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Originally Posted by BillabongXJ
16" flows as much as 2 10" fans. This chart 1900cfm and 650cfm.
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They are terrible fans you are showing there for a start so lets just make that clear, this is particularly so when you have a fan pulling 230W for only 1900cfm in the 16" (should be only be around 80W for that same flow in a decent fan). Like I said a half decent 10" fan is around 1500cfm for about 80W so maybe start with a chart that has a 10" putting out around this then look at what their 16" fan does, so using that chart you found for anything other than saying "they are really crap fans" is a waste of time.
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Electric fan is used with shroud sealed almost hard against radiator. |
Almost as bad as running the fan overlapping the radiator with one side open to free air...... You need a gap to allow the blades to operate at a higher pressure (move a lot more air while reducing load and wear on motor) and to ensure that the blades don't/can't hit the fins along while ensuring the vibrations don't wear through on the sides where it is touching the radiator (especially on a aluminium radiator).
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Over diameter wont be an issue with air being pulled through the radiator. Gases can travel upto 800km/h. An intact original shroud would help direct the suction to the radiator core. |
I don't think you understand the blade element theory or aerodynamic principles at play here, suffice to say you are probably losing over 50% of the fans possible capacity setup as per previous image, as a result it will run hotter and draw more load.
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The half shroud was done by someone for convenience to take it off the vehicle. Im trialing my mark II fan which has a full intact shroud, pics in previous post, and the temp is staying straight up and down. |
I absolutely get that people are doing it because it is easy, that doesn't change the fact that there is a far better way of doing it for around the same money and I would imagine it probably works out being much easier to install as you don't have to make a fan fit an existing shroud.
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Originally Posted by junglejuice
My electric fans run in series when on low speed so each fan gets approx 6-7v meaning they run considerably slower then when running on full power, and yet they still cool very well in traffic, hmmm...
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Ummm no one is arguing there, probably should read again
, what was being stated is the electric fan (or fans in your case) will be running a lot more air through the radiator when engine is at idle then the clutch fan will be even if the electric fans are at half speed.
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Also the bottom of the fan isn't "blocked" it is ducted albeit reasonably sharply.... |
More or less the same as being blocked as the really low pressure zone and parasitic drag will eat any benefit you might gain from having a slightly large opening on the other end of the restriction. You are interrupting the intake side of the fan, even a little bit of restriction has great impacts and here we are talking about 2 massive square restrictions before we even look at modifying the the shroud or ......