Testing viscous fan

[john.thompson068]

It appears there might be two things I see but might just be optical.
Where is the fan sitting in relation to the shroud opening. Looks like the blades are really tucked in there. They should be in the circle as to not allow air to circle behind them. Remember path of least resistance. IF air can just circle around from behind to the front instead of through the rad it will.

As for thermostat. Goal is to act like a switch one and off to allow coolant to cool sufficient in the radiator. 160 is great if you got a monster cooling system or trying to squeeze some HP out of a FI motor. Once temp reaches 160 it just stays open and fluid can not cool fast enough at idle or low rpms when airflow is less. IF it was the 180 or factory temp it would open and once liquid cools below it will open again and start cycle again.

And how is timing. IF it retarded just a bit that can make it run hotter as well. 10 degrees is a big difference in your upper end.

just my two cents

I can't alter where the fan is sitting. It should be okay since it is using a regular size radiator, regular water pump, and a MP fan. Maybe the box on the shroud is not the best design, but I cannot change that. Timing is set at about 14*. Are you sure about the thermostat? A 180* thermostat does not open when the motor reaches 185* and then stay open until the motor cools to like 175*? Then closes until the engine temperature goes back to like 185*? Am I thinking backward?

 

[Sweet5ltr]

I can't alter where the fan is sitting. It should be okay since it is using a regular size radiator, regular water pump, and a MP fan. Maybe the box on the shroud is not the best design, but I cannot change that. Timing is set at about 14*. Are you sure about the thermostat? A 180* thermostat does not open when the motor reaches 185* and then stay open until the motor cools to like 175*? Then closes until the engine temperature goes back to like 185*? Am I thinking backward?

180* thermostat opens around 185-190* (only takes a few seconds to increase ten degrees) and cools the coolant below 180* before closing. It's all thermal and mechanical, it opens around 180* and cools below this temperature before closing. If their isn't enough air moving through the radiator core to cool the flowing water, then obviously it will never close and will continually increase temperature before overheating. That is why you will not overheat while driving with a air-flow deficiency, but cannot keep cool during idling and slow traffic.

14* initial timing sounds fine.

 

[Sweet5ltr]

I either bought the 50A or the 60A cause that is what the parts store just told me they had available for my car. There is no way for me tell which one I have unless there is a special test I can do with a voltmeter. What is up with that 11.75" 2210cfm fan drawing 23.4 amps? I am comparing it to a 16" 3300 cfm fan that draws only 18 amps. That 23.4 amp fan must need all that power to push that much cfm with such a small fan blade right? I don't know if I would bother with that 23.4 amp fan even with a 90 amp alternator. I am beginning to doubt that its benefits are worth the amount of power it takes. Especially if you have another fan acting as a puller fan. I am seriously considering that fan you recommended, but I am also seriously considering just doing an alternator upgrade too. I have concluded my research on alternator upgrades and am making another thread over in the electrical section. Please take a look at that you guys. If I had a 3300 cfm fan with 18 amp draw, and a 1500 cfm fan with a 10 amp draw, that would be almost 5000 cfm of air flow. That would have to be enough to cool any motor, and only drawing a total of 28 amps, which is barely more than that single fan alone. That 23.4 amp fan is crazy.

anything larger than a factory alternator is going to require wiring upgrades. I moved up to a 65AMP alternator, which I believe is the largest installed during those years. You are exactly right. 12" fan pushing similar air flow as a much larger fan, is going to require much more AMP draw. An alternator upgrade isn't necessary, if you plan on sticking with a lower amp fan.

 

[john.thompson068]

180* thermostat opens around 185-190* (only takes a few seconds to increase ten degrees) and cools the coolant below 180* before closing. It's all thermal and mechanical, it opens around 180* and cools below this temperature before closing. If their isn't enough air moving through the radiator core to cool the flowing water, then obviously it will never close and will continually increase temperature before overheating. That is why you will not overheat while driving with a air-flow deficiency, but cannot keep cool during idling and slow traffic.

14* initial timing sounds fine.

That is exactly what I thought. So first I need to increase my cooling capacity before the 160 thermostat, or even the 180 degree thermostat will have any positive impacts on my cooling system. In fact, depending on the efficiency of my upgrades, I may be better off with the 180 thermostat which will allow the coolant more time to cool off in the radiator. I am upgrading my system until I can run a 160 thermostat and run cool. Check out my alternator post you guys over in the electrical and ignition forum.

 

[john.thompson068]

Oh wow. The condenser for air conditioning will cover the entire front of the radiator. Take a look at it at this link: http://www.classicautoair.com/manuals/1-1065Manual.pdf

Also, I just stuck a tape measure on my radiator and it measure 25.25. So it is probably a 25x19.


Well here is the plan. I can order a Tuff Stuff 100A alternator which will bolt into the factory brackets. Then I will order one 10" electric fan. Later before I install air conditioning, I will move my trans cooler. I will get the long skinny type cooler and put it down behind the front bumper with a fan on it (I run a tight PTC 4000 stall converter). Then I will install the condenser. I will then order another one of the 10" fans and mount both fans to the condenser. There is adequate clearance to mount fans on top of the condenser especially if I mount them at the bottom of the condenser. As you can see the condenser only sticks out from the radiator by about an inch. I will retain the original factory fan and my cool looking shroud as of this time.

 

[john.thompson068]

Actually, I will order 10" fans and hook them up this weekend. The other one can blow through my trans cooler in the meantime.

 

[mopar350]

I see you have gone with elec. fans. good idea but for future referance. the fan blade should only be half way into fan shroud never ever all the way in or all the way out. i got a 1967 383 for this very reason the person just insisted the block was cracked.

also to test a clutch type fan allways do this when the engine is cold. if the fan makes 2 full turns it is junk. make sure there is no oil running out of clutch area also. if there is toss it and get a new one. as you can see i now have that very same 1967 383 in my 87 work truck with no over heating problems even when i have it loaded with 1500-1800lbs in the sc heat.

 

[john.thompson068]

Thanks. I have a Flex fan that sits in their correctly now.

 

[Sixer]

It appears there might be two things I see but might just be optical.
Where is the fan sitting in relation to the shroud opening. Looks like the blades are really tucked in there. They should be in the circle as to not allow air to circle behind them. Remember path of least resistance. IF air can just circle around from behind to the front instead of through the rad it will.

As for thermostat. Goal is to act like a switch one and off to allow coolant to cool sufficient in the radiator. 160 is great if you got a monster cooling system or trying to squeeze some HP out of a FI motor. Once temp reaches 160 it just stays open and fluid can not cool fast enough at idle or low rpms when airflow is less. IF it was the 180 or factory temp it would open and once liquid cools below it will open again and start cycle again.

And how is timing. IF it retarded just a bit that can make it run hotter as well. 10 degrees is a big difference in your upper end.

just my two cents

Agree concerning the fan placement in the shroud especially-should sit just inside the opening.