I did a quick search and found the following article. Click the following link or you can read the interesting portion I pasted below the link: http://www.mustangsandmore.com/ubb/Archives/Archive-000024/HTML/20000821-1-001706.html I was reading the May 2000 'Car Craft' and I came across something very interesting. They did a dyno test on a 496 horsepower chubby, {yes, I know -- but we can still get some useful info on this...} and they tested different cooling fans to see what kind of drag each different type has. Check this out; Alternator, no fan: 496 hp Black Magic electric fan: 494 hp Thermal clutch fan: 487 hp Nonthermal clutch fan: 485 hp Heavy duty thermal clutch fan: 476 hp High performance flex fan: 476 hp Stock four blade fan: 473 hp Low profile flex fan: 466 hp One piece plastic flex fan: 460 hp OE replacement six blade rigid fan: 449 hp They found the alternator alone, a 63 amp unit, only sucked 1 horsepower. I found this very interesting. That's a tremendous horsepower difference between fans! I use a Ford seven blade flex fan that moves a ton of air, but I'm getting an electric unit! ------------------ SteveLaRiviere/Administrator '72 Mustang Sprint 351C 4V/FMX and not so puny 4.30 Trac-Lok '94 F-150 XL 5.8L/E4OD/3.55 Limited Slip '97 Probe GTS 2.5L DOHC/CD4E ____________________________________________________
Maverick flex-fans fans don't come apart... Mine did. Luckily all it did was cut the upper radiator hose and dent the hood.
That is a great set of stats Ray - nice research! So it looks like a high $$$ performance flex fan is better than stock steel but a cheaper fan is not as good ............. I am surprised by the differences being so big between the fans. And 1HP for an alternator.
I just thought of something else when looking at those figures again. And this would take a little math work to calculate blade pitch and surface area to find the CFM that each fan moves, to do it the right way. But in a nutshell - most flex fans, even cheap ones are 6 blades. And the 2 stock steel blades in the chart are 4 blade and 6 blade. In all HP readings, the stock 6 blade gets beat out by everything. So it would stand to reason that while a plain old flex fan may use a little more HP then a stock 4 blade, the flex fan will use less HP per cu ft of air moved. And only the high performance flex uses less HP then a stock 4 blade. This might be what your performance shop friend was referring to about a stock blade using less HP then a flex. But he was comparring a 4 blade to a 6 blade with higher CFM ratings....... At any rate, it is a cool discussion!
I agree, but after seeing that 20hp drop with the high perf flex fan, unless somebody can change my mind, electric here I come.
the stories about the killing fan , oh yea I lost a buddy of mine an he too lost one --- Yea back in the day when they first came out yes they had problems, I havent heard of it happening in like 20 yrs now ,Its like anything under severe stress yes it could fail , just look at the darn thing once in a while an make sure it has no cracks,, Oh an you steel fans I had a shaft break on the water pump doing 75 mph , an that big ole chunk of steel left a NASTY whole in my hood as it came through, I like clutch fans myself !!!!. elec are good till the sensor fails an then your TOAST !!
And to correct myself, the two guys I talked to did not mention if the fans were on a Maverick or another car. They just said to lose the fan ASAP. Rayzorsharp, once again, you are razor-sharp with details. Those were the kind of numbers I was looking for. 20-40 HP lost from the fan??? When I had that electric fan on for the week before I blew it up (wired wrong, I guess, maybe when I dropped it?) I thought I felt a significant power gain. 20-40 HP on a 180 HP engine is quite a jump, around 10-20%.
So can I convert my OEM fan to a thermal clutch fan just by purchasing a thermal clutch? What does it do ... replace the spacer between the water pump and the fan? I could go for a 10% HP increase ...
I've ran electric fans on EVERY car/truck I've had since I purchased my own car w/ a payment (third vehicle) 66 F-100 w/ 390 FE, 1976 F-100 302, 1990 GMC Z-71, etc If they didn't come with electric I added them. I could tell a great difference in power in my 76.. went from direct drive 4 blade to a 16 or 18'' electric w/ thermostat switch (biggest fan they sold) and it cooled great, no worries, and ran considerably better (only better upgrade was from 2.75 gears to 3.50) Also about the thermo on electric fan going out... if you watch your gauges you will know if it quits, and you can pull over and wire it directly on until you can replace it. Or but a switch underneith your dash and run it that way. Always look at your gauges. I swear by electric fans. Never will I use another flex/metal fan again Also, yes, it replaces your spacer. I think I may have an extra one for a 302 laying around if your interested in it you can have it
Man, now that is some useful information right there! Now you really got the gears in my head turning! There are several cars in my grandpa's field with electric fans. Looks like I got some experimenting to do! There is a '84 Honda Accord in my grandpa's field that has a radiator similar to the size of a Mav radiator. It has a couple 6 or 7 inch electric fans made into the shroud. Just ONE of those little fans moves a tremendous amount of air, way more then the 6 blade Mav fan ever could. I'm thinking I could wire one up to a thermostat and put the other on a toggle switch for a back up and for getting stuck in traffic in extream heat, which has happend quite a few times lately. There is also a couple of old Mercury Lynx's sitting up there that just have one big fan. I'll give that a shot to.
Exactly Just a theory me and my friend have. If you don't run an alternator (drag car) your running off just the power in the battery. Say 12volts fully charged... goes down as it dies. Running an alternator on a dragcar (which I do and a friend does) seems to actually pick up your ET (havent proven it on mine yet) but your running on full 14v which makes hotter spark to ignition... atleast our theory And if it fires better, better combustion, more fuel burnt = more power. So I'll give up my 1hp
One thing to look out for when you run an electric fan (I have the Black Magic on mine)...make sure you have an alternator that can handle the load. I currently have a 100 amp alternator (installed on the way to the Roundup ) and it does OK even with the headlights on and the blower running on 'hi'. Offhand I don't know how much extra the Black Magic one draws, but I know it is alot. I can bet a stock Mav alternator would not be able to supply it properly as well as running all the accessories and charge the battery...just a thought.
