L322 Viscous Fan Speed

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FEI said:
@Datatek ive read about your mod. Ive decided against it and rather for the electro viscous fan.
Reasoning I dont want that extra load on the alternator. Im guessing those AC fans are around 30amp draw and then the largest SPAL i can fit is another 40 amp. So extra 70 amp almost constant draw in hot weather. So that is roughly a 0.9KW of cooling fans.
That will just cause preamature alternator failure.
I live in South Africa, so those fans are going to be on almost permanently.

So looking at some stuff i can find online:
Horton makes electro viscous fans. One of their smaller units takes a 500mm-700mm diameter fan and can provide upto 60nm of torque through to the fan from the engine. The P38 fan has a 460mm diameter fan and the L322 has a 500mm diameter fan. So at 2000RPM fan speed that relates to 12.57KW. So lets be really conservative and say that the P38 viscous fan uses max 5KW.
How does the AC fans and a huge SPAL fan of 0.9KW comare to 5KW of cooling. Then the next question, if all of that 5KW of cooling wasnt necessary why would landrover put it there?

Then another thing is effiency again. There is energy loss converting the rotational energy to electrical, a really good alternator will probably have a 75% effiency. Then later you want to convert the electrical energy back to rotational in the fan, roughly another 70% efficient.
So in order for your alternator to produce 0.9KW you are going to draw +- 1.2KW of energy from the engine and then at the spinning electrical fan you only going to get out 0.63KW of rotational energy.
So with a viscous fan you have none of those losses. The only loss that a viscous fan will have more than a electrical fan is the extra weight of the viscous clutch itsself.
Click to expand...

Now as much as I enjoy a project "cos I can/want" type thing, also dont get me wrong not against someone trying something new.

Cooling costs power, wherever you get it from be that electrically or physically. So the water pump takes power to move water, which of course it does all the time even if its not needed. The fan viscous or not takes power to turn. So you cant get away from the efficiencies of cooling you need xx of power to cool that engine end of.

So if you live in a hot climate the best bang for your buck is a bigger more efficient Rad, once fitted it takes no power to cool.

My P38 runs a large electric fan and a larger radiator, but then it is 6.3l, the fan very rarely runs while driving around but of course it does in very slow traffic.
I have also ran a car with 2 small fans (1 or both on) with no water pump impellor, it ran a variable speed (temp sensitive/controlled) water pump.

So there are many ways to skin a cat ;).

So all that said, If you need/want better cooling in hot climate run a better rad to start with, then work from there.
If you want to play and try something then thats fine too.
Contrary to my previous comments in this original thread I am pretty sure I have the electro controlled Viscous fan, I also have equip that possibly could measure what you need except the fan Max RPM. But the defender is in the garage ATM so cant even think about trying it.
But ignoring peeps is childish IMHO.

Plus really you would get better response if you had started a separate thread. So start 1 and ask the mods to move this info you have already posted over to it.

J
 
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How do you replace the very hot water in the cylinder head(s) with cooler water from the radiator if there's no pump? Heat rises
 
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marjon said:
I was thinking its a trick question, you KNOW how slippery frogs can be :p.
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1mxnum.jpg
 
marjon said:
Now as much as I enjoy a project "cos I can/want" type thing, also dont get me wrong not against someone trying something new.

Cooling costs power, wherever you get it from be that electrically or physically. So the water pump takes power to move water, which of course it does all the time even if its not needed. The fan viscous or not takes power to turn. So you cant get away from the efficiencies of cooling you need xx of power to cool that engine end of.

So if you live in a hot climate the best bang for your buck is a bigger more efficient Rad, once fitted it takes no power to cool.

My P38 runs a large electric fan and a larger radiator, but then it is 6.3l, the fan very rarely runs while driving around but of course it does in very slow traffic.
I have also ran a car with 2 small fans (1 or both on) with no water pump impellor, it ran a variable speed (temp sensitive/controlled) water pump.

So there are many ways to skin a cat ;).

So all that said, If you need/want better cooling in hot climate run a better rad to start with, then work from there.
If you want to play and try something then thats fine too.
Contrary to my previous comments in this original thread I am pretty sure I have the electro controlled Viscous fan, I also have equip that possibly could measure what you need except the fan Max RPM. But the defender is in the garage ATM so cant even think about trying it.
But ignoring peeps is childish IMHO.

Plus really you would get better response if you had started a separate thread. So start 1 and ask the mods to move this info you have already posted over to it.

J
Click to expand...
For the P38 diesel, the GEMS V8 RAD gives much better cooling but cannot easily be used with the viscous cowl in place. I have a custom made all metal RAD on my LHD P38 but it's not as good as the V8 RAD, less likely to split of course.
Electric fans only use power when they are needed as you said above in slow moving traffic for example. Above about 30MPH the fans rarely run so consume no power.
 
Mark Piercy said:
And the charging system on the 38' is equipped to deal with the two electric fans already but if our mate needs serious extra cooling then a bigger better rad as said is the starting point and then the fan 🤔
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I think the biggest issue is the fact the stat isn't fully open until around 96c. Too hot for these engines but there's no cooler stat available
 
kermit_rr said:
I think the biggest issue is the fact the stat isn't fully open until around 96c. Too hot for these engines but there's no cooler stat available
Click to expand...
The M51 runs at between 85 and 105C as it's normal operating range, the gauge stays just left of mid point between those limits, 95C is optimum. The stat I checked in a pan of water was fully open at about 88C.
 
Datatek said:
The M51 runs at between 85 and 105C as it's normal operating range, the gauge stays just left of mid point between those limits, 95C is optimum. The stat I checked in a pan of water was fully open at about 88C.
Click to expand...
I suspect the diesel has a more normal thermostat and better built than the v8?
I don't understand why they had to make it so complicated.. i mean, it's clever, but why??
 
kermit_rr said:
I suspect the diesel has a more normal thermostat and better built than the v8?
I don't understand why they had to make it so complicated.. i mean, it's clever, but why??
Click to expand...
Ah you are talking about the L322. The fine control of engine temperature on the newer stuff using electronics is all about meeting emissions regs under test conditions.
 
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