>>> ELECTRIC FAN CONUNDRUM <<<

[Fordsandguns]

Midnight I believe you about the worn out fan on the cummins but I think the idi wouldn't fare as well with a bad fan in hot weather sitting still in traffic.

 

[MIDNIGHT RIDER]

Midnight I believe you about the worn out fan on the cummins but I think the idi wouldn't fare as well with a bad fan in hot weather sitting still in traffic.

I had the same results with the old 6.9 and junk clutch-fan; never a worry about coolant temperatures.

With half-a-million HARD miles on it, the old 6.9 has the original head-gaskets, water-pump, thermostat, starter, and fan-clutch.

If push came to shove, I wouldn't be afraid to drop it in another truck and head to California.

Now, the 7.3 is an entirely different animal; they don't even need an excuse to over-heat.

 

[RLDSL]

****

I hate to say it., but it doesn't take a whole lot of searching to find that the general concensus is that the Zirgo fans actually flow only 1/4-1/2 of their rated CFM which means the things only really pull between 825-1650 at zero static pressure. Add the load of teh rad etc to that and it would round down to roughly 450-750 cfm. Fine for an ac booster or tranny cooler booster, but nowhere near enough to use for main cooling even with a pair, where you live ( I'm right next door, I know how hot it gets)
Considering that the primary market out there these days is little Asian cars with radiators the size of our heater cores, it's no wonder that they can get away with overinflating flow figures.