ok ..i have heard the debate for a long time now...and today someone argued the point once more,.. 1. Flex fan is good to move air at slow engine speeds and flattens out when the engine is going so that it doesnt use HP..... 2. Steel fan is great at all rpm ranges...but is large and heavy and used HP to use... is a flex fan or steel fan better.. i am still having the cooling probs and a guy that i now said the the steel fan will solve the prob for sure...but people have said that the steel fan puts a lot of stress on the motor and it is SUPER loud.... who is right... now i know i am going to get a lot of opinions....i just want to know...from those that have used the steel fan and flex fan on the same car...what was the difference... thanks
Well, I have never used a flex fan and have heard some bad things about them comeing apart. I have had several diffrent steel fans on my Mav though. I replaced my original 4 blade fan with a 5 blade truck fan from my '68 F100 parts truck. It cooled better but the diffrence was VERY noticeable. It definately slowed the car down some. A couple of months later I replaced the 5 blade truck fan with a stock 6 blade Maverick fan and imediately noticed a power increase and better cooling. So, in my experience, how big around the fan is has more to do with it then anything. Thats just what I have found though.
My '73 with 302 came stock with a flex-fan. I think that the flex-fan is the way to go. I also think that the stock flex-fan cools better than aftermarket flex-fans. The only other effective alternative I can think of would be an electric fan...
I have a 1300 series Flex a Lite on mine. Not noisy at all and rated to 10,000 rpm. Works good without a shroud but would definitely work better with a shroud. I say get the flex fan. They also have the 1800 series which is a 7 blade unequal spaced fan for quiet operation.
I have a 5 blade flex fan, and have no complaints, except that it cuts my knuckles every time I open the hood (the fiberglass shroud disintegrated the first time I touched it). I am currently looking in the junkyards for a slim electric fan. I want to free up the horsepower, and 2ndly, I have had two people tell me (in less than a week) that getting rid of the flex fan is a good idea, as they have both lost friends due to the fan breaking apart while manually revving the engine at the carb, and having the fan blades fly off and kill them. So, freed-up horsepower, less cut knuckles, better cooling, and staying alive...options that an electric fan offers over the steel fans.
I like flex fans myself. I've only seen 1 come apart and that was in about 1977 or 78. It was on a K-code 289 in 66 Mustang that had been built up and raced hard. And when it came apart it was not pretty. Through the hood and all. Also seems they don't work well on trucks pulling campers and in performance cars with high stall converters driven in the city most of the time in stop and go traffic. Like all parts, buy quality. Flex fans start at about $16 for a China made import and go up to about $70 for a 10,000 RPM Flex-a-lite. So which ones do you think might be prone to coming apart? :evilsmile
How does the unequal spacing make it quieter, and not rattle around? Are the blades different shape/weight for balance? How much HP do they eat, compared to my stock 5 blade?
I am presently running a flex fan on my car but will be going to a steel fan just to test out this theory. A flex fan supposedly robs horspower. A steel fan with a fan clutch is the way to go, or at least I have been told by a local high performance shop here. The fan clutch will allow the fan to freewheel at highway speeds saving fuel and horsepower. Your fans are useless on the highway. The clutch will make the fan turn full force only when it is needed, at slower speeds. The clutch is the key to this entire process here. I already have my new clutch. I just need to go through my steel fan collection and see what will fit best. If it does in fact work better I'll let you guys know. Don't hold your breath though, it may be 3-4 weeks before I have time to tackle this.
That doesn't sound right. The whole idea behind a flex fan is to reduce the drag of a fixed pitch blade at highway speeds. Flex companies have been marketing the HP gains for decades. I've never read one thing that says it robs power....... Fan clutches do the same thing, but besides RPM, they also are "smart" to the temperature of the air moving past them and will adjust fan speed accordingly. They do this through viscosity of a fluid filled clutch or by electromagnets. They were designed for severe duty like trucks or big "Caddy" size cars. They work great until they break at which time they either lock up all the time and cause major drag (and tons of noise) or they slip all the time and cause over heating in city traffic. Blades are still balanced but spaced out unevenly, which makes them sound quieter to our hearing by spacing out the pressure waves.
I have had 2 fans on my Stallion,, the stock fan just wouldnt cool the motor that is in it now. I went to a big flex fan in 93. Has not had any cooling problems since. Clutch fans are great also, and have used good ones on other makes with success. Dan
Are all cheese-heads as smart as you, Eric? You always seem to have obscure knowledge about obscure 'things'. Don't ever leave us!
I've been tossing around the idea of a clutch for a while now. I'll be waiting to hear what you have to say before I go junkyardin', Ray. Any little bit of power you can gain with these little 6's always helps.
Just buy an electric fan, then you don't have to worry if a flex or solid fan is better. An electric only runs when you need it, and then it runs at full speed regardless of your motor's rpm, even at idle.
