Opinions on the Be Cool Electric fan/Radiator Unit.

[BiggBrakefuelie]

Hi fellow Shark owners. I have just ordered a Be Cool Radiator with the electric fan kit and will install the unit next week.It is a duel fan making the engine fan obselete.Has anyone else done this modification?I am hoping to gain some gas miliage maybe even a few marginal horses due to less drag.Anyone tried this on a late Shark?

 

[Vettehead Mikey]

One of the biggest misunderstandings in the hobby is with respect to the stock mechanical fan and clutch. When the motor is at it's normal operating temperature (say 180 or so) the fan clutch 'releases' internally and transmits vitually no power to the fan itself. The loss is less than 1 horsepower. Since almost no power is lost, there's no power or gas mileage to recover.

If the motor is running hotter than normal, typically while stopped in traffic, the clutch engages, running the fan up to it's rated speed and drawing huge amounts of air throught the radiator. Once the engine cools the clutch releases. While the clutch is engaged the probable power consumption is 2-3 horsepower at low engine speed.

Who needs all the complexity of an electric fan, wiring, switches, bigger alternator etc?

Don't let somebody fool you thinking that you're gaining horsepower by using a non-engine driven fan - you have to drive the alternator to provide power to run the fans. No net gain.

 

[Jack]

Typical car alternators are about 85% efficient.
Let’s suppose you have a 70 amp alt that makes about 14.9 Volts.
Also, alts respond to load, so if your elec system is requiring less than 70 amps, the net horsepower loss would be correspondingly less. Amps times Volts = Watts. One Horsepower = 745.7 Watts.

Here’s a formula to determine HP loss from alt. (14.9 volt 70 amp alt):

Alt volt output times alt amp output/745.7 = gross hp used:
14.9 volts X 70 amps/745.7 = 1.4 HP.

Then correct for 85% efficiency:
1.4 HP X .15 = .21

Gross HP Used PLUS HP efficiency loss = NET HP used:
1.4 + .21 = 1.61 net HP used.

So at FULL LOAD your 70 amp alt uses up less than 2 HP.

Seldom if ever does your car's entire system demand a full 70 amp load.

Let’s suppose you have a typical dual-motor electric fan … it probably pulls a max of about 25-30 amps with BOTH motors running. Do the math … you’ll find those two electric fan motors’ load on alt ends up using LESS THAN ONE HP. Note that when the electric fans are not running they do not create a demand on alt; therefore NO HP loss.

Engine driven fans are more reliable than electric fans. But engine driven fans have more space limitations and require more HP than do electric. Engine driven fan CLUTCHES do fail … when they do, more often than not they tend to “Lock Up” and fail to “release” as intended … thereby using much more HP than intended. As in previous post, even when the clutch releases as intended, it uses HP. Although there’s PLENTY of room under their hoods … ALL, repeat all nascar cup-busch-trucks use electric exclusively. So does our circle track car.

Yes, it’s true that electric fans use some HP. But to disregard them in lieu of engine driven fans is false economy. So, dump your engine driven fan, install the dual fan setup and enjoy a small HP gain.
JACK:gap

 

[Vettehead Mikey]

I won't argue with your assumption of 85% electrical efficiency of an alternator , but you've forgotten another factor - the mechanical losses in transmission of mechanical energy from the engine to the alternator, and the frictional losses of the alternator itself.

My assumption of the 1 HP loss to the fan clutch included the mechanical loss within the pulley and drivebelt and additional frictional losses within the water pump over and above those of the water pump function..

Losses beyond these two factors for a clutch fan setup are related directly to the aerodynamical efficiencies of the fan blades themselves. If either the clutch fan is free wheeling, or the electrical fans are off, the characteristics of the fans are irrelevant.

I think if you look at total system efficiencies (engine drives alternator, which converts mechanical energy to electrical energy which is supplied to motors, which convert electrical energy back to mechanical) you'll see that the losses of that system are compounded and far more than the <1HP you calculate.

There again, everything I've said (which may make good common sense to some people) gets cancelled out because all, repeat ALL, Nascar cups busch trucks do it. I usually lose the discussion because somebody points out that you can buy the stuff from Summit or Jegs on the internet and THEY say it's good so it's GOT to be good.

Wanna buy some slightly used poly bushings?

 

[bossvette]

I use a Flexilite Black Max electric and an L-82 copper core radiator and don't have any overheating problems total cost @$400. I have enough horsepower that I don't have to quibble over 1 or 2 more or less
and yes I am putting the Ole boy on the dyno during Cruise-Fest 2004 :cool

 

[Robin7TFour]

Greetings, is there really ever ENOUGH horsepower?

ROBIN

 

[g046678]

BeCool

I've installed the BeCool radiator with the dual Spal fans. I have no complaints at all. I've taken out the shroud, and have much more room to work.

 

[Jack]

Don't lose sight of the fact that a street-driven vette must have an alternator (or gen) ... and its associated drive belts and pulleys (and their friction) ... all necessary regardless of fan type. Chevy gas motors' fan clutches ... when properly-working ... do not truly freewheel. When disengaged or released, a properly working fan clutch should not fully disengage and should not completely freewheel.

I have poly in front of my 71 ... much easier to install than rubber ... ride kinda stiff but just what I like ... if/when mine ever squeek I'll give em a little more lube. Over the long run, I would not rely solely upon the graphite in polygraphite to prevent squeeks.

I agree with your jegs-summit comment ... just because a claim's made doesn't make it so. I have no solid, direct cup or truck experience (although I've tinkered with a few). But busch gn is a different matter ... have direct, hands on, been there done that, got that t-shirt experience. Also co-own, wrench & campaign in nascar weekly touring series ... I do not drive.

It's pretty straight forward ... remove the engine driven fan off the front of just about any street car ... right away you'll feel more oomph ... it'll rev quicker. Add an electric fan and there'll be a small reduction of the gain. However, for overall long-term reliability the engine driven fan-fan clutch is 1'st pick.

Electric fans do fail ... pretty rare but it does happen ... I've seen several street car elec fans that locked up or the temp sensor failed. I got a rare, internal short inside fan motor on a supertruck ... cost us a badly-needed practice session for last November's race at Myrtle Beach Speedway.
JACK:gap

 

[BiggBrakefuelie]

I've installed the BeCool radiator with the dual Spal fans. I have no complaints at all. I've taken out the shroud, and have much more room to work.

I`m glad you have had good results with this kit.I am just in my first day with it and so far it`s pretty awsome.My car runs cooler than before and as you stated there is much more room in the front of the engine compartment.So far I have driven through traffic and open roads and it pretty hot here in Sacramento.The Vette hasn`t gone over 200 once.
As for HP.It`s a pretty interesting debate though I didn`t do it really for any big performance gain I was just told I might gain a little.I do like the Aluminum radiator.I would recommend this Be Cool kit for anyone with cooling issues.They tell me that it can cool Vettes over 700Hp. and up to 500-600 Cubes.

 

[photovette]

The HP gain is got to be greater than 1 or 2. When I have the a/c on and have to sit at a light, the fan clutch engages and performance off the line is considerably reduced (I have a 355/350hp). I noticed a big difference off the line (when hot) when I installed the electric fans. Just my observation.