be why it's not working as expected.

 

[jacoBiceps]

1) 180 watts ,according to the fan datasheet off the web... (30 more than the dynamo can supply...)

2) doesn't really matter (air flow based on pitch(angle of attack) + fan speed (RPM) to get airflow(CFM)

3) he's using the duct/shroud..should be similar airflow( though pictures before /after would help...)

4) optical tach would be useful,though speed can be determined on mfr's chart of RPM vs voltage(if they supply it...)

5) be interesting to KNOW what CFM the stock fan DOES produce.... 802 FM might not be enough ??

Since the electric fan IS deigned as a 'rad fan' it 'should' work, again picture would help.
It might be that fan is designed to be 'in a duct' NOT 'just at the end'.... Some fans ARE designed that the mid pitch of the blades IS supposed to be 1/2 way between 'in' and 'out'...

 

[jacoBiceps]

Pictures

 

[jacoBiceps]

I had the same thought as ve9aa.

Stupid question: Is the electric fan spinning in the same direction as the belt-driven one was?

I'm on my second G1800, as of August. 1200 total hours on it. This one cools VERY nicely. Under full load and high RPM, it runs right in the middle of the temperature gauge range. When I unload it and throttle down, the temperature falls to the lower end of the gauge range within a minute or two.

The last G1800 I operated, I did not own. So, I had little control over its maintenance. It always ran hot. I typically pulled the screens from around the radiator a couple times every mowing season to clean them. And, blew the radiator fins out with a garden hose. That would help marginally, but did not completely solve the problem. I never quite figured out what the cause was...

I guess my point is that a properly functioning stock cooling system is up to the "stock" task.

Now, as you consider your power upgrades, PLEASE go through lugbolt's old postings until you find the ones on putting turbos on these little diesels. That is, before you start modifying. I think the biggest caution is that the combustion chamber is designed for normal aspiration, not boosted aspiration. So the marginal return in power to be expected by boosting is minimal.

And, you're right to be worried about cooling when you increase boost. A lot of boost (say, 50PSI - no kidding!) quickly provides piston-melting heat! Don't ask me how I know...

-Paul

I'm not looking to make huge power with this engine. I honestly might just keep the turbo vented to atmosphere just for the noises.

 

[jacoBiceps]

Kepner-Tregoe's Problem Solving & Decision Making .

I took this course in my work and the best part of it in problem solving was, What was recently changed? You took off the mechanical fan and replaced it with an electric one that wasn't designed for the application. In addition there is a domino effect to overload the charging system as others have stated here and that is going to lead to a dead battery. This is only going to lead to lead to unreliable function of the unit and or a short hour life. I hope it isn't under warranty during this experiment.

This tractor was made in 1996 and it has 1700 hours. I bought it used about 3 years ago. I'm probably gonna just go back to the belt drive.

 

[DaveFromMi]

Just curious as to how you are controlling the fan. Does it get progressively faster as coolant temps go up?

 

[jacoBiceps]

Just curious as to how you are controlling the fan. Does it get progressively faster as coolant temps go up?

No it doesn't. I have to manually turn it on and off. Right now, I just have it on all the time at low power. I have it hooked up to a PWM fan speed controller.

 

[Vigo]

Fans do most of their work at the outer edges of the blades because that is where it’s moving the fastest. A substantial part of the outer portion of your fan blades is obstructed by the shroud being bent over it. Try fixing that and see what happens.

 

[lugbolt]

might just keep the turbo vented to atmosphere just for the noises.

which can lead to overspeeding of the turbocharger. That could be an issue and it also depends on which unit you're using and what it's maximum rpm is.

after going back to look at the pics no wonder it's overheating. I think I recognize that fan. The air coming off of it moves pretty quickly but the actual CFM volume is lower than you'd think. I want to say 840 cfm which is nothing in terms of a cooling fan.

 

[lmichael]

which can lead to overspeeding of the turbocharger. That could be an issue and it also depends on which unit you're using and what it's maximum rpm is.

after going back to look at the pics no wonder it's overheating. I think I recognize that fan. The air coming off of it moves pretty quickly but the actual CFM volume is lower than you'd think. I want to say 840 cfm which is nothing in terms of a cooling fan.

Plus I believe that fan might be moving the air the wrong way as well. IIRC that design fan is deigned to "blow" through the rad on a vehicle with longitudinal engine layout. So mounted where it is, it's likely trying to "push" air through the rad.

 

[lugbolt]

Plus I believe that fan might be moving the air the wrong way as well. IIRC that design fan is deigned to "blow" through the rad on a vehicle with longitudinal engine layout. So mounted where it is, it's likely trying to "push" air through the rad.

normally you can pull the blade off, flip it, and then reverse the polarity of the leads. That will "usually" change it from a puller to a pusher, or vise versa. But yeah I can see where you're coming from.

 

[GeoHorn]

The other reason modern cars need electric fans is the stupid transverse engine design we've been stuck with for so many years. It ain't right. Engines should face front to back and drive rear wheels

or a “V-drive” such as found in boats.

 

[jacoBiceps]

Plus I believe that fan might be moving the air the wrong way as well. IIRC that design fan is deigned to "blow" through the rad on a vehicle with longitudinal engine layout. So mounted where it is, it's likely trying to "push" air through the rad.

It's a "puller" fan meant to pull air through a radiator.