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Cooling Fan Tech

Gonna do some looking...

The ideal coolant flow rate is one that will provide optimum coolant flow velocity through the radiator tubes in the range of 6 to 8 feet per second. Flow velocities above 10 feet per second should be avoided.
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Motor Coolant Flow Design for Engine Cooling

An article on Engine cooling mods with how to improvements to get better cooling for your motor with lower coolant temps and better heat control on the track
www.enginebasics.com
 
CarterKraft said:
Gonna do some looking...


Motor Coolant Flow Design for Engine Cooling

An article on Engine cooling mods with how to improvements to get better cooling for your motor with lower coolant temps and better heat control on the track
www.enginebasics.com
Click to expand...
A 1.25" I'd pipe at 35 gpm is a little over 9 gpm, so if that pump is actually capable of that flow then that would actually be too much flow.
 
Factory LS pumps move a LOT more than 35gpm
 
Bebop said:
Factory LS pumps move a LOT more than 35gpm
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Is that measured before or after the restriction of the thermostat?

Just because it pumps more into a bucket doesn't mean it's actually sending that much volume through the radiator.
 
arse_sidewards said:
Is that measured before or after the restriction of the thermostat?

Just because it pumps more into a bucket doesn't mean it's actually sending that much volume through the radiator.
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ugh ?

Water pumps are positive displacement pumps.

Flow is a factor of displacement and RPM.

If you have an electric WP, you are facing the exact same problem.
 
Bebop said:
ugh ?

Water pumps are positive displacement pumps.
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Automotive water pumps are absolutely not positive displacement.

The clearance between impeller and housing should be a dead giveaway as should the holes many of them have in the back side of the impeller from where they stamp and bend the fins as should the fact that system pressure doesn't go to the fucking moon and pop shit when you let the engine rev with the thermostat closed. :laughing:

Edit: Couldn't find an LS pump cutaway so this will have to do.

Edelbrock_water_pump_cutaway_300x300@2x.jpg
 
arse_sidewards said:
Automotive water pumps are absolutely not positive displacement.

The clearance between impeller and housing should be a dead giveaway as should the holes many of them have in the back side of the impeller from where they stamp and bend the fins as should the fact that system pressure doesn't go to the fucking moon and pop shit when you let the engine rev with the thermostat closed. :laughing:

Edit: Couldn't find an LS pump cutaway so this will have to do.
Click to expand...

You type faster than me. Yea, I’ve never seen an automotive water pump That was positive displacement. Positive displacement either pumps or stalls.
 
I was surprised the car pump is rated at 35-37 gpm, I don't know why but that seemed like a lot to me.

I shouldn't be surprised though really given the size of the hoses and passages.
 
Meziere electric HD pump is 55.
Stewart mechanical race pump is 140.

35 seems very low to me.
 
Bebop said:
Meziere electric HD pump is 55.
Stewart mechanical race pump is 140.

35 seems very low to me.
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Indeed. I also have that BMW/Pierburg pump.

I'll do some testing.

I believe this is the pump I have I think.

Operation voltage: 8-16 volts Weight: approx. 2.15 kg Current consumption: 15A (16.5A max.) / (approx. 0.2mA in standby mode) Nominal diff. pressure: 0.45 bar * Flow rate: ca. 116 l/min @ 0.45bar / 166 l/min @ 0.30bar Speed: approx. 4500 rpm

Tecomotive - Pierburg CWA200

Tecomotive develops and sells unique electronic devices for use in vehicles of all kinds.
www.tecomotive.com
 
Some good general info in here.

www.stewartcomponents.com

Advanced Cooling System Basics - Stewart Components

Common Misconceptions Coolant temperatures are not an accurate indicator of metal temperatures. The coolant’s maximum temperature is it’s pressure corrected vapor point. The metal can be several hundred degrees hotter than the adjacent coolant. Temperatures of critical areas must be determined...
www.stewartcomponents.com www.stewartcomponents.com
 
There is absolutely such a thing as too much flow. Cavitation makes for an overheated motor in the short term, roached coolant system in the long term. Amazing how much better a stock system works with a little cleanup on the pump/block interface.
 
CarterKraft said:
This situation came up at work recently and we have scratched our heads a little.

HYDRODYNAMIC

Machine has 8-24v cooling fans on it. Each pair of fans is fused with a 50 amp fuse and each pair of fuses is fused with a 100 amp fuse.
We have a machine that blew the 100 amp fuse. We replaced the fuse and did a override test to command the fans to 100% speed.
At 100% we measured 140 amps on each 100 amp circuit with a amp clamp.
Each fan measured 35 amps x 4 = 140 amps.
The question is do you think there is an issue when measuring this motor current with a amp clamp?

There is a back story where the early versions of this machine had 10x 19a (456w) draw fans and was replaced with 8 of a different fan that CAT can or will not give us the specs of. That machine didn't have the 50 amp fuses but was still fed with 100 amp circuits.
I wondered if they reduced the fan count and forgot to upsize the current rating of the fuse/cables...



1705441052483.png

8fan.jpg
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The Fluke clamp I’ve used on DC has been accurate.
Assuming the fans are brushless Spals they almost don’t need a fuse because of the built in safeties. The wire harness does need a fuse in case the fan malfunctions. You don’t want the wire to burn.
If you run large enough wires then you can get away with sharing fuses. Not that this is right but it can be done.
It sounds like the fuses were not updated for the new fans and they are living on the edge. 19A x4=76A so a 100A fuse would be good.
I would bump up all the fuses if the wire can handle it.
 
HYDRODYNAMIC said:
The Fluke clamp I’ve used on DC has been accurate.
Assuming the fans are brushless Spals they almost don’t need a fuse because of the built in safeties. The wire harness does need a fuse in case the fan malfunctions. You don’t want the wire to burn.
If you run large enough wires then you can get away with sharing fuses. Not that this is right but it can be done.
It sounds like the fuses were not updated for the new fans and they are living on the edge. 19A x4=76A so a 100A fuse would be good.
I would bump up all the fuses if the wire can handle it.
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Changing fuses without corporate approval isn't gonna happen.

I wondered if the fans are not actually programmed to go to "full"speed under operation and by us doing a manual override we are exceeding a soft limit? Poor software but in the beta test software world we are living in I'd say it's possible.
 
CarterKraft said:
Changing fuses without corporate approval isn't gonna happen.

I wondered if the fans are not actually programmed to go to "full"speed under operation and by us doing a manual override we are exceeding a soft limit? Poor software but in the beta test software world we are living in I'd say it's possible.
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If the pulse signal never sends them full power then you would be ok. Not a good design but it works. If the firmware in the fan driver goes full speed then the safety is only in the pulse generator feeding the fans.
The same size fan housing can have a smaller motor and you are running the larger motor version. Someone could have accidentally switched to the higher output.
 
HYDRODYNAMIC said:
If the pulse signal never sends them full power then you would be ok. Not a good design but it works. If the firmware in the fan driver goes full speed then the safety is only in the pulse generator feeding the fans.
The same size fan housing can have a smaller motor and you are running the larger motor version. Someone could have accidentally switched to the higher output.
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These are CAN buss controlled, that is a SPAL option isn't it? I have not confirmed they are Spal just comparing them visually.
 
Bebop said:
No CANbus, just PWM
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I stand corrected, the CAN info was from the TC I am helping with this, I never looked myself but pin 3 is for "fan diagnostic" and pin 4 is for "fan control", two different ECM's oddly.
 
The stock 6.0 water pump should flow 20GPM at 1250RPM and 60GPM at 4000RPM and possibly 66 at 5000 RPM.
The pressure drop across the radiator should be around 5PSI at 40GPM. The block restriction pressure is 25PSI at 4000RPM but a lot of that pressure should be gone once out of the block and only flowing through the radiator.
 
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I have been considering going to a brushless fan. Spal makes a drop in and a flush mount. The flush mount sits outside of the shroud, the drop in sits inside the shroud.

Is one better than the other and if so, how much better?
 
I looked into it on a recreational Ultra4 build. Along with a brushless Fuel pump. They are basically the new tech based on flow need and control. They also seem to add reliability, more torque, soft start, lower amperage, and more water and mud proof (?????) . I question that because I have seen mechanical fans bent from pulling water thru a radiator and sometimes when submerged. Both fans are at the mercy of the, generally plastic, strength. Spal introduced the HD frame series due to offroad hits and G-outs. The attached video builder has reduced the mass of the motor.

Good question for the need in offroad. I know the brushless fuel pumps are used regularly in racing, and sometimes without dual pumps.This minimizes the fuel return issue and heat. On the fan side, I think it is more important to run dual fans for the water radiator. (Conventional brushes or $$$), but maybe brushless for the oil cooling where the fan could follow temperature needs and smaller single fans.

I know Ultra4 and dez trucks use more than 220 amps to run the rig. Most have dual alternators now for heat and redundancy ...as are all sensors, switches, etc. Wireing without shocks has been generally budgeted at $40-50k, and maybe another $30k for active shocks.

EXPENSIVE stuff. How much do you want to win...or run with the big dogs. Generally don't need brushless to win...But maybe easier to loose.

I have chosen redundancy (usually in the trunk or thinker.) over $$$ brushless. (Not raceing) ( Mechanical steel fan or dual elec for water and trans fluid...but two trans coolers for if you took a rock. Dual hi pressure fuel pumps. Box for external low pressure fuel pump, alternator, starter, relays, etc. No mtr oil cooling yet-but have been known to stop in the dunes). Remember that alternators do the work and build heat. Make sure their fans run the best way to cool the diodes...and the rpm speeds are reasonable. We may be seeing more elec steering pumps and shaft motors, adding more challenges. And how about lights? It is adding up. Keep notes. Are we on the edge of 24 or 48 volts for ICE?




 
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Tcdawg said:
I have been considering going to a brushless fan. Spal makes a drop in and a flush mount. The flush mount sits outside of the shroud, the drop in sits inside the shroud.

Is one better than the other and if so, how much better?
Click to expand...
Spal makes a 16" brushless flush mount that is a direct bolt on replacement for the old brushed model. Both have the heavy curved blade design, so performance is very similar but you get the added built in driver benefits ex. safeties, soft start, no relay.
Spal makes a 10" brushless flush mount that has an optimized blade for the brushless motor.
Most of the other brushless fans are drop in or OEM mounts with optimized blades for the brushless motors.
The optimized blades are where you really get the full power out of the brushless motors.
The drop in housings and blades are also designed for deep shrouds that allow more airflow through the core and to the fan blades. Flush mount shrouds that are thin can block the air flow near the corners of the core.
If you are looking for the best performance get a drop in with a deep shroud.
 
It's actually pretty easy to do this. Before electric, The knowledge in the 80's was to have the shroud end about half way across the fan. Who knows now.?? But the box fan shrouds are a bean counters solution. Easy day project. Posterboard and tape (CAD), then open up and cut out of sheet alum. I have done a few with no welding. (Overlap the bottom for bolts. Yes, you have to go all the way around. Learned.)
 

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HYDRODYNAMIC said:
Spal makes a 16" brushless flush mount that is a direct bolt on replacement for the old brushed model. Both have the heavy curved blade design, so performance is very similar but you get the added built in driver benefits ex. safeties, soft start, no relay.
Spal makes a 10" brushless flush mount that has an optimized blade for the brushless motor.
Most of the other brushless fans are drop in or OEM mounts with optimized blades for the brushless motors.
The optimized blades are where you really get the full power out of the brushless motors.
The drop in housings and blades are also designed for deep shrouds that allow more airflow through the core and to the fan blades. Flush mount shrouds that are thin can block the air flow near the corners of the core.
If you are looking for the best performance get a drop in with a deep shroud.
Click to expand...
Good info. Thanks!
 
Isdtbower said:
Kind of a whole different subject. Fans are the most "simple" to get your head around. If there is not a thread, it is because it is so related to end use and needs.
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I used to think they were simple :lmao:

I'll make a new thread.
 
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