GM 7 blade fan vs Metal flexalite fan. Whats the better buy [Archive] - Team Camaro Tech

: GM 7 blade fan vs Metal flexalite fan. Whats the better buy


life4christt
Jan 15th, 08, 03:41 PM
I got ahold of the GM dealer and they can get a 19in 7 blade fan for $ 76.00 and summit has flexalite 19in 6 blade fan for 26.95 . Is the gm 7 blade worth the extra 50 bucks or is there even a better buy then these. I just want the best bang for my little bucks.

Mark C
Jan 15th, 08, 04:33 PM
19" blade won't fit in an 18" stock radiator shroud. Incase you have a stock setup.

Flexalite fans don't move near the air a GM fan moves.

1969ProStreetCamaro
Jan 15th, 08, 05:48 PM
I've got a Flexalite fan on my 69 with a 468 and have no cooling issues whatever. 468 idles in traffic at 185 all day long with the Flexalite fan.

hhott71
Jan 16th, 08, 08:49 AM
stock clutch fans out perform in cooling and less HP drag than flex fans.

If flexfans were better, wouldn't the car companies installed them in the first place? They are sure cheaper to make.

BlackoutSteve
Jan 16th, 08, 11:00 AM
Flex fans..
Why spend your horsepower flexing blades when they should be moving air?

life4christt
Jan 16th, 08, 08:20 PM
Does autozone or kragen stock 7 blade gm fans?

Eric Kammerer
Jan 17th, 08, 06:11 AM
No. But they would likely carry the thermostatic fan clutch that you need with the GM fan; it cannot be used without the clutch. And the clutch is another $50 or so.

If you want to run a flex fan because you don't want to spend $130 or so on the GM fan and clutch, that's okay. Just measure and get what you need, and make sure you get a fan spacer to properly position the fan in the shroud (you can't just bolt the $26 flex fan to the water pump pulley and call it good...).

Eric Kammerer
Jan 17th, 08, 06:25 AM
Or keep watching ebay...

http://cgi.ebay.com/ebaymotors/1970-chevelle-clutch-fan-396-454-malibu-ss-z28-camaro_W0QQcmdZViewItemQQcategoryZ33600QQihZ014QQi temZ330204226170QQrdZ1QQsspagenameZWDVW

Eric Kammerer
Jan 17th, 08, 06:37 AM
Here's info on what your 70 had on it originally.

http://www.nastyz28.com/2gcog/cooling.html

I see you're running a 400 SBC; I would want to make sure any 400 is very well cooled.

hhott71
Jan 17th, 08, 07:33 AM
Does autozone or kragen stock 7 blade gm fans?
GM does sell the fans. Be friendly with the parts dept, the discounts and their resources are invaluable over the many years of car addiction.

Farm Boy
Jan 17th, 08, 08:53 AM
I used a Hayden #2707 thermostatic fan clutch with a Hayden #3618 six blade fan in my 67. The whole setup is available from partsamerica.com (http://www.partsamerica.com/productdetail.aspx?MfrCode=HAD&MfrPartNumber=2707) (Kragen) for about $60.

http://geocities.com/sdampier@sbcglobal.net/Team_Camaro/fan-016.jpg

Eric Kammerer
Jan 17th, 08, 09:00 AM
The Hayden standard duty fan clutch for 70 Camaro (long water pump) is #2705. If you have a short water pump, you can use the number Steve posted.

life4christt
Jan 19th, 08, 11:30 PM
what is the difference between thermostatic fan clutch and non thermostatic fan clutch?

BlackoutSteve
Jan 20th, 08, 02:47 AM
The non-thermostatic clutch hubs are rpm activated, and found mainly in light trucks.
You're better off with the OE thermostatic type. :thumbsup:

JimM
Jan 20th, 08, 06:08 AM
On the flex fan thing, the ability of the blades to flex and flatten at higher rpms causes them to consume LESS power (at higher rpm) than a fixed blade fan that can move the same amount of air at idle speed.

Of course at least in theory, the clutch in the clutch fan does the same thing.

I've heard that the flex-a-lite fans, at least the cheaper ones, were less than good.

I've used a 17" Derale flex fan for many years. It works really well for me. It keeps the motor cool and it's quiet, and it has held up very well. Cost was just less than $50 I think.

life4christt
Jan 20th, 08, 07:48 AM
I just went to the junkyard and found a 7 blade fan and a fan shroud for $37.00 Now I am going to order the cluth for the fan so by the end of the week I should have everything I need. I will let you all know what the outcome is.:hurray:

BlackoutSteve
Jan 20th, 08, 11:14 AM
On the flex fan thing, the ability of the blades to flex and flatten at higher rpms causes them to consume LESS power (at higher rpm) than a fixed blade fan that can move the same amount of air at idle speed.

It still takes energy to bend the blades of a flex fan for little air-flow in return, -probably when you need it most..

Imagine being on a chassis dyno or just doing a good ol' burnout with your car stationary, engine revving and that flex fan doing nothing but flexing while your making at that heat.

I honestly think they're a scam!

Clutch hubs will lock up and move air always when needed.

life4christt
Jan 20th, 08, 05:51 PM
It still takes energy to bend the blades of a flex fan for little air-flow in return, -probably when you need it most..

Imagine being on a chassis dyno or just doing a good ol' burnout with your car stationary, engine revving and that flex fan doing nothing but flexing while your making at that heat.

I honestly think they're a scam!

Clutch hubs will lock up and move air always when needed.


I believe ya. Thats why I am getting the stoc 7 blade fan setup.

JimM
Jan 20th, 08, 05:59 PM
Clutch hubs will lock up and move air always when needed.
Judging from the obvious difference in sound from a just started cold vehicle with a factory clutch fan, and that same vehicle 2 minutes after startng and all other times until the next cold start, I have my doubts.

Our last 5 new trucks, model years 96 thru 2004, 2 GM, 2 Jeep, and a dodge... The only time that clutch fan is locked tight and moving max air is a stone cold start, when you don't need it. After 2 minutes, the fan becomes silent and stays that way, the roar of moving air is gone.

"Stationary on a dyno" simply is not a design criteria for an automotive cooling system. Dyno shops have great big stationary fans they use to keep the cars cool.

And I really don't mean to debate this, just put out some facts. Factory style clutch fans are indeed very effective coolers. So is a well designed quality flex fan.

BlackoutSteve
Jan 20th, 08, 10:52 PM
Judging from the obvious difference in sound from a just started cold vehicle with a factory clutch fan, and that same vehicle 2 minutes after startng and all other times until the next cold start, I have my doubts..

When the viscous fluid in the clutch hub is cold, it will turn the fan as if locked. Once the fluid heats up, it will allow slippage and then lock and release as normal. ;)

I can definitely feel the hub lock up in my old beater. Sitting in traffic or surprisingly at freeway speeds. (I think that car had airflow issues, but the fan was working well. It never over-heated.)

Ever cut one open? Very interesting..

life4christt
Feb 16th, 08, 08:02 PM
Car runs fantastic and never goes above 175. Thank you all for your help:beers: