Which flex fan should I order?

[muddermilitia]

With the new location of my Orbital valve (for full hydro steering) and where the hoses go, it doesn't look like I can run the original fan. SO I was just going to order a flex fan in a smaller diameter. 16" looks like what I will be able to get away with. Looking on Summit, I see a couple 16" fans made of Nylon and 1 made of steel.

Will the Nylon hold up to offroad use? Or will it break the first time I hit a water hole? The steel fan is offered in clockwise and counter-clockwise rotation, I would need clockwise correct? This is for the Trazer in my sig. Bone stock 89 350 TBI motor. Yes, I know I should put windstar fans on it, but I'm just trying to get this thing ready to wheel by July.

These are the two fans i was looking at:

http://www.summitracing.com/parts/flx-416/overview/

http://www.summitracing.com/parts/flx-1316/overview/

Last option: Should I just cut down the stock fan? I have never had overheating problems with this truck, but then again, most of it's offroading experiences have been under 20mph. Just don't want to run into any problems when I'm at the Dunes.

Thanks

 

[diesel4me]

It would not be possible to cut down a fan blade and ever get it to balance properly....(unless you had all the right equipment maybe)...

I'd just search the boneyards for a mechanical fan that has the proper pitch for whatever rotation you need in a smaller diameter ,myself...or go electric and get it over with--it may not take as long as you think to convert it by the time you find and install a mechanical fan that may not end up cooling it enough..the fan needs to be close to the shroud's diameter and "in" it about 1/3rd in order to pull air thru the radiator well..

I learned not to ever use a fan spacer with a clutch type fan too--ended up shearing off the water pump shaft flush with the pump,which allowed the blade to impale itself in my radiator core,and shear the upper hose nipple almost completely off....I revved the engine up when I was hung up in snowbank while plowing...wasn't a fun day,I had only made one pass and had not yet reached the street...had a long day & right searching for parts and repairing the truck...

 

[Greg Ducato]

Good advice Robert, I would add that low speeds are the most crucial time for airflow created by the fan and shroud.

 

[496truck]

89 is a serp belt motor isn't it? If so, that would make it reverse rotation. If the pulley rides on the inside of the belt, standard rotation. If it rides on the backside of the belt, reverse rotation.

I don't really have any other advice to give except the electric fan thing, but you already covered that. FWIW, I love my e-fan swap. And it can be done for minimal cost compared to buying a new fan blade. And I used a Volvo fan instead of W-stars.

 

[muddermilitia]

Yes it is a serpentine setup and now that I think about it, I do remember reading about reverse rotation water pumps a long time ago when I replaced mine. As for the electric fan setup, I understand what you all are saying. I have the windstar fans already sitting in my basement. It's just that I'm running low on time and still have a whole bunch of other project to tackle. Plus the fact that the truck is an hour away from me doesn't help the situation. Just looking for something to buy, bolt on, and be done.

 

[76zimmer]

Water crossing and flex fans = gouged radiator

I use the dual Wstars and as long as I remember to turn them on all is good
Be sure to use waterproof relays and turn them off for water fun

 

[Bowtie85]

I cut the clutch fan down on my Beaumont.....3 years ago and no issues. Although I only nipped the corners off a bit.

 

[NorCal_Chris]

My flex fan exploded on the freeway in my blazer. Pit 6 holes in the radiator and took out the lower hose. I went to a stock fan


Apparently that isn't an uncommon thing with them either.

 

[Deuling]

Flex fans suck

 

[F-ingrob]

not a fan of flex fans i like the clutch fans if you check them for play when ever you service your rig you safe with them

 

[diesel4me]

My only experience with a flex fan was one I bought for 5 bucks at a swap meet--it had only 2 blades,looked like an airplane propeller --I installed it on my 72 K5's 350 and it appeared to me it had plenty of clearance between the v-belts and the blades,but the first time I revved it up to about 4500 rpm to pass someone,it "flexed" enough to chop the altenator and P
S belts to ribbons in about .5 milliseconds.....luckily I was not far from home so I was able to get it there without it overheating..

I went back to the stock mechanical fan after I replaced the belts..

I had the stock fan on my 1956 Chevy 3200 truck decide to chuck a blade when I was getting on a highway and I had it pegged in second gear...I heard a loud BANG and saw the hood jump up,I thought a rod came thru the block and hit the hood!..then I saw steam,and the truck was shaking like the engine was falling off its mounts...

I quickly parked it in the breakdown lane--when I shut it off and opened the hood,I heard the fan blade fall back into the engine compartment..it had made a huge gash in the hood about 6" long,and the hood on that truck was twice as thick as a 70's truck hood was!..it had also gashed the upper radiator hose and caved in the hose nipple on the radiator..

I figured I was going to have to walk to a phone and call a tow truck,but another motorist pulled up behind me--he looked at the carnage and said "eh--you can make it home 4 miles from here--he reached in and grabbed the blade on the fan opposite the one that broke off,forced it back and forth till it snapped off,and he said "start it up"..I did,and it ran smooth as glass again!..he had a gallon of coolant he let me have,and I limped home and went about fixing the radiator and upper hose...I ran the 2 bladed fan a day or two till I found another one to put on it!..

I know a guy my older brother worked with that died after a fiberglass fan on a Lincoln broke while he was using a timing light to set the timing,back in the 70's...the factory specs said to check timing at idle and at 3500 rpms..the fan blades nearly decapitated the poor guy,he died a few days later in the ICU..