LA block 360 won't stay cool
If you SPEND THE MONEY on an electric fan you can get one that will MOVE HELL outta some air. Thing is, most people try to cheap the hell out after they spend 3K plus dollars on their engine and get a shitty electric fan. That's where some of their bad rap comes from.
That said, I still prefer a good old Mopar Performance viscous fan myself. I guess I am just an old fart and that's ok too.
This is exactly true. Pretty much all the complaints I see about electric fans are because of crappy electric fans, or lousy controllers. Those two things will make or break using an electric fan. The most expensive electric fan isn't necessarily the best either. Mine cost a $100 and kicks ***. And there's nothing wrong with using a mechanical fan with a viscous controller. If it works, it works. They're a lot easier to set up, fewer moving parts, and they last for a really long time. But they're not the best solution for every application. Neither are electric fans.
Ok, so, that's not a
proof, that's an
example. And Rusty already posted the reason for this. A modified factory shroud working in conjunction with an unknown fan that was not intended to work with a modified factory fan shroud, combined with who knows what for a controller.
I'm sure there are lots of people that have used crappy electric fans with a cheap controller that switched back to mechanical fans and had better cooling. But that's not because an electric fan can't work better, it's because the electric fan and controller they were using was inadequate. If I bolt a 4 blade mechanical fan from a 1950's chrysler straight onto my water pump pulley in front of a 400 hp small block and it doesn't cool well enough it would not be proof that mechanical fans are junk, just that I was using the wrong one.
By the same token, my electric fan set up works better than any mechanical fan that I tried on my car. So, there's an example against. It's not
proof, but it shows that some mechanical fans are not better than some electric fans. Just like some electric fans are not better than some mechanical fans. The key word in both cases is some. This is not an "always" situation.
I'll leave off the pictures. I get it. There are more losses involved with an electric motor. You can leave off the equations and just quote the 2nd law of thermodynamics. Rather than using mechanical energy directly, you're converting mechanical energy into electric energy and back into mechanical energy. That
has to involve more loss than just using the original mechanical energy. There's a percentage loss from both the alternator and the electric fan motor, no way around it.
But, that's not the whole story. For that comparison to work, you'd have to be spinning the same fan blade in both cases. You'd also have to be spinning it the same amount of time, and at the same RPM. None of those things are true. The fan blades are different, they're spinning at different and variable RPM's, and they're spinning a different amount of time. Electric fan blades usually spin at one or 2 different ,constant, speeds. If designed properly, they will spin at either the most efficient speed, or the speed that results in the most cfm, or maybe both if it's a 2 speed. Mechanical fan blades spin over a wide range of speeds, and just like looking at horsepower on a dyno curve there's a peak efficiency that will come at a certain rpm and a peak cfm flow that will occur at another rpm. If you're spinning your mechanical fan at 2,000 rpm and the peak efficiency is at 3,000, you're losing efficiency. And of course, any time the mechanical fan is spinning that the electric fan isn't is 100% loss. If you use a good fan controller the electric fans will be controlled more accurately than with a fluid coupler, and so, less loss from spinning the fan when it doesn't need to be. And they there's other considerations, like the weight of the mechanical fan (usually metal) compared to the electric fan blades (almost always plastic). And if you're running a fluid coupler, the weight of spinning the coupler as well. The heavier the rotating mass, the more energy it takes to spin. And then, there's the accuracy of the fan controller again. A programmable electric fan controller can keep the engine in a very small operational temp range. Like, 10* small. If the engine is always operating at it's most efficient temperature, the engine will be more efficient. And a few percentage points of efficiency from the entire engine is worth a lot more than the percentage loss between the different fans.
You can design mechanical fan set up that will outperform electric fans, absolutely. You can also design an electric set up that will outperform mechanical fans. Since there are very limited options for viscous couplers that will fit on these cars, your options are limited for mechanical fans. They'll still work great for all kinds of applications. But not EVERY application. That's my only point here. You just can't say "mechanical fans are more efficient". Sure, maybe in general. But not necessarily comparing one certain mechanical fan to one certain electric fan. It depends on the fans and application. And efficiency isn't the only consideration, function is arguably the most important. The point of the fan is to keep the engine cool. If it takes a little more energy to run the fan, but the fan does a better job of controlling the engine's temperature, the function can outweigh the efficiency.
