Anyone have input on this? I have an old flex fan that I am going to replace.. Searching tells me flex fans rob you of HP. I am running a blower so staying cool is a big deal. Any advice? Looking to place an order today. Here is a link (oh, I am not going electric)
http://www.speedwaymotors.com/search...first_answer=1

 

If you have room, your best bet would be to use the stock clutch fan.

 

In addition to using a stock-type fan clutch, which is very effective and reduces horsepower losses, use a stock fan, too. Most of the aftermarket fans, including the Flex Fans, have hollow-core aluminum rivets in the blades, making them extremely dangerous at high rpm: I've seen them shell blades, and the damage is amazing (not to mention what it would do if the blade went thorugh your head while you were setting the timing). If you go aftermarket on the fan, check the rivet type and quality.

I saw some dyno results run by my favorite local engine dyno operator & NASCAR builder on engine fans. The stock fan/thermal clutch setup was by far the most effective, with minimal horsepower loss under operating conditions. Electric fans actually consume more horsepower from the engine than a straight mechanical clutch fan when they're running - there's no free lunch.

Lars

 

An electric fan/shroud out of an early 90's v6 Tarus along with a fan control switch from Summit works great and gives you more room under the hood. You can scrap that honking factory shroud... I have been running that set up for several years without any issues. You can run a two controlers and use both speeds of the fan. The whole set up costs about 200 bucks. You will need to do some 'Stylin and Smithin' but it's nothing over the top...

 

Good choice. Stock fan and clutch is your best bet.

 

Flex-o-lite fit perfect but you have to install a good high amp alternator. If you don't have A/C you can use them as pusher fans. They almost look factory!

 

Doesn't anyone read the posts before responding any more?

 

I read it... just trying to help. I even have my original fan and clutch for sale, in excellent condition, if your looking for the right stuff. I can send you a picture and we can work out numbers. Send me a private message and I can get that too you.

My point being, unless your goal is a factory look and keeping it original, there is no reason to live in the past and updating your car so it is safer and more relyable is not a sin.

I was beginning my career as a professional car mechanic in the late 70's and cut my teeth on cars like this. They were as good as they could be given the circumstances, but they overheat, always have and this chassis never dealt well with the reality of wanting the L82 in the dead zone, transition cars from that era... and like I said on other threads, it's amazing that that these cars even exist at all... people forget.

Didn't mean to pee you off, I was just trying to answer your question.

 

These use a ton less power than the old steel flex fans do are quieter and dont come apart. Only weigh a few oz and you wont have extra weight hanging off the WP.
Like others have had..had a steel blade come off at idle while I was under the hood, another came apart sitting in the car revving it. That could kill ya

Probably stick one of these back on this summer and keep the electric as a fail safe "just in case". Have 2 they are super old..cause they dont break lol.


http://www.summitracing.com/search/?...on%20fan&dds=1

know a lot of imports used a clutch fan with those white nylon type fans too bad GM doesnt have something like that. Seems like a perfect compromise.

 

yes I read it. I'm just showing its a good option for less than $400

 

I am really interested in replacing my clutch/fan combo on my 81. I have read where you don't need the clutch with some of those lighter fans.

I will definitely be running my air conditioner and want to increase cooling.

It seems to me that more fan blades, lighter fan, should work better. My car already has an electric fan thermostatically controlled from the factory.

So it seems to me, but I could be wrong, that the lighter fan running all the off the w/p would be an improvement.

Again, anyone running these, and feedback please.

 

You don't want to direct drive the fan. That's when the blades start coming off, in a bad way.

 

It depends on the fan

One i listed in the link will take 6800-7000 rpm all day long.
All the guys used them nobody ever had a failure
Used to use them on circle track cars, they would last indefinitely
}The metal ones are dangerous imo

 

Obviously not. The OP might have had better luck had he specified 'electric fans only'

 

If they use a ton less power then they move a ton less air.

I'll bet they're not as old as my stock fan and clutch, which also hasn't broken.

 

Bet the water pump bearings last much longer with the ligher piece.
Think about it, oz vs how many pds? Those clutch assy with fans are heavy!

If you like stock stuff thats your business.

All I can say is Ive NEVER had a heat or breakage issue with one of those .They are cheap, safe and do the job. When it comes to reliability "stock" to me plays nowhere in the equation unless its better.

Maybe rpm has something to do with it. Being one that likes to twist motors up the lighter piece works for me. Had too many WP go bad using the heavier pieces on them. yes they cooled Ok but got tired of buying pumps.

Going to go out on a limb and say that plastic fan will move more air than the 2200 cfm spal I have on theri now. Find out soon lol.
To each their own.

 

IDK, I bought my car in '79. The engine had been replaced under warranty sometime in 1970, so I don't know if it was the original water pump or not. I replaced that engine in 2005, it still had the same water pump on it. The original fan and clutch is now on my big block.

 

The reason that the fan clutch is on these cars in the first is that the fan is only efficient up to about 30 mph. The staggered 5 blade configuration is a little better, but not much. (The blade is staggered for noise reduction).

Belt driven plastic fans flatten as they spin, this reduces radial drag but they actually become an air dam hindering air flow at speed. The trade off being a reduction in spun weight. Air flow is everything for these old beasts. That is why the original design was wrought with seals, shrouds, dams, etc. Car manufacturers study stuff like this extensively. Aside from the fact that most modern cars have transverse engines and can not drive a fan mechanically, you simply will not find engine driven fans in the wild anymore.

That said, after a fan hits and then surpasses it's max efficiency, it becomes spun weight just along for the ride. The viscus clutch allows the fan to free wheel and coast as needed. I believe this is called the 'Flintstone effect'. I suggest a fan made of Cavemanieum...

They cost three clam shells at Bedrock Auto.

 

Did anyone mention the stock setup? I like the AC steel fans, I think they are 7 blade? My 68 L36 runs cool in hot Silicon Valley all the time. Just my experience...

 

Stock clutch fans work great on stock cars but when they get hot there is a lot of parasitic drag to turn those blade. I've had a Fiberglas fan blow apart on me years ago, I don't even think they're made anymore and the alum fans usually have sharp edges I never liked but the dual electric had an emediate difference in the throttle response , saved gas, keeped the engine cool, made the front of the engine easy to work on, ect...
The new electric motors made the difference from years ago . They have smaller size, less amperage, better blade design and more CFM than the stock fan.
It's a win/win IMHO