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Does anyone here use a Flex Fan to improve your cooling? I'm trying to decide between a Flex Fan and custom shroud or an add-on electrical fan that only comes on when the engine temperature exceeds a designated point.
It gets really hot out here in the desert, and the engine gets pretty warm when climbing long graes.
Steve - SoCal
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posted by
someone claiming to be Erik
on
Fri Oct 22 03:03 CST 2004 [ RELATED]
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Flexlite 1313
It looks great, is metal and will not take 5hp to spin at high rpm like the heavy metal stock fan.
It will not work on a car with a double crankshaft, it hits it.
Let me know if you find anything else that fits.
Also, a three core radiator (3/8 tubes if I recall right?)will fit nicely without any modification.
-Erik
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Let me be the devil's advocate here. Before you start swapping or adding fans, I would suggest that you make sure that your radiator and other cooling system components are in tip-top shape. Furthermore, don't let that silly temp gauge scare you, they frequently indicate higher temperatures than are really there. Take some actual temperature readings on the coolant and/or block. (Lots of stuff on that in the BB archive) BTW, I've swapped two-bladed, for four-bladed, for five-bladed, and for six-bladed fans without any noticeable difference in temp gauge readings.
I drove Amazons in the tropics for decades; jungle, desert, mountains, you name it; and never had one boil on me, excxept when my radiator hose gave up the ghost, and then the only thing damaged was the temp gauge - the engine went on for another 100K miles or so before before it started to use a little oil. True, those were B16s, but I don't believe B18s or B20s are less happy at high temps. I would only mess with fans if, after I had had my radiator thoroughly cleaned, I could get the thing to actually boil, and than I would still think the problem might lie elsewhere - like tuning.
Bob S.
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OK, please allow me to elaborate:
The radiator is NEW, so there isn't any crud in it. Besides, I flushed it right after I bought the car and it's super clean in there.
I have a 4-bladed fan at the moment, and there is hardly any noticable 'twist' to the blades. It looks to me like someone was searching for free horsepower and decided the fan was pushing too much air.
I just removed a good add-on temperature gauge and re-installed a stock one. The old gauge generally read OK except when I was pulling a long, steep grade. the revs go down and the speed goes down, and the temp goes up.
No, it hasn't actually boiled on me yet, although I found the overflow tank empty and had to add all my emergency drinking water to get it to the proper level. Looking at it today, I think I will have to add a little more water before I go anywhere very far from home.
The fan that's on it measures 11 inches, with plenty of space left over, so a 13 inch fan will do nicely. I may have to add a 1 inch spacer to clear the belt, but that's no big deal.
I've run good quality flex fans on road cars and race cars forever, so I should be able to find one that will stand up to the task without exploding and throwing shrapnel into the works.
The ones to avoid are the old ones that used fiberglass blades. Good stainless steel blades are usually a sign of quality.
One factor that may be causing the car to run hotter than I like is that it still has the radiator from the B-18...or it may even be from a B-16.
Regardless, it is pretty small, has only two rows of tubes, and there is no shroud to channel the air effectively.
If I get the money, I'll have a four-row radiator built and quit fretting about the engine temp. :-)
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Yup. Four rows should do the trick, but make sure your pull-up blind is in good working order for those cool SoCal January nights ;-). But seriously, I had a two-blade fan develop a fatigue crack + wobble out in the middle of nowhere between Barquisimeto and Valencia in Venezuela, i.e., ambient temperatures well above 90. I removed the fan and drove about sixty miles on, what would here be considered, secondary, rural roads. The thing never boiled till I stopped to have the fan welded. But it is not just the efficiency of the cooling system, it's also a matter of how much heat punishment these engines can take. When I had that coolant loss I mentioned in my earlier reply, the engine got so hot that large blotches of the paint turned brown and in some places actually burned off. Not only was it still running after I taped up the hose and refilled with water, when I had the engine checked at a Volvo shop they couldn't find anything that needed attention besides an oil change , a new set of hoses and a new temp gauge. They did a tune-up for the sake of our mutual morale.
Bob S.
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"Pull Up Blind?" Like THAT would still be in place on a California car!
I've been looking for a good one at a reasonable price, though, because I do like to drive up to Lake Tahoe in the winter. The last one I saw was only $20 but it needed new fabric.
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I agree with Bob on all counts.
Fact is, if you're going over 10 mph, the fan basically does nothing but add drag and make noise. A flex fan, with it's coarse pitch at low rpm, can help keep things cooler at idle when stuck in traffic, but that's about the only benefit.
Condition of the radiator and rest of the cooling system is a lot more important than the fan, and tuning has a real impact as well. I don't even have a fan at all on my hot-rod B20 (except for an electric one that never comes on if the car ismoving at all, even on the hottest days), and it never gets overheated at all.
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I'll thrid on to this bandwagon. If the car overheats at a standstill or moving slowly, it is (likely) an airflow problem. If it overheats moving it is a coolant flow problem (pinced hose, sticking thermostat, plugged radiator, etc).
I have a thermo controlled electric fan on mine which will only ever come on on a warm day when the car sits still for several minutes.
--
I'm JohnMc, and I approved this message.
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I've heard that the flex fans have a nasy habit of cracking and flinging the broken parts in bad places.
For extra performance I like the electric ones.
--
'96 965 with 16' wheels at 120K. Had '85 745 Turbo Diesel for 200K.
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The fans with the aluminum blades were notorius for throwing sharp pieces of metal around.
The stanless steel ones seem to hold up well, I've never had a problem with one.
Funny, I can get either a flex fan or a 12" electric fan for about the same price. About $30...
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