cooling system

i am trying to find the answer to this question:
which is better for a high performance street big block buick, a clutch fan,or a flex fan? i have a 19'' stainless flex fan,and 2"spacer,i was told to go back to a stock style fan clutch system
seems to me that the closer the fan is to the radiator,the better the cooling is can anyone help me?
i also have a heavy duty 4 row radiator,and am making all air go straight to the radiator.
car is a 1984 le sabre 4 door,
engine: 1968 430(.030 over=435 ci)500 hp :3gears: :jd:

 

actually not really overheating, 195 on highway,200-205 in town. 195 t-stat,i also have an electric auxiliary fan i can add as well engine has 186 miles on it, all new parts

 

Over the years I have went back and forth from clutch fan to flex, the flex alway did better on my car, seems to draw more air at low speeds.
I even put one on my 88' caprice, its helped airflow across the AC condenser thus cooler AC sitting in traffic.

 

I have always heard to stay away from flex fans. I agree that the blades half in and half out is perfect location. If the shroud is air tight, then you will be getting flow through the entire radiator, not just in front of the blades if you are too close. I also agree to run a 180 degree T-stat. These motors love to be cool. It kind of goes with the koolness of having a Buick... (LOL)

:TU:

Mike

 

Its part of a package. As long as you don't use the wrong clutch, and you have a good shroud, I recommend the clutch fan.

One time when I didn't have a shroud, I "stacked" two 17-inch flex fans- one fan bolted directly to the water pump flange, then a 3" spacer, then a second fan. Having two fans like this simulated a shroud, and pulled mega-airflow to boot. In fact that setup pulled so much air at idle, that I could not pour water into the radiator without the water being sucked all over the engine!

The cooling system is one of those things that I would leave alone (especially this time of year) until a problem rears its head.

As a counterpoint to the comments about a 180-degree T-stat, I prefer to stick with a 195-degree T-stat for regularly driven cars. The oil gets hotter (and burns off volatiles & moisture), and you get a more efficient & complete combustion (cleaner emmissions, better gas mileage, etc.). The downsides are that at WOT you are slightly more prone to detonation, and you get a slightly worse volumetric efficiency. It depends how you drive the car. If the car is strip-only, then throw a 160-degree t-stat in there.

In my daily-driven EFI 455, I have a 160 degree T-stat that actually settles out around 175 degrees on the highway (depending on ambient temp). On my old 250I6 Special, I used a 195 degree T-stat because performance was a non-issue and the engine ran better hotter.

By the way, when I drive my 455 to work (about 50 miles each way on the highway), the electric fans never come on, even on 90 degree days. When the car is moving, there should be more than sufficient airflow to cool just about any engine. Really the only time you should need a fan is when you are idling or driving slowly, since the vehicle doesn't create enough airflow on its own.

-Bob Cunningham

 

flex fans use alot of h/p, also the rivets will come loose over time and you can throw a blade, it happen to me and it was not preaty!! they are also noisey, i think the only advantage is that they are cheap.

 

Well, a stock clutch type fan that is in poor condition will actually impede airflow, in my experience, on the highway

I have payed T-stat games and never seen a benefit to cooling efficiency. Some guys swear it helps them, it just has never worked for me.

The most overlooked part of the cooling system is the radiator cap. The way the system works, you need to be at a pressure higher than atmospheric to gain a higher boiling point. I know many coolant makers claim their coolant won't boil at temps higher than 212*F...well, that's good! because otherwise, it's water! :laugh:

The real boiling piont raiser is the pressure the system is kept at. many folks have malfunctioning rad caps and knock themselves out replacing pumps, fans, etc, and the problem was the 8 dollar radiator cap. A related and misunderstood system is the overflow, if your car is so equipped. Far from holding extra coolant, it's job is to allow the system to stay at higher than atmospheric pressure while also letting the coolant "overflow", because the radiator cannot expand to hold the higher volume of hot coolant. the overflow lets the radiator "purge" and "draw" ( as the rad cap moves) while keeping the feed/supply hose under the level of coolant, and thus higher than ambient pressure. If it's too low, you'll draw air at atmospheric pressure.

I used to have all sorts of overheating issues, I almost heat-seized my 350 in the winter one day. As long as I have a properly working fan clutch, the right shroud, a solid radiator with a working cap, and a working overflow, I have never overheated.

When I was a member of the Car and Driver forums (a dog eat dog place), I couldn't beleive how many folks I helped out of panicky overheating problems simply because I convinced them to replace the rad cap with a new, proper psi rated unit, and to check it before they installed

I know this is all a little outside of the discussion's scope, but cooling issues sometime seem like incredibly complex and frustrating things, and folks sometimes overlook the obvious solutions fixing them

 

I had the same problem, just ran a little hot, and noticed the burp tank was always low or empty, I changed the cap ,then it cooled down.

 

am going to napa,and get one specifically for the radiator i am using(76 electra)
the one i am using now is one is one form auto zone,for a 307 olds,which is what my car originally had. could this be my answer?? i prefer the safety lever type,are these ok?

 

yes they are O.K. they just dont look stock

 

what about Electric fans?

One thing I noticed with my heavy duty fan clutch is that the car sounds like a jet taking off, it does move the air but I think it robs a lot of HP.

One evening at the track, about half way down the track I threw the fan belt, and the car seemed to really take right off and rev right up.

I remember thinking is this fan really that hard to spin that I can feel the engine pick up when it is not being spun?

I am thinking it is time to move to an electric unit.
what is the general concensus on these?

Thanks
Joe

 

found the same fan clutch for a 3/4 ton chebby 454 truck thru auto zone for $57.99 !!
that's a $ 42.01 savings!! i may go buy it, is made by imperial

 

Airtex 2797TA ($62 from carparts.com)
Delco 15-4320
Everco A5570
4Seasons 36704 ($87, carparts.com)
Flex-a-lite 5649
Imperial 215045
Murray 271301
TRW FC 135
Hayden 2797 ($88, carparts.com)

 

The two most important parts to proper cooling are the pressure in the system and a proper shroud of some kind.

I like electric fans, but then you will likely have to fabricate a proper shroud.

If you have the money to burn, Be Cool has vehicle specific kits that include an aluminum radiator, billet catch can, and an electric fan/shroud combo. These sell for $1,000+...Check out Summit or Jeg's if you're curious. Really cool combo, but not at all stock appearing.

 

that's more $$$ than i have to spend!!
bought new napa radiator cap,and will see what it does

 

I have tried everything. My Stage 1 (.030 over) with the air on, on an 85 degree summer day won't stay cool untill I went to dual electric fans and an aluminum radiator. I tried the stock set up with pricy fan clutch, 7 blade fan and 4 core radiator but you can forget that set up in traffic with the air on.
Don't tell me about the good 15 lb cap and the 160 degree thermostat cause thats what I run.

 

i'm not running air,or heater