[MStennes]

Help, I need to install a fan system on my 69 I have a Be Cool radiator but was thinking a electric fan would be cool, other wise I will have to buy a new fan clutch system since the bonehead I bought this car from had installed a very low budget direct fan set up from the budget section of JC Whitney. Any thought of which way I should go? The car is a 383 stroker pushing about 450 horse power, with a 700R4.

Thanks,

Mike

[KWIK 69]

I've got a 383 Stroker and my 700r4 is currently being built... I'm going to go with the electric fan when I order my BeCool radiator. It seems like I read somewhere the electric fan was recommended... it certainly must be more efficient. (get the pull type air flow, not push)

[chicane67]

Originally posted by KWIK 69:
....it certainly must be more efficient.

Not nessarily so. The fact of the matter is that a clutch system, the correct fan and proper shroud is the most effective at cooling. The main reason that the manufacturers have gone to electric systems are for space considerations. But none the less, either choise has its pro's and con's.

I would consider an electric. You will definately want to look at the Lincon Mark VIII 18" unit. It is affordable and has the highest rated CFM (well higher than anyone else's efforts).

[MStennes]

Kwik,
Are you going with the complete setup from be cool or the radiator and a different fan set up?

[KWIK 69]

Not sure yet, I'll jump off that bridge when I get to it. My budget will be playing a factor here.

I'de definately look into those recommended by the guys on this board, they've been there & done it. I'de also check out the fan that BeCool recommends for your application and check comparable prices and performances.

Good luck!

[HOTRODSRJ]

I must take exception respectfully to the poster regarding the clutch fan set up being the most efficient mechanism for cooling when compared to the electric fan. I think he means compared to a fixed bladed system but I cannot tell for sure. No disrespect meant, but here goes my explanation.

Quality, high-flow electric fans will produce MORE airflow at idle and slow cruising speeds (where it's needed most) and take absolutely no hp per se. Couple this with the want of high airflow on all 134 airconditioning systems, light weight, no parasitic drag on the motor, smaller cubic footprint, higher predictability and reliability...well you get the idea....no wonder OEMs use them profusely. We should too.

Even tho the old tried and true clutch fan set up when working correctly will probably get you by, clutched fans will NOT produce the kind of airflow at idle and slow speeds and are complicated to beat the band compared to an electric motor and switch. This is why their MTBF is lower than electric fans. Clutch fans will also produce parasitic drag of over 15 hp (some as high as 22hp at peak rpms) at higher RPMs regardless of when they "shut off" if there is such a thing....you really can't tell can you?

Moreover, clutch systems produced today are NOT the specifications and quality that were produced of yesteryear by all the OEMs. Many of today's manufacturers tried to reverse engineer these things and there were over 25 differing clutch fan/assemblies specified in 1970 that performed to differing levels depending on applications. For example, PU trucks had clutch/fans that would keep coupled up to 50% more rpms (compared to performance ones) assumming towing and heavy duty use. Cars equipped with air had similar specs. Some were even designed to fit the total capacity of the cooling system in the performance arenas. Today, much to our liking, we are making so much more hp per cube than then and the clutch/fans cannot and are not adequate in most cases for cooling our beasts of fun.

The clutch/fan assemblies that are produced today are relatively non-specific in general and you cannot tell if they are working correctly as well as they are probably eating more hp than you want or need for them too. On the positive side, I do like the look of the fan assemblies in original applications tho.

I used to not run flex fans due to their ability to launch themselves thru hoods and radiators and they were not that great of airproducers either. But a new technology fan product came along from Derale (http://www.derale.com/hdflexfans.shtml). There heavy duty flex series part number 17XXX series got rid of all the old problems of flex fans and produce more air at idle than any fixed or clutch fan that I have seen or tested. They will not come apart and are specified to at least 10000rpm according to the original specification engineer. I use the stainless and chrome 17" on my 69 Ragtop (400HP+ with air) here in Hotlanta traffic and weather and it never comes off the 175 thermostat. I fling this thing regularly with shifts in the 7000 range (with a 17% overdrive pulley....making that over 8,000 rpms water pump shaft speed) and have done so for three years. I just took off the fan this year to xray for cracks and such, the prognosis was perfect health! I highly recommend them and use them on several applications. They are relatively quiet, effective, cheap, good looking, and the highest reliability that you can get and will work with stock shrouds! About $60 from Summit.

If it were mine tho.....with your hp generation and the want for the best, a dual Spal or Derale electric fan set up would blow (pun intended) anything else away! Not cheap tho...

[rolling-robert]

ì recently pulled a radiator with 2 electric fans out of an old Renault van, im gonna use this is in my 383 powered maro in the future.

radiator has about same size as original and prefer the electric fans above the belt driven ones.
because the belt driven turns slow everytime cooling is most needed.

[DjD]

No doubt you'll gain a few ponies with an electric fan but is it worth the extra expense? Here are some test results I got from an issue of Car Craft (May 2000) All these tests were run on Flex-a-lite brand fans except for the factory 4 blade. To baseline things the first dyno run was no fan at all but did include an alternator.

No fan = 496hp
Electric = 494hp
Thermal clutch = 487hp
Nonthermal clutch = 485hp
HD thermal = 476hp
HP flex fan = 476hp
Stock 4 blade = 473hp
Low-profile flex = 466hp
One piece plastic flex = 460hp
OE replacement 6 blade = 449hp

You can see your fan choice makes a difference. The cost difference is quite a bit though and the electric fan they used cost $170 as opposed to the thermal clutch fan at $66 and the nonthermal clutch fan at $56 (remember these are all Flex-a lite products and the testing and prices are from May 2000) Also note that this test didn't go into cooling ability.

Both types of fans can keep your mill cool just like both std and alum radiators do as well. Alum and electric adds a wow factor under the hood but are costly compared to the alternative. I have no proof for you that one flows more air than the other at idle I do feel that most electric fans may actually restrict flow through the radiator and around the engine at higher speeds though. Electric fans also require your electric system to be up to the task and power relays and proper setup is critical. If power fails, the fans don't work. I know a fan belt can fail and cause a mechanical fan to quit working as well so it's a draw unless you are not very good with trouble shooting wires... I bring this up because you hear guys talk about wiring things so the fans run as soon as the key is turned all the time. This is because they couldn't figure out how to trouble shoot and fix the problem or just don't understand how it's susposed to work.

I am using Flex-a-lite's nonthermal clutch pn 5255 and fan pn 5718 ($56 through summit) I had my stock rad recored with the biggest core that fit between the tanks (under $200), a stock water pump and a Robert Shaw (Mr Gasket) 180deg stat ($10 - $12). I run about a 60/40 water to antifreeze mix with no other additives. I have sat in traffic for over an hr creeping along and my 383 didn't get to 190 degs. Moving it stays between 175 - 185 no matter how hot it gets outside.

My point, (as it so often is) is all about budget. If you are not on one your car ought to look and perform like the Mule. If you are on one you need to pick the most cost effective parts to get the job done so you have money for the rest of the project. Nothing worse than seeing a project take years and years and never getting completed do to lack of funds!!

[paulm]

I ran a stock type clutch fan, shroud and radiator here in AZ. I was always pushing the limit of comfortable temps. The temp would consistantly creep up at stop lights waiting for the green even when it was cool here.

I switched to the lincoln mark viii fan and griffen aluminum radiator and I have 0 issues so far. I don't hardly even turn my fan on. Once in a while when I'm stuck in traffic I turn on the fan and no matter if it's hot or cool here the temp drops and maintains 180....(the griffen radiator/lincoln mark vii fan maintained 180 for 40 minutes once in a traffic jam!!).

I am no expert and all those experts that say the OEM clutch fan, shroud and brass radiator is the most efficient must have good reason to say so. I can only relay my experience which is that in my car with no other changes the aluminum radiator/electric fan absolutely beats the pants off of the stock type setup....no question, no gray area, no ifs ands or buts!!

As far as costs go, a universal type aluminum radiator from Summit is $169.95(I'm sure it's made by one of the big radiator places.) and the lincoln mark viii fan is about $140.00. A stock brass type radiator is at least $100.00 and I think in Ricks they are over $200.00 for a small block 4 core. To buy a clutch fan and a shroud from Ricks would be $82.00 for the fan, $40.00 for the clutch and $62.00 for the shroud.

That's $184.00 for the stock type fan and $140.00 for the electric lincoln mark viii(add a few dollars for a power relay and a switch). The brass radiator would cost around $200.00 and the aluminum would cost $169.00 for the summit brand or around $300.00 for the Griffin universal.

I don't see very much difference in costs.....

[ 05-19-2003, 08:47 AM: Message edited by: paulm ]

[Spames]

I agree, and while I can't share the experince with mine yet, I will say that I paid ~150 for my LS1 setup with all the extra relays etc to hook it up. I am re-doing the whole electrical system, so I already had plans to upgrade to a beefier alternator.

I am going from a flex fan, and if it produces an additional 20 Peak HP, there aren't many mods that can compete with that price.

[rolling-robert]

i paid 25 bucks for my radiatopr with 2 electric fans (second hand)

i will turn them on/off with 1 or 2 switches so if im racing the 1/4 mile ill turn them off after that ill turn them on to cool the engine down.

so ill safe a few volts during race...

dunno if it helps, but hey, u never know

[chicane67]

And to constructivly rebuttle.....

I am not disagreeing with what any one here says, I am mearly offering food for thought.

Firstoff my comparison was not a comparison between a fixed and a clutch type it was between an electric and a clutch type. As for a comparison of available CFM at idle and slow cruzing speeds that depends on the fan itself, I agree. Also, there is no substitute for surface area when it comes to cooling.....radiator OR fan wise.

Most electric fan units will not keep up with the high pitch- multi blade flex units for sure. There are very few exceptions to that statment, one being the Lincon Mark VIII unit and the other being that of two Spal units: VA18-AP6-41MA and the twin fan unit 2VAO6-AP6-37A. You would think that the twin unit has more surface area than either of the single units, but it is actually in the middle......the Lincon unit has a 21.5% increase in surface area over a 16" fan blade.

Lets rough the known factors:

SPAL single fan 16" VA18-AP6-41MA, 2360 CFM @ 21.6 amps
SPAL dual fan 11" 2VAO6-AP6-37A, 2780 CFM @ 25 amps
Ford/Lincon single fan 18" F8LH-8C607-AA 4800 CFM @ 33 amps

One 16 inch fan can cool more than 2 x 11 inchers (measurments, less hub diameter).

Example 16" fan divided by 2 = 8"
8 squared is 64 times 3.1417 = 201.06 inches of fan area.

11" fan divided by 2 =5.5"
5.5 squared is 30.25 times 3.1417 = 95.03 inches of fan area x 2 = 190 inches.

18" fan divided by 2 = 9"
9 squared is 81 times 3.1417 = 254.47 inches of fan area.

Now, in comparison to the clutch and fixed blade fans, there is no real empirical data for comparison. But it's overall approach is proven. It is still the most reliable system used to date and as for the expenses, it is less than an electrical system.

Mechanical; fan, clutch and shroud.

Electrical; fan, thermostat, wiring, relay's and switches, shroud and an electrical system that will handle the increased amperage load (IE 90-100 amp alternator) to include the wiring to handle that load......you get the picture.

Lets address the horse power issues. While it has only been viewed of one, both type fan systems have an impact measured in parasitic loss. Wheather or not you believe it, they are closer in measurment than you think. The clutch system's loss is through the H20 pump pulley, which has a known driven ratio. As for the electric fan system, its loss is through the alternator pulley.......remember it takes a mechanical force to create power (non-fusion related) and it too has a known driven ratio. Ratios can help and hurt this as well.

The long and the short of it......lets just say 15 HP for a number loss when using a clutch fan. Now lets look at the electrical side of things. Since it takes HP to create power to run the stock electrical system of the chassis that equates to roughly 6-8 HP. Now lets drop the new high current fan into the scenario without any other upgrades. The current used to run that fan is quite large at start up, some fans actually pull in excess of 100 amps at start-up. That takes power away from other current related devices.....like the ignition. So it hampers its ability to burn the mixture (more power loss). And then lets add the radio (very little current for a stock system) and then an electric fuel pump.....oh yeah, how about driving at night.....and is it hot or cold enough to require the AC or heater? So now were are past the ability of the stock alternator and wiring so that too increases the load.....SO, now we have to make the total amount of current available to handle all of this before your lights go dim and the ignition starts to cut out. So we now have a 10-12 hp loss to take care of all of this.

So basically its a wash, at some monitary expense towards the electrical side. Dennis summed that up quite nicely.........

HOTRODSRJ has pointed to a fixed type fan that I am a huge fan of. I have run the 18" version of that fan on a few cars to include my own and it moves more CFM than that of all the previous mentioned EXCEPT the Lincon Mark VIII fan......they are really, really close! But none the less work very well. Derale now makes a clutch fan that is very similar to the one being discussed, so now you can go both ways.

One very overlooked part is the shroud. I am sure the left hand guys here can agree to that. Well, its the same on our street cars.....we really just need to optimize what we already have.

stenn5- If you want an electric, just remember the electrical system and what is really required to run some of the cool guy electric parts. I'd run the Lincon fan myself, as nothing can touch it for size, cost and CFM rating. I have used this fan on 700+ HP street cars that live in Arizona and they never see anything over 195*, in traffic on a 107* day.

[ 05-19-2003, 05:17 PM: Message edited by: chicane67 ]

[paulm]

Wow...What a great discussion!!

Just to clarify, to get the electrical/charging system capable of handling an electric fan and AC would involve bolting on a later model alternator that charges better and stronger at lower RPMs?

My original alternator which I had rebuilt and rewound to put out 100 amps works fine so far, but doesn't push a full charge until about 1000 RPM. The only thing that I wired into my system was a 75 amp power relay($15.00) and a switch($3.00).

[DjD]

Originally posted by paulm:
Wow...What a great discussion!!

Just to clarify, to get the electrical/charging system capable of handling an electric fan and AC would involve bolting on a later model alternator that charges better and stronger at lower RPMs?

My original alternator which I had rebuilt and rewound to put out 100 amps works fine so far, but doesn't push a full charge until about 1000 RPM. The only thing that I wired into my system was a 75 amp power relay($15.00) and a switch($3.00).

I'm not an electric expert by any means but if you swap in a 100amp alt for the stock 60amp or smaller alt, you may be taking a risk if you haven't upgraded your wiring along with it.

I too agree that electric fans can do the job as can alum radiators. It's the more expensive choice though, as stated my fan and clutch were $56 new, not used and had I replaced the flex fan before having the rad re-cored I bet I'd still be using the stock rad my car had in it.

One personal observation, I have a car that has and electric fan and alum rad and it's operating temps run in about a 20 deg range depending on if the fans are on or not. What I mean is turn on the air to force the fans on and it drops 20 degs. (I know the reason for this has been discussed and bet Steve or Tom can elaborate on why) My car with a nonthermal clutch runs about an 5-10 deg difference depending on if the stat is open or not.

Like almost everything else out there, there is more than one way to skin a cat. The primary reason for design changes in cooling systems came about to keep up with body style designe changes. The old stuff works well if up to snuff. I know lots of cars from the 50's, 60's and 70's that ran fine in Vegas, Plm Spg or AZ heat.

[chicane67]

Paulm- It is not just the alternator itself that has to have that capacity, the wiring of the entire electrical system has to be up to the task.

I dont know how many people know this, but say you were to upgrade to a different- higher wattage bulb larger than the stock 55/60, the headlight section isnt really rated at any more than that. Some of the aftermarket bulbs go as high as 90/140wt. I know, because that is what I use. Do you guys remember the main reason for VW Bugs catching on fire ?? Well there is the answer. Most were of a 6volt system that was upgraded to a 12 volt system and the wire guage just wasnt up to task......put it under load and *POOF* fire in the hole !!

Now just think about when 'we' start adding all of this cool technology, without paying attention to the most important part of the electrical system itself.....the harness. I myself opted for the Painless harness back in '94 to rid myself of any future problems......and I am glad I did.

Man I just saw that Dennis got to the answer before 'Added my reply' so I wont beat it to death and let some of the other guys chime in.....