I wonder how many of you guys, has ever get to know that electric fans can't cool engine enough...
last night, I went for a cruise in city the temp near 104 F over here...
an hour later when I reached home water was boiling in radiator...
So, I am gonna put the Fan Clutch and shroud back till autumn to save my nerve and avoid headache...

Elec fan's does a great job of cooling an engine.. IMHO they cool better than mech/clutch fans.. OEM's has been using elec fans 20 years.

The prob is most people open up a summit catalog and order a non shourded 14" or 16" fan that moves 1400 to 2200 cfm of air..

Thats really NOT enough air flow. You need 2800 cfm min for a V8 engine.
second is the shroud. With an un shourded fan you loose give or take 40% of your air flow. You need the shourd covering atleast 80% of the rad. core (more is better)

The best fans out there is the OE ones.. Ford taurus 3.8L dual speed fan.. Moves like 3000 cfm on low speed, and has a full shourd..

The 4th gen LT/LS1 fan is another good one.

Aftermarket the closest you gonna get to them is the $200 black magic 2800 cfm fan.

Next is what type cooling system are you running.. If it was boiling over with the right mix of anti frezze in your coolant and a good rad. cap that has 15 or 16 psi then you must have been over 260* and that points to other probs in the car like water pump not moving enough water, lower rad. hose sucking shut, clogged up rad, retarded timing, real lean air/fuel ratio.

I can drive my car for over an hour straight with NO fan at all and it won't get past about 230* and thats no hot enough to boil over with 15/16 psi in the system and 50/50 mix of anti frezze. Then the only time it will get up to 230* is when I have to stop and wait a few min at a redlight.

Rememer when driving above about 50 mph your fan does nothing for cooling. In fact a turning fan at those speeds will block air flow through rad..

Now if you don't have a shourd on your rad. then the air flow from the moving car aint helping you much cause it can't be forced through the rad. The air will just go around, or beside the rad. core

+1 and I'll add to this by saying you need a "sucker" fan to be effective. That is a fan that sits on the engine side of the radiator and pulls the air through.

Thank you night rider for the complete explanation and low end for comment...
Well although I am using twin fans (12 inch each) with shroud that covers %95 of the radiator, they are actually puller... I guess they are not sufficient...
They are stock fans from 405 Peugeot
You are right...
Have to find a better replacement which is hard to find here...
Therefore I have to say goodbye to the elec fan set up until fall.:(
Thanks again...

Your welcome white LT.

I don't have any info on the Peugeot fans so I can't say the amount of CFM they move. Most aftermarket single 12" fans are around 950 cfm to 1100 cfm each.. Some of the better aftermarket 12" ones are in the 1500 cfm range.

So if yours is 1400 or better per fan (2800 total) then that would be pretty good.

Shourd covering 95% of the rad. is GREAT. So thats not your prob.

Set up as puller (mounted on engine side of rad and pulling air through the core and blowing on engine) is the best way to mount and wire them up.

So with all of that said.. Only things I can think of is the fans just don't move enough air, or you have slight probs eslewhere in the engine.

The whole boiling over thing leads me to be believe your rad. cap may not be holding enough pressure.

Water, plane water in the open boils at 212* we all know that, but water under pressure has a higher boiling point. At 15 psi system pressure plane water shouldnt boil untill 257*. At 16 psi 260*.. Add in anti frezze and that boiling point goes up even higher.

Check your rad cap. If the rubber is not sealing good then that will cause the engine to run hotter than it should, plus let pressure out of the cooling system. Most rad. caps for our engines/cars are around 15 psi.

I think those fans are probably outclassed... if I'm not mistaken the 405 was only a 1.9 lliter 4 cylinder. It just wouldn't need much cooling so I don't see Peugeot installing a h-volume fan

Lowend, night rider
Thanks again
here is some pics:
Old blazer Fan and Cut Shroud with Clutch (Works Super Fine in cooling but lots of noise and HP waste):
http://memimage.cardomain.net/member_images/11/web/2315000-2315999/2315727_47_full.jpg
Elec Fans, Modified to fit:
http://memimage.cardomain.net/member_images/11/web/2315000-2315999/2315727_48_full.jpg
Installed, and if you noticed, I have even added a 5 blade little fan on the water pump shaft to intensify the cooling..
http://memimage.cardomain.net/member_images/11/web/2315000-2315999/2315727_46_full.jpg
But NO use
The elec fan was originally Pusher
I installed it on the rear side of radiator (puller) and switched the wiring (positive to negative and vice versa, the fan rpm is the same but since fans blades have been designed to act as a pusher fan, the pulling capabilty is very low
That means I failed in this project:( :whine:

yesterday I put the old fan and clutch+shroud in and it does a great deal in cooling,,,


I have to find another method...

Thank you all...

Now if you don't have a shourd on your rad. then the air flow from the moving car aint helping you much cause it can't be forced through the rad. The air will just go around, or beside the rad. core


Are you sure? I always thought the purpose of the shroud was to make the fan pull more air through the rad, but I figure if you are moving at a decent speed and your electric fan is not on then more air should pass through the rad with no shroud?