Team Camaro Tech banner
1 - 20 of 25 Posts

·
Registered
Joined
·
424 Posts
Discussion Starter · #1 ·
Gentlemen.......i just put a z/28 clutch fan on my 69 camaro rs/ss...i took off a flex fan.
which uses MORE HP to run the flex fan or the clutch fan??
did i do the right thing?
 

·
Registered
Joined
·
77 Posts
If the clutch fan is working right it would be the best choise.
I have seen on a dyno that a clutch fan uses less HP that a flex fan .
And I read somewhere about a comparison on them. The clutch fan won every time.
 

·
Registered
Joined
·
2,664 Posts
The clutch fan uses less power but they also go out at the most inopportune time. If your luck is better than mine use it. I have noticed that my Nova cools better with a flex fan but they are notorious over heaters.
 

·
Registered
Joined
·
424 Posts
Discussion Starter · #4 ·
thanks guys....thats what i needed to hear!

Gotta love camaro"s!
 

·
Registered
Joined
·
312 Posts
IMHO i like electric fan's. the most power for the cooling.

also a flex fan can cause premature whearing out of a water pump. a clutch fam is nicer to the water pump. but any motor mounted fan causes undo stress on the water pump shaft from the load and vibration. no fan motor mounted is vibration free.

haveing your belt's too tight also causes undo stress on the water pump shaft.

with a electric fan you get the most HP to the wheel's and your performance and fuel econamy will go up. your water pump will last longer too. most pump's fail from stress realted bearing whear and seal's failing because of this. with out a fan on the pump shaft this basical go's away, unless you have your belt's too tight.
 

·
Registered
Joined
·
2,664 Posts
Ok why is a flex fan harder on waterpump bearings. A clutch fan is definately heavier and the greatest mass is forward of the fan {farthest from the bearing} sure it doesn't turn all the time. But the less weight and shorter distance to it should reduce the load on the bearing. You are right about electric fans at one time they were unreliable but the new ones work wery good. And it takes no HP to run one.
 

·
Premium Member
Joined
·
2,118 Posts
I have a thermal clutch on mine but want to know if any of you have installed an electric fan inside the original fan shroud. It could look original at first sight if it fits inside. Have any of you done it? Which size or brand? Just thinking for a future proyect.
 

·
Registered
Joined
·
170 Posts
There is a article on this subj in a fairly recent issue of car craft, sometime over the summer i think..they did the tests...the clutch fan came out way better hp wise than anything except the electric.
 

·
Registered
Joined
·
195 Posts
To answer the question....about 12-16 HP.

This is realitive to a fan and clutch, as compared to no fan/clutch at all.

Yet an electric will also eat up some power too. Alternator loading will cost you very little, but it does take some...maybe 3-4 HP.

Circle Track Magizine just did a great article on cooling system parts. (the issue dedacated to Dale E.) It explains it, how and why......
 

·
Registered
Joined
·
2,664 Posts
ORENCH I had to put one on my Nova when I put air on it just get a real narrow one. My 79 vette came with an electic fan in front of the clutch fan.
 

·
Registered
Joined
·
312 Posts
oger,

the clutch fan set up isolate's the pump shaft from vibration and since a clutch fan never totaly lock's up the stress from driving a fan all the time is not there. the clutch is a viscus type clutch. it uses a silicone fluid that is very thick. it work's kinda like a tourque converter. the fluid is what transfer's the power, it also absorb's some of the load and vibration.

this is why the general went ot a clutch fan, less stress on the water pump and more power to the rear wheel's. now most new vehical's are going to electric fan's. they get more power to the rear wheel's and the alow the motor to work less to do the same thing cause they are not as much of a load on them. light truck's are going this way too. the motor mounted fan is going the way of the carburator on new car's people.

oh and oger just go to a clutch fan manufature's web site. you will get the same info i posted. allso i belive the car craft artical covered this too. i belive supper chevy did a artical on this too.



[This message has been edited by ilbl8 (edited 04-18-2001).]
 

·
Registered
Joined
·
424 Posts
Discussion Starter · #13 ·
Thanks ilbl8.....that was a good explanation.

Hey Chacane67.....could you be a little more clear on your 12 to 16 HP explanation.
is there a 12 to 16 hp diff. between a flex fan and a clutch fan?
 

·
Registered
Joined
·
312 Posts
i think he ment between any motor driven fan and an electric fan.

some maker's claim up too a 40 HP differance, but i have seen chasie dyno's give 12 to 20 HP more with an electric over a motor mounted fan.

i belive there is a great diferacne between flex fan's and clutch fan's just do not have any #'s. all the expert's say a clutch fan is the best of all the motor driven fan's, they take less HP to run and add less stress to the water pump.

the 3 to 5 HP for an electric fan i do not know about. most electric fan's take up to 30 amp's at start-up then drop to around 10 to 15 amp's when runing.

some monster OEM dual electric fan's take up to 60 amp's starting up and 30 amp's runing.

i personaly belive that the impact on the motor is almost not mesurable, as an alt is going to be running anyway. and if it is 3 to 5 HP that is not gona impact you any, heck you would never be able to feel the power loss, and as for the impact on speed and stuff that is basicaly not there at 3 to 5 HP.
 

·
Registered
Joined
·
424 Posts
Discussion Starter · #15 ·
Thanks ilbl8
 

·
Registered
Joined
·
312 Posts
here is a pic of my electric fan. i had the shroud made at a loacal sheet metal shop. you do not want to mount the fan on the radiator core. the core was not ment to take the weight or stress from the fan! all so you need about 1" to 2" clearance from the core so the fan will not stall out. no maker's tell you this, i do not know why. the shroud is a mont and it also help's the fan draw air from all over the radiator core. this is very important to the cooling of the radiator. well here ya go.
http://y42.photos.yahoo.com/bc/ilbl8/vwp?.dir=/car+stuff&.src=ph&.dnm=fan.JPG&.view=t&.done=http%3a//y42.photos.yahoo.com/bc/ilbl8/lst%3f%26.dir=/car%2bstuff%26.src=ph%26.view=t
 

·
Registered
Joined
·
2,664 Posts
ilbl8 the car manufacturers went from clutch fans to flex fans a long time ago they went back when gas mileage became the ultimate goal. If you believe what someone says about there own product you are going to get screwed alot. I have never lost a waterpump bearing with a flex fan but I blew the whole front off of a waterpump with a clutch fan.
 

·
Registered
Joined
·
2,729 Posts
The reason the OEM's use an electric fan vs. a mechanical has to do with the design of the car, not the performance of the fan system.

With the frontal designs of modern automobiles it is not practical to use a belt driven fan.

Trucks still use belt driven fans. The belt driven fan has significantly more cooling capability and the current frontal designs reflect it.

Tom was referring to the difference between a flex/fixed fan and a clutch driven fan. A flex fan can require up to 20 hp at full engine RPM. A properly operating cluch fan will take less than 5 and do a better job. Electric fans do draw horsepower. You can't get free energy.


------------------
New! Vintage 45's and a homemade cowl induction air cleaner. http://www.geocities.com/casanoc
 

·
Registered
Joined
·
312 Posts
true but the draw is alot less then a motor mounted fan. as for the truck's, in the next 5 year's all most all light truck's will have electric fan's, just watch.

by the way oger, OEM's used flex fan's and fixed blade but droped them for the clutch fan. the OEM flex fan was not as flexable as the after market one's. this was so they would not do a bomb burst at high RPM. they used the clutch fan on A/C car's only for a # of year's, all so for a long time only A/C car's got a full fan shroud. all that changed when under hood temp's took a big jump in the early '70's with the advent of emmision's stuff, so all car's got the clutch fan and full fan shroud as it was more efciant over all.

the switch to electric was also cost, they are cheeper to make and install too for the OEM. there are alot of thing's behind it. but ultimitly it is to get that last MPG out of the car.

true the advent of front wheel drive is what realy fueled the electric fan change, but that was just one of the factor's.

most light truck's and SUV's are not used as tow vehical's or carry large load's. they are used like a car. that is all so why you will see them get electric fan's, as the fed's start wanting more MPG out of this class the OEM's will do this.

[This message has been edited by ilbl8 (edited 04-19-2001).]
 

·
Registered
Joined
·
2,664 Posts
ilbl8 my 63 FI my 65 L78 my 66 L72 Vettes all had fan shrouds and clutch fans. I guarantee you air conditioning was not an option on any of them.
 
1 - 20 of 25 Posts
Top