Originally Posted by The13Bats

Sounds like some confusion I hope I don't add to it tossing in my 2 centavos,

The 'stat is for getting the engine up to temp faster, and keeping it there in cooler weather,

What Zero1niner is doing is somewhat flawed, he is running a 195 stat, so he starts the cold engine with cold water in the cooling system and the engine starts to heat up,
The water in the radiator is cold, if the fans are on even cooler,
The 'stat opens and now a surge of cool water is circulated from the radiator to the engine,
Depending on water temp, ambient temp and other little things the stat might close, while heat builds up again and the cool surge of water happens again,
This will happens a little or a lot depending on all the little variables I mentioned above.
The idea that a 'stat holds water in the radiator to allow it to cool is false.

And this is where Zero1niner is seeing wild drastic needle drop on the temp gauge, I have seen this in my cars but it will eventually even out where it will want to run or it will creep up if we have an overheating issue, but no, it will not stay at 170.

I highly doubt the temp gauges in our c3's are accurate, I plan to do some testing on mine when my car is home, I have to tackle my custom cooling system anyway so it will be part of that.

When I said Zero1niner's tests are flawed it's because this isn't really a real world test at least as far as I am concerned,
My 383 and 454 with the Taurus fan eventually started to overheat, ( I will not go into what was the cause just yet )
To get my engines to overheat took an hour or more of stop and go real world driving in real world conditions, ironically it would love to creep up at a long stop light on a hot day but try to driveway test it and waiting for it to overheat was like watching paint dry.

Now you question the fans, I do to, I realize a lot of people install the fans and say they keep "their" car cool, what are their driving situation, their weather their engine build etc, no two situations are the same,
What bugs me about these budge cooling threads is when it comes to fans no one knows and no one cares the CFM of the fans, this is really important,
The Focus fans were made for 4 cylinder cars, not even hot 4 lungers,
The dual fans are different, I am betting one is engine cooling and one is the auxiliary for AC on the Focus, the blades are different they do put out different CFM's and what is that CFM?
I see a few on Google guess at it but no real tech, "It cools my car" is not real tech,
What saves a lot of these people who use budget fans from overheating is the big bad Dewitts radiators.

If your engine is a stock low HP ( well under 300 ) no AC and it's not 100 plus degrees where you live never stuck in traffic it might work,
You simply need more real life testing to be sure, this is why I suggested while testing run both fans on toggle switches so you know what is on and when...

Originally Posted by Zero1Niner

Hey Bats,

You're totally right. I dont consider this well tested by any stretch. In regards to the starting engine with cold water part, im not sure how my setup would be any different than what was factory. The car came with a 195, and an engine driven fan that I realize has a temperature driven clutch, but still spins when I start the car.

Anyway, I know my system needs some adjustments. I am already working on the BMW dual temp setup in the background. The big mission right now is smog, hence the reason for the 195 thermo. Everyone keeps telling me the hotter the better for smog. Once I am through that, I want to put the 180 thermostat back in, and then install the dual temp sensor in the manifold to better control the fan speed.

Until the summer arrives, I will have no idea if this setup will actually hold up or not. I hope so, but not sure. Seems a bunch of others have made out pretty well with the same setup, so hoping it works out for me too. If not, I will move on to plan B...which I have not figured out yet.

Originally Posted by Amorget

How is an aftermarket system any different except that you get a nice claimed CFM?

Originally Posted by The13Bats

Claimed?, so Spal, flex-a-lite both lie? never tested their fans? I will not get into that type debate

Originally Posted by Amorget

Their CFM claims are behind what kind of radiator or no radiator at all? How tight of a fin spacing, etc etc etc. All those things affect the CFM and aren't what your engine has. My point was basically your main complaint about OEM fans could be said about the aftermarket fans, too.

At first it seems you have a shining point but it is not with out it's flaws,

While I agree I have no more idea as fact than you do how Spal, Flex-a or any aftermarket fan companies does their testing but I believe it is acceptable to believe that they want to boast the largest possible CFM so they test the fans with no other resistance than the CFM meter,

While you are correct that a radiator can vary as can other things if the fan is being tested without any restrictions it gives me a base line idea what it will move, I have that tech with aftermarket not with stock.

So lets say only for conversation that a 12" aftermarket bat-fan puts out 1000 cfm then I know that is too small for what I desire, if the 15" bat-fan puts out 3000 cfm then I know that is what I desire.

Of course Companies like Fords are not going to waste time posting how much CFM their fans move because they are not selling fans to the after market car world.

Since you brought up variables like radiator make model fin spacing row count etc, you might have just put another nail in the coffin why I am not being sold on a stock fan,

Have you ever noticed fan designs vary a heck of a lot, blade count, style, etc,
You ever notice that most if not all the cars that the threads about using stock fans are pulling the fans from cars with very skinny radiators ( 4 and 6 bangers )
It's save bet to believe that the factory designed the fan to work with that skinny radiator, so will that fan even pull well through a thick custom radiator like my custom Dewitts.

On the other side of the coin aftermarket fan companies do design their fans to pull through thicker after market radiators.

Here is a copy of the fan testing that Tom Dewitt pay out of his pocket to do for people like us,
While the Ford mark fan moves basically the same cfm as the dual Spals it does it at the price of much higher amp draw,


I understand what you are saying about the shrouds and agree with you there, but to me fans and shrouds are different aspects to cooling and even a number of OEMs (Thirdgen F-bodies come immediately to mind) don't use shrouds.

You brought up another great point but trust me I have done my homework on this subject,
How old is the technology on 3rd gen f bodies?
a number of years ago I thought what I needed was a GT40 replica, so I started buying books on the real car I recall those top of the line 60's racers used what looked like desk fans with no shroud for their radiators and or oil coolers, while these antique fans helped they were not very efficient.
As we move forward and fan technology moves along too we really do not see any modern fan stock or aftermarket that do not have a shroud, a ring around the blades is a type of shroud.

Cooling system designers learned that a shroud is very important in fact search around the forum see how many people have had serious overheating issues solved by simply properly spacing the fan in the shroud and I am talking old engine driven stock c3 set ups.

A shroud will make or break a fan, period.

My point was not that after market look so good and stock look so crappy but that IS the case,
But in this situation I do not care about looks but rather function, it need at least 70% of the radiator covered with shroud, if you cover more then the shroud needs to be vented so when you are moving at speed air can get out of the shroud when the fan is off,

While I am happy for the lucky fellows who chime in these threads that their uber hp street beast keeps it's cool with a stock bc radiator and stock whatever fan, I am cheap as they come but I anted up for the Dewitts radiators because it's without question the best.
I will not 1/2 *** it with the fan what I think you are mis understanding is that I have any clue which fan I plan to run, I am not sold on any fan at this moment, if I could make a shroud for it I would try my two speed Taurus fan but the factory shroud lacks too much.

Originally Posted by Zero1Niner

Although not directly related to this thread, I did pass my smog today...barely.

Not sure what I can do to not cut it so close next time.