Flex Fan for '93 w/454 (?)
kalafre
02-22-2005, 09:26 AM
My '93 with the 454 motor has what appears to be a "heavy-duty" fan clutch. The clutch comes in during most conditions - it does fade out under light-throttle, but when the rpm's increase, the fan kicks back in. The temparature stays "normal" (ie: under 200) at all times. I know this is (to some extent) by design.
I am considering replacing the fan assy with a flex fan. I tow a 24' travel trailer and I don't know if this will work well when towing? Any thoughts?
I am considering replacing the fan assy with a flex fan. I tow a 24' travel trailer and I don't know if this will work well when towing? Any thoughts?
Larry Derouin
02-24-2005, 12:55 AM
The flex fan will turn at engine speed all the time.
The flex part is that the actual blade flattens out when the RPM's are way up there. I've towed with P/U's, Vans, cars and now my burb. All of the flex fan vehicles got the Heavy duty clutch fan put back on after instances of NOISE, decreased mileage when unloaded (.5 to 1 mpg) and some vibration in one of the trucks with a flex fan.
Before doing anything to the fan, take and tow with it first. And do the following
1.) Turn on the A/C and let it cycle for a couple dozen miles. Keep a close eye on the temp.
2.) Slow down and load it up with A/C, electrical loads, and an uphill climb. If the temp climbs past 210, turn off the A/C, Turn ON the HEATER FULL BLAST, slow to 25 in 2nd gear, roll down the windows and see how fast it recovers. If it takes about 2 minutes your fan is working fine. You'll see the gauge drop like a stone when the heater comes on.
If everything seems normal, then partially block the radiator with cardboard, and drive it around the neighborhood (to simulate summer heat in the winter) with the A/C on. If it stays below 210 you're good to go. If it goes above then remove the cardboard and time the temp drop. It should go down in less than 2 minutes.
But it's your choice. Also make sure the rest of the cooling system is up to snuff. Flush and fill, change the T-Stat, and cap. Also make sure your water pump is working good too. The Radiator may need to be rodded if you see deposits on the tubes from the upper(or right side) tank.
larry
The flex part is that the actual blade flattens out when the RPM's are way up there. I've towed with P/U's, Vans, cars and now my burb. All of the flex fan vehicles got the Heavy duty clutch fan put back on after instances of NOISE, decreased mileage when unloaded (.5 to 1 mpg) and some vibration in one of the trucks with a flex fan.
Before doing anything to the fan, take and tow with it first. And do the following
1.) Turn on the A/C and let it cycle for a couple dozen miles. Keep a close eye on the temp.
2.) Slow down and load it up with A/C, electrical loads, and an uphill climb. If the temp climbs past 210, turn off the A/C, Turn ON the HEATER FULL BLAST, slow to 25 in 2nd gear, roll down the windows and see how fast it recovers. If it takes about 2 minutes your fan is working fine. You'll see the gauge drop like a stone when the heater comes on.
If everything seems normal, then partially block the radiator with cardboard, and drive it around the neighborhood (to simulate summer heat in the winter) with the A/C on. If it stays below 210 you're good to go. If it goes above then remove the cardboard and time the temp drop. It should go down in less than 2 minutes.
But it's your choice. Also make sure the rest of the cooling system is up to snuff. Flush and fill, change the T-Stat, and cap. Also make sure your water pump is working good too. The Radiator may need to be rodded if you see deposits on the tubes from the upper(or right side) tank.
larry
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