Topic: Fan on backwards?

[Chris]

My radiator is overflowing coolant. The engine is a 260 V8 with AC; I'm not running the AC and it's still going about 3/4 across the engine temp scale. I have the 195-degree thermostat installed. I have it filled when cool about 1-inch from the rim of the radiator cap. When the car gets hot, coolant leaks out the overflow tube (about a quarter of a container of 50/50).

I was just wondering if I had the fan in correctly, seems to me I can feel more air going back towards the engine than through the radiator. I did not want to install an overflow tank as it's not original, so I'm trying to find a way to keep the engine cooler. Since the engine rebuild was not long ago, I'm ruling out the water pump and radiator as possible factors (stock radiator with NOS recore). Pictures of the fan installed are below.

[CharlesTurner]

You have it on the right way.

Is this a newly rebuilt engine?

[NEFaurora]

I just went and looked at quite a few pics of a original 260cid motors that have been unmolested.  Two big things stand out.  #1, Your fan is slammed right up against the radiator.  It should not be.  There should be at least a 1" to 1 1/4" gap between the Fan and the radiator,  Your fan and spacer looks to be correct. #2, Your main fan pulley looks very strange and unusual and not like a normal 260/289 fan pulley.   Can you take some pics of the main fan pulley from the front (where the belt is) so we can see it better and see what's there and what's going on.  It will help diagnose the problem.  I am thinking that your main fan pulley bell may be from a Ford truck of the same period or something.  We won't know until we see some better pics from you of the front part of the engine.

PS: I'd swap out that 195 Degree Thermostat for a 180 Degree Hi-Flow thermostat immediately also.  Make sure it is a Robertshaw or Mr. Gasket Three Prong front Hi-Flow thermostat.  They are the best. You'd be surprised how 15 degrees can make a world of difference.  Also, You may have a combination problem, Not just one little thing, but a bunch of little things.

Thanks,

Tony K.

[Chris]

Charles,

It is a newly rebuilt engine. I'm running the break-in oil still.

I can take some pictures of the fan pulley, but it's the early style cast iron pulley for 64 1/2. I have pics of it with the casting numbers that I'll also post. The fan is not all the way inside the shroud. I can measure the distance away from the radiator, but I'm guessing it's at least an inch away.

I'll post the pictures and measurements tomorrow afternoon. 

[NEFaurora]

You may want to ditch that Cast iron pulley. I'm not sure that it was available with the Mustang when new.  It may be a big cause of your problem.  Even Mustang #1 Vin#5F08F100001 had a standard steel main fan pulley that is seen on later 289's and that car also has power steering.  It has the 260cid V8.

Tony K.

[suskeenwiske]

> I agree with the 180 degree High Flow Thermostat. It's possible that your old Thermostat was sticking open and replacing it may just fix the problem.
> And it sure does look like the leading edge of the Fan Blades are very close to the Core.
> Does the overheating occur on the highway or just city driving?
> Check that there is nothing preventing free flow through the A/C Condenser and Radiator; leaves, bugs, dust/sand, overly thick paint, bent
    cooling fins, etc. The Radiator has to be able to cool the water sufficiently before returning to the Engine. Great Air Flow is all important!
> You may also want to consider having the radiator shop do a flow check on your Radiator and make sure that the Radiator has the correct number of
    rows. Too few rows will return overly hot water to the Engine.
> A bad Radiator Cap is a possibility. If it opens too soon, the closed Water Circulation System opens to atmosphere and will allow the Water to boil
    more easily.
> Is there enough Antifreeze mixed with the water. Too little will cause the water to boil at a lower temperature.
> Engine Timing, particularly 'Retarded Timing', will cause extra Engine Heat.
> The Water Pump could be at fault if for some reason the impeller is loose and is free spinning, causing poor circulation. It may be an incorrect Water
    Pump.
> Have the Engines Cylinders been bored out to the limit? That can also cause overheating requiring additional measures to keep things cooler.
> Poor circulation through the Engine Block, incorrect Head Gaskets, blocked Water Jackets. May need to do an Engine Flow Test.

It usually turns out to be a simple problem, don't let the Engine possibilities worry you, but I thought I'd mention them just in case.

Also, I'm no fan of Water and Antifreeze. After the problem is fixed you may want to consider using Waterless Coolant. It's more expensive up front but does not break down and never boils as it contains no water for air to boil out of. You can actually take the Radiator Cap off at full temperature; there's no pressure. You do have to go through a Flushing Step to rid the system of all water first but once done, that's it and the Waterless Coolant will not need to be changed for some time if ever.

Good luck, I hope it turns out to be a simple problem. let us know what you find.

Ray

[GT500KR]

I'm pretty sure that the cast iron pulley is correct on a/c equipped early cars.

[Chris]

I measured the distance the leading edge of the fan is from the radiator and it's about an inch away. The pulley is the correct cast iron version, described in Mannel's book, casting numbers match up. I'm also using the correct thin-base fan spacer specific for AC applications on 64 1/2s.

I think the problem may be the 195 degree thermostat. I just put this in when I fixed a small leak coming from the thermostat housing. I had 160 degree thermostat in there and it was running about half way across the Temp scale. Is there any impact on the amount of heat put out by the heater if a lower thermostat is used? If not, I may go back to the 160 vice the 180 degree thermostat.

The engine was rebuilt, balanced and blueprinted. The standard bore for the 260 is .38, but my engine had been rebuilt once before by a previous owner and my ending rebore I believe is .42. I think the max allowable rebore for the 260 is .46. I know anything over standard bore runs the risk of increased heating. I'll provide an update after I swap out thermostats. I attached pictures of the pulley and fan spacer for reference.

[Chris]

I swapped out the 195-degree thermostat for a 180-degree high flow thermostat from Mr. Gasket. The engine temp is not quite at halfway now, so that seemed to fix it.