I keep on reading and seeing a lot of HotRod cars with electric fans. They say it helps your engine get more horsepower because the engine doesn't have to push the fan. I found an electric fan at a junkyard off a 91 Camaro RS. The guy wants $40.00 for everyting. I can mount this fan on my 79 with some slight modifications, but would it really increase my HP and by how much. I hate to spend $40.00 on a fan just to find out that there is no difference. I can spend those 40 bucks on more chrome. Anybody done this kind of experiment before? Does anyone know how much air that fan will push, and did 91's with V6 and V8 come with the same fan?

[This message has been edited by 4U 2 NV (edited 11-29-2001).]

[QUOTE]Originally posted by 4U 2 NV:

New user here. I'm absolutely confident that removing the standard (blade) fan will help horsepower production. Also makes the engine a little less noisy at higher RPM. How much will be determined when I dyno car again. If I could make a suggestion? See if you can get an aluminum radiator to fit your car (if you don't have one already). They may have on at junkyard that will fit application. The most important detail on using electric fan is making some type of shroud (spelling) that seals the fans surface to the ENTIRE radiator core. You want it to pull air thru 100% of the core. I'm in Arizona, around 140-160 coming off asphalt, 406 stays at less than 190 in traffic. I know there are folks who disagree with this fan strategy, dyno will tell...

If it were my $40, I'd spend it on something else. Generally speaking, the factory cooling system works the best in most instances unless you're running something really exotic. The h.p. gain would be minimal.

Mark

With all do respect, "minimal" horsepower is what we are searching for. Unless someone wants to start porting heads, install nitrous, blower, etc, these little discrete modifications are all thats left for a "tuner" to gain a few HP. I've been doing this for years with many street racer budies. All have seen significant gains @ the track by using underdrive pulleys, electric fans, electric fuel pumps, BIG ONE HERE- sealing the cowl to the air cleaner (cold in helps), and finally, removing any weight from vehicle that's not needed for what the car is used for... Just my 2 cents.

Forgot a couple other little HP gainers. Get an A/F meter (Halmeter of something similar). Make sure the car is running proper air/fuel ratios for best HP. Many underestimate the weight of the wheels on the car. Big gains here at the track with light wheels. Another one that's worked well is covering fuel lines with thermal rap, and installing a "cool can" for ice water when pushing the pedal a little. Don't forget the ride height of the car as well. Notice the big boys are very low to the ground; analogy would be pushing a brick thru the air. Just my other 2 cents, hope this helps. All can be done with junkyard parts and creativity....

My 2 cents...

For $40, I don't know, it would be a trade-off. A thermal clutch fan from Hayden or TRW, HD w/AC, would work good. Only comes on when needed, otherwise, it freewheels.

As mbrekke says, The General I'm sure figured this in their equation, however, couldn't tell it by my dually.

You HP gains, I would suspect maybe 8-10, a dyno run before and after would be the deciding factor. However, I'd still would want keep it cool.

Temps of 190-210 degF aren't bad, but as Crucible suggests, outside air is cooler, therefore meaning the engine engulfs less heat.

I'd make sure your present system is working good, radiator has no cold spots, belt in good shape, timing is correct, no holes in rad support to allow recycling of air, etc., etc.

Besides, chrome rusts, but apparently not in Arizona, use stainless steel, alittle heavier, but shines well.

I guess I spent more than 2 cents......

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Everett 68/350/PG/11.90/115mph

I know the question is about fans, but I've had troubles running a cool can. it booged down my engine at the line. Removed it and haven't had any troubles. Now for the fan issue, I agree with the others, if you can get the most out of your engine by doing little and cost minded tricks, the electric fan does work. Just think of it this way, it's one more thing your engine does not have to spin. And by not having your engine work harder, that free's up HP.
Just my thoughts.
Bruce

As far as HP, maybe 10.
I've got dual electric fans on both my cars and even my 67 stay below 200 on hot Texas days, unless I'm in traffic then its gotten to 210 before, but on hot day it usually stays in the 180-190 range.

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67RS CAMARO - STREET CAR, 502 PUMPGAS, HYD. ROLLER, TH350 w/ATI 10" 12-BOLT w/373 ET= 10.47@129 60FT=1.55 ~ ON MOTOR, ET-STREETs w/MUFFLERS
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DAILY DRIVER: 91 B4C CAMARO, 305TPI, TREMEC 5-SPD, 342 GEARS, K&N, CRANK PULLEY, EDELBROCK HEADERS, FLOWMASTER, ET=14.1@98 60FT=2.06
SOON TO BE 383 W/ SUPERRAM

It is me or is my coputer going crazy. My computer would not show the post, and after I posted this one It worked. Now I can see what you guys have to say.

[This message has been edited by 4U 2 NV (edited 11-29-2001).]

4U 2 NV-

Your getting some great advice in my humble opinion. Without taking the engine apart or spending big $$$, you are limited to creativity and small HP gains @ a time. My philosophy is lose as much reciprocating burden on the engine as possible, while keeping it cool enough for street use. Find some way to bring cold air into the intake, never get air from inside the engine compartment if this can be avoided. With some fine tuning (A/F meter) you can really make peak HP with your combination. 10 here, 20 there. All these mods add up to horsepower you can feel in the seat of your pants.

You have hit a rather subjective subject in that the horsepower that you are eating up with flinging your fan around depends on size, blade pitch, clutched or not, and so forth.

I have tested and corroborated articles (High Performance Chevy) to back this up that some big fixed fans can eat up in excess of 40 hp at max rpms. Then again, so clutched models only take 10 ish. Yours fits somewhere in between I am sure.

I am not a fan (no pun intended) of going to the junk yard for electrical components. You do not know what they have been thru and the failure of such can be catastophic to your engine and maybe to yourself.

If you are going to get an electric fan, use an aftermarket one from Spal or Derale. Derale is available from Summit and can be checked out at www.derale.com (http://www.derale.com) and the Spal ones can be checked out at http://faninfo@spal-usa.com/html/dampframe.htm . There dealers are all over the place. Spal is an OEM quality aftermarket supplier of fans to modern manufacturers such as BMW and PORCHE and Derale is a quality fan as well. They are not cheap tho.....$100+, but will move alot of air (excess of 2300cfm) and are reliable components. This is why modern cars, even with longitudinal engine mounts are equipped with electric fans. I have built many a street rod with one. These electric fans come in a variety of differing sizes as well, and the dual spals are the best for Camaro cross flow radiators.

If you do mount any fan make sure to use a relay from the battery to directly feed the fan, and there are plenty of aftermarket sensor switches for you to pick from.

See my article at http://streetrodstuff.com/Articles/March_2001/Top_Ten_Cooling_Tips.php for more on fans and cooling in general.

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STEVE JACK
ConceptOne Pulleys and Brackets
http://streetrodstuff.com/Products/pics/thumb_198_1.jpg
Engineering & Marketing Technologies

[This message has been edited by HOTRODSRJ (edited 11-29-2001).]

[This message has been edited by HOTRODSRJ (edited 11-29-2001).]

There is one other thing that you have to consider when thinking of installing an electric fan. Yes, some belt driven cooling fans can eat up close to 40hp, but that doesn't mean that you will gain 40hp if you switch to an electric fan. An electric fan requires energy to turn just like a belt driven fan does. The difference between the two is how the energy to turn the fan gets to the fan blades. With a belt driven fan, the energy comes, via a belt, directly from the crankshaft of the engine. With an electric fan, the energy to spin the blades comes from the car's electrical system. The car's electrical energy comes from the alternator which, in turn gets its energy fromt the crankshaft of the engine via a belt. The horsepower gain that is associated with an electric fan comes from its better efficiency and the fact that it isn't always on, not because the engine isn't spinning a fan blade (the engine really is indirectly spinning the fan blade). You get the full horsepower gain when the fan is off. This is where an electric fan has a big advantage over a belt driven fan because when the car is going down the highway, a fan usually isn't needed. An electric fan simply turns itself off in a situation like this which reduces drag on the motor and gives you better fuel economy. A clutch fan mimics this function to a certain extent, but never totally relieves the engine of having to spin it.

If you decide to go with an electric fan, make sure that you take the time to set it up properly so that you can take full advantage of everything that they have to offer. I would set it up so that it turns on and off automatically then install an override switch that completly turns the fan off. This will give you the ability to keep the fan from coming on during a drag race and put a little more power to the rear wheels.

Cameron you are right about the 40 hp thing and actually it is the NET savings one is interested in. Even the most robust of electric fans only eat up a fraction of a hp (most take only 260 watts)and even when on are a tremendous saving over the most minimal mechanical system. A Spal Electric 2400CFM fan requires 22 continuous amps and 285 watts, less than 1/2 of a hp.

It's interesting that even the best clutch or flexer will take up over 10hp at 5000RPMS. Varies with models etc. Chevy Hi did an article on this I think last year or maybe in the last 18 months, but I can't find the issue or I would put it up for bedtime reading. They also corroborated the alternator reading of about a hp at most.

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STEVE JACK
ConceptOne Pulleys and Brackets
http://streetrodstuff.com/Products/pics/thumb_198_1.jpg

[This message has been edited by HOTRODSRJ (edited 11-29-2001).]

Sure an electric fan will keep your engine cool. You will gain "some" HP. I really don't think you will "feel" the difference in the seat of your pants. I run electric fans on my cars, for several reasons, 1. The minimal HP gain, 2. It really cleans up the engine compartment if done correctly. If you decide to run an electric fan/s, there are a couple things you should know/do, 1. Be sure to wire it through a relay (not just a switch) fan motors draw a lot of current and it will just be a matter of time before you melt/burn up a switch without a relay. 2. You SHOULD also install a fuse in the circuit (30 amp will usually do the job). 3. Install the fan as a puller (installed on the engine side pulling air in from the front of the car towards the engine), fans are more efficient when installed this way, 4. It is also a good idea to have the fan controlled by a thermostat (electronic) this prevents you from forgeting to flip the switch before it's to late, there are several types to choose from (stick on, push through, cathidor <sp>, adjustable) these will turn your fan on and off for you. I also install a switch for back-up incase something goes wrong with the thermostat (not very likely or common).
There is nothing wrong with buying a used electric fan, just test it before you pay for it (all it takes is a battery). If it spins freely no grinding or smoke, it will be fine. Good luck whichever way you decide.

Royce

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70 Camaro 383ci
69 Camaro 385ci
2000 GMC Z71
Link to my 70
http://profiles.yahoo.com/camaroman7d

[This message has been edited by camaroman7d (edited 11-29-2001).]

HotRodSRJ,
I agree. That is why I said that one of the horsepower gains that is associated with electric fans is due to their much better efficiency than belt driven fans. 746 watts make up one horsepower. The fan you speak of requires 285 watts of power to run it. Since there are numerous energy transfers that have to take place in order to get that 285 watts of power from the engine, actual parasitic drain on the engine will be much higher than 285 watts. It would probably be closer to 2-4 hp (this is just a guess) because of the power lost between all of the energy transfers. That is still much better than losing 40 hp when the engine is at 5000 rpm.

Belt driven fans aren't really all that inefficient. Their operating parameters make them drain all that horsepower. They have to move as much air as possible at 800-1000 rpm. In order to do this, engineers had to give the fan blades alot of surface area and a high pitch. This worked great at low rpm, but when the fan is spun at high rpm, parasitic horsepower loss is great. The constant rpm that an electric fan spins at allows the designers to design a fan blade that will flow the most air and use the least amount of power.

I'll go ahead and buy the electric fan then. The reason I want to buy it at a junk and not from a shop is the money issue. I can spend $100 on a good fan at the super shop but when it burns out or breaks I have to spend another $100, but if I get it at the junk yard if the motor burns out I go and buy a new lifetime warranty motor and that's the last time I buy it unless one of the fan blades breaks. I have a seven blade fan with a HP clutch and here in TX my car runs 200-210 with a 160 thermostat. I like the way the electric fan looks too. When I floor it it sounds like my car is an airplane. That fan sucks air like crazy at High RPM's, but al low RPM nothing. All you here is the fan and not the mufflers. If you've installed an electric fan can you please e-mail me or post how you wired it or which whould be the best way. I wanted to run a stright wire from the starter to the fan, so that when I turn on the car the fan would kick on, but by what I read It's not a good idea. Thank you for all your input, learned alot today.

Excellent points by all. I'm a new user here, and I am impressed with the technical knowledge in the group. Sounds like you guys have tried all the R/D I am.

Agree with the relay suggestion, running the thermostat switch, and I would add to put this on a switch that you can control from inside the car. Someone mentioned the MOST HP gain comes when the fan is off and not drawing power from alternator. I agree and this is why I flip the switch off when I leave the starting line @ the track, turn back on when I hit the finish....

4U2 NV, Have you recieved info on how to wire the fan? If not e-mail me and I will put something together for you. I just don't want to bother if you already have what you need.

Royce

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70 Camaro 383ci
69 Camaro 385ci
2000 GMC Z71
Link to my 70

http://profiles.yahoo.com/camaroman7d

just thought i'd chime in with my experience.
when i first got my nova in the spring of 99, it had the stock 307 and stock fan. ran pretty good, and kept it's cool. just for kicks, i threw on an electric fan i had laying around off an 86 fwd buick somerset with a 4 cylinder. the little 307 actually seemed to pull like a stock 350- major increase in noticable power. also gained 4 mpg. i still have this fan and radiator on my 400 horse 355 that now resides in the car, and i have 2 summers and about 10,000 miles on it- never overheated yet, and i drive the thing all summer.looks better, too.i am going electric on all my future cars. one other suggestion to go along with the fan- get a late model, high amp alternator. easy install, and makes everything work a lot better.

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1971 Nova(looks like 69 camaro from underneath!)
355sb, vortec heads, HOT cam,T-10 tranny, 3.70 gears 16" IROC wheels

4U 2NV, You have mail.

ROyce

I would look at what the factory hi-performance engines come with. (the early models)I think they use a seven blade fan (which is special) and a clutch to drive it.
It's hard to beat the factory hi-performance parts! The only draw back is they cost more but are worth it because you know it will work day in and day out.

2 more cents worth... It may not be possible to have the best of both worlds, but I have a setup that works pretty well. I was looking through the electric fan section at the local salvage yard when I came across a fan from a 98 Cobra.(yea, I know, the purists will hang me, so don't tell anybody, hehe) After cutting off the extra mounting tabs, the fan fit almost perfectly inside the stock fan shroud. I fastened it to the shroud as far away from the radiator as I could get it so that it would pull air through as much of the radiator as possible. I have it wired through a 40 amp relay, with a manual switch, and a thermostatically controlled switch in case I forget to turn it on after a run. (I drive it probably 30/70 street/strip). If I'm going to be doing a lot of driving on the street between races, I still have room to install a flex fan on the water pump pulley with the electic fan still in place inside the shroud. I guess the electric fan doesn't cause too much restriction because it doesn't get hot even with the fairly warm Texas summers. I mainly run the flex fan on the street because of the current draw of electric fan.(16 amps on low) If things really got hot, I guess I could run the electic fan at the same time? Hope you find a setup that works. Good luck!


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David
68 SS Camaro (377CID, 11.633 @ 115mph)
72 Chevelle (350CID, 13.42 @ 99)
73 Nova Hatchback (under construction)

I have tried all kinds of electric fans, and nothing kept the car cool enough during the hot So. Cal summers going to the criuse nights and back or driving to track and home.

A flex fan with a shroud can pull about 4000 cfm, no elec fan can do that, and this is what kept my car cool.

Besides when I go to the track, I just loosen up my belt a little so it slips when I rev it, it cant be sucking up more than 1/2 a hp

The nice thing is there are no wires or switches to flip , and no more overheating, when I'm on the street!!

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1969 Chevy Nova 383 SB Dart 2's Roller Motor, 4.11 12 bolt TH350 10"conv

<BLOCKQUOTE>quote:</font><HR>Originally posted by cooldude:


A flex fan with a shroud can pull about 4000 cfm, no elec fan can do that, and this is what kept my car cool.

<HR></BLOCKQUOTE>

cooldude,
Where were you able to find this information? I have always wondered about the CFM ratings of stock fans/shrouds, but have never been able to find it...

Okay I own a 91 Rs with an electric fan. The electric fan wasn't enough to cool my motor. It isn't hp your looking for in a fan it is cooling capabality. I think you should trust me on this. I am going to run a BE KOOL double fan setup just to cool off my small block. Engines don't like to overheat. Its not good at 240 when the thermo is a 160 degrees.

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It is better to burn out than fade away

A fan from a Lincoln MarkIIIV, pulls over 5000 cfm. Vintage Air sells a version of this fan with a shroud.

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68 468 700R4, and here it is;
mutert23 (http://home.earthlink.net/~mutert23/)

Hey MarkM.....I have two questions about the Lincoln fan. If you know this.....maybe not, but it's pretty strange to me...One is why would a Lincoln need such a monster (it's not like they have huge amounts of hp to cool and maybe just maybe it's the radiator size (small)) and how in the heck do they keep up with the wattage requirement (got to be in the 650Watt range) for the fan to operate and what is it's dimensions? Inquiring minds want to know!

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STEVE JACK
ConceptOne Pulleys and Brackets

I replaced my stock 2 row/flex fan combo with a black magic fan and 2 row aluminum radiator and never looked back. One think I dont think anyone has touched on is the fact that you can cool the car better between rounds at the strip with an electric fan. I know if I am making a lot of NOS passes the car tends to heat up and stay hot. With the electric fan, I can spray the radiator with mist and run the fan and keep the car at a consistent temp. This has really helped me. My $0.02...

Steve I really don't know. For that matter I guess I really don't know if it pulls that much air, since I never tested it or anything. That's just what I have read. Alot of guys over at chevelles.com have put these fans on their chevelles, and they all give them rave reviews. Most do say that you have to have at least a 100 amp alternator and wire it to either two 30 amp relays or a 75 amp relay. Do a search over there, there are many discussions about the fan and some have pictures.