What the heck does an electric fan do when it's running when the engine is turned off?????? The water pump isn't turning so it's not cooling the engine. And don't try that song and dance about sending air over the engine to help cool it. You aren't gonna get enough air from that fan to cool down that much steel and cast iron. Besides the heat is INSIDE the engine.

Dep

 

Their fans will often run for several minutes after the engine is off.

This lowers the temp of the fluid in the radiator which is still very much connected to the rest of the coolant in the block. Remember water pumps are axial flow and do not block water flow, so until the thermostat closes completely water can ebb and flow through the system even when they are not turning.

No, it doesn't circulate the water by the pump when the engine is off - which would be a lot better (and one of the great arguments for electric water pumps - if the better ones out there really do flow as much or more than higher end mechanical.)

I would estimate 60+% of the system's coolant is in the radiator, rather than the engine and heater core - cool that when you are within a few degrees of boil-over and you just saved losing coolant. Additionally, cooling that much of the coolant will reduce the amount of after-shutdown buildup. Cooling that faster also decreases the time before the system will suck in coolant from the overflow tank.

I hadn't thought of direct convection cooling with the fan. I wouldn't think it was that great either - but don't tell a Porsche or VW guy fans alone won't cool metal....

 

C'mon Wayne...that's a pretty thin argument with that "still connected to the block" thing. Water pumps don't block flow, but there IS no flow with just a fan blowing over the radiator. Pumps have to MOVE the water for the cooler water to get to the engine. Ebb and flow works on oceans and streams via the moon...not in our radiators

Once the radiator has levelled off after filling it with anti-freze, there should BE no "boil over". Or if there is, it should be very minimal.
If you're running that hot that you are getting consistent boil overs, then there is a problem with your cooling system. Better switch to something OTHER THAN an electric fan
What difference does it make if coolant is sucked in from the overflow tank????

Dep

 

to cool the whole system, to prepare for startup after a short down time (like running down the highway to a store, in for ten minutes and out again...).

I *know* even you yankees get hot in the summer!

From the posters here, most have some problems with their C3 cooling systems - any time you can stop from losing coolant you are ahead.

You want as much coolant mass in the system as possible, whether from the specific expansion tank on some models or the combination expansion tank/overflow tank as is more common. The more mass you have to absorb heat from the engine when running to send to the radiator to dump to the air going through, the faster than heat can be transported. Usually more important is when the engine is pushing the limits of the system during hotter ambient conditions (as it has in most of the cars I've ever owned) is if you are losing a little coolant each cycle of startup and cool down, getting the fluid in the overflow into the system sooner lets you know if you have lost a critical amount and that you could be sucking air back into it when you ran out of what was in the overflow tank. (You obviously never want the fluid in the overflow tank to be below the place where the retrieval tube is located for that reason.)

You can't really tell me you never have a cooling problem! If not you have a nice, perfectly unclogged radiator and everything else most are not so fortunate to have constantly.

While trying argument after argument on ancillary issues you keep evading every maximum performance cooling system you ever see referred to uses electric fans. Electric fans simply work better, without requiring perfect shrouding, external air direction and so forth. Mechanical setups can work, but they require much more perfect condition in the rest of the setup. They are an antiquated option which, while being capable of getting the job done, are simply not the best option available. The vast majority of the cars and trucks I've owned or still own don't even have an auxilliary electric fan, but those that are electric run cooler.

You want to switch to an electric fan setup, you know you do....
you will do it.....it's much better than "Cats".....you are ordering some fans as you read this.....you cannot resist the power of the force.....

 

At this point I'm ready to mount a hard metal multiblade fly swatter fan directly to the hub and to heck with effiency! I want a hurricane under my hood...

 

Right! Or maybe mount a second engine just to power the cooling equipment for the first engine. Of course, you'd have to cool the second engine so you'd need...and on and on and on.

I don't understand why people are having cooling issues unless there is something VERY wrong with their engines. Yes, we get REAL hot/humid weather by me and I have NEVER had a cooling problem with any of my cars. Just keep a 50/50 mix of antifeeeze and everything is fine. Hasn't mattered with a non-flex 4 blade fan, a clutch-type fan, or an electric fan that came on my 2002 Monte Carlo. If your car is pissing out anti-freeze every time you stop, then keep the heck off my driveway!!!


Dep

 

"There's no kill like OVERKILL!!!"



Really, though, there's nothing wrong with a functional fan clutch. I don't use them in favor of a flex fan, and am getting away from those in favor of nuk-u-lar electric fans... After an experience like yours with a flex fan, I'd probably not go that route either though....

But those electric fans I will either hardwire or have switch only controllled and not use thermostatically controlled setups - I'm just a dinosaur at heart!

 

..and maybe a nice tranny leak for variety too!!!

 

Better bring some rubber mats if you visit me!!!

Dep

 

Hey Dep,

At the risk of running off on another tangent,

This was before my time, but you probably remember. The really, really early cars did not even have a water pump. Folks also used to throw a handful of corn meal in the radiator to stop leaks.

These engines cooled by the physics of warm water being less dense than cold and rising to the top of the engineand flowing into the top of the radiator, the cooler water from the bottom of the radiator would replace it and the cycle continued, cooler water replacing warm. Most systems still flow this way this way except for reverse flow systems, LT1s etc. But, point is, unless the water is blocked, it will continue to circulate through the cooling system.

BTW, any guy with an 11 sec Vette must be doing something right. I look forward to seeing your time slips. When you can figure out which rear end to run.

 

Clint: Nahhhh...Olivier is still a gumball. I ribbed him again about his trans after he posted YET ANOTHER thread about problems he had. He says he still runs on the street somtimes, although he calls it a full race car. He resides in the land of confusion

I dunno about that water still circulating after the engine is shut off.
I think it would be a VERY SLOW process and the thermostat would close before it made any difference. Take the cap off a radiator while the engine is running and you will see the water circulating freely. Turn the engine off and everything comes to a halt. Osmosis can only do so much

It will be quite a while till I have any time slips. Seems like every day I find something else I need to do. I knew I had to replace all the wiring under the hood. That was no big deal. Now I MAY have to replace the underdash wiring. Much bigger deal and MUCH more expensive.
I know which rear end I WANT (Ford 9 inch). It's finding someone who will install it MY WAY that's a PITA.

Here's what I will be basing my build on:
http://www.z28camaro.com/oldrel.html
The difference is I'm not going to be restricted to the same class as the Old Reliable. So I can do more mods.

Dep

 

That's one cool Z-28.

This from the driveline description:

Rear axle & ratio 12-bolt, 5.57 Richmond Pro Gears

Isn't this a Chevy 12 bolt? Ford parts on a Chevy? What would Z. A. D. say?

 

Yep...Old Reliable is all Chevy with a 12 bolt. Has to use Chevy to remain in Super Stock class. The simple fact is Ford and Dana 60 are the most heavy duty rear end money can buy. Ford is preferred because of ease of changing the rear axle ratios via a drooput rear carrier. Just about every fabricated housing is made for Ford 9 inch carriers. NASCAR uses Ford rear ends exclusively.

Now if I can get a few more money trees to bloom...I'll be all set

Dep

 

I hear that, Bro'.