Not gonna answer the question then huh? What exactly did you measure in your high school auto class? Because I can pretty much guarantee that what you "tested" doesn't prove what you said.
I am willing to bet that I have read better books, and I have done far more than just cherry picking things from books I don't have a background in- I have formally studied both thermodynamics and fluid dynamics at a level far beyond a basic radiator.
It's true, not every automotive cooling system uses a fan shroud and not every one needs one. If spaced properly the fan can work adequately assuming the whole system has been well designed.
But that's not the same as saying it doesn't make a difference. Without a shroud, the fan will not pull air consistently across the entire radiator core in most systems because the fan is smaller in diameter than the surface area of the radiator. And either way, you're still losing efficiency because you're not directing the air coming off the ends of the fan blades. If the system is good enough the lost efficiency may not mean the car overheats, but again, that's not at all the same as saying it doesn't make a difference.
A fan that is properly spaced in a fan shroud will be more efficient than one that is not and certainly one that doesn't use a shroud at all. Given a particular system an incorrectly spaced fan in a shroud may not work better than not having one, but that depends on the particular case. I don't want to assume too much, but given you're referencing a basic high school auto class I'm guessing you just looked at coolant temperatures, not actual air flow and certainly not the thermodynamic efficiency of the system. So sure, maybe the particular car you tested maintained its temperature either way. But that doesn't prove the shroud doesn't make a difference, it just proves that the cooling system for that particular car was robust enough under the very basic conditions you tested not to have a noticeable difference with the basic equipment you used.
I’ll answer this bullshit post and then I’m out. I’m tired of arguing with arrogant idiots. Yes, you are one of them.
I can tell you how I KNOW you don’t need a shroud.
I was just working on a car yesterday. Didn’t have a shroud. Why not? Because I put it together and the fan is close enough it does MATTER.
How do I know it? Because it never over heats. Ever. It was 90 plus yesterday and sitting in traffic and running down the freeway the temp gauge didn’t even wiggle.
I could pull all the spacers off, fit a shroud and all that and it wouldn’t make a pinch of **** of difference. Nada. Zilch. Zip.
I know that busts your balls because your books say it ain’t proper but I don’t care about your books or your schooling. All that did was make you scared to think for yourself.
In the automotive world you are so limited on space that you can’t, under normal conditions over speed the pump or get the radiator too big or any other nonsense.
There just isn’t room. So you can disabuse yourself that you could even do it. You can’t.
So when I say to:
Buy the BIGGEST radiator that will fit. with TWO CORES. More cores isn’t better. And get it in aluminum. It’s lighter and will cool as good or better as anything else. That’s 26 inches in a Chrysler. Can you hack the core support up and use a big cross flow radiator or some nonsense but I don’t cut up cars like. No benefit.
Get a HIGH FLOW water pump. Arguing this is absurd but I’m sure you’ll try. The pumps cost the same so why not?
Oh right, because you put the fear of God I to people with the threat of cavitation. I’ve never seen it at the pump speeds we can get.
A HIGH FLOW thermostat. The best are Stewart Components. Every one of those I’ve used will maintain their rated temperature. Some of the others don’t. If I have a 180 that’s where it should run. Unless of course you want to make the cooling system as borderline as you can. I won’t do it.
For most guys on here you can drive the pump as fast as you can get the pulleys to do it.
I forget how fast the pump is over driven on the car I fixed yesterday but it’s more than 6% but it’s 10 over or a skosh more.
Get a mechanic fan. Period. No clutch fans, no trick ****. The power you save with electric fans is ate up by the power you lose when you can’t keep the engine cool.
See how simple and cheap that is? You buy one radiator. One pump. One thermostat and one fan.
No guessing. And it will cool whatever you have.
Of course being the professional argue-er you are, you’ll cry and whine that I didn’t do any math and didn’t check with a qualified engineer and professional bullshitter like you.
Too bad. Doing it my way saves money and time.
Now go away. I don’t answer to you. I’ve wasted my last second trying to convince you you don’t have a ******* clue what about cooling an engine. An engine in a car, not a book I mean.
