Topic: Electric fan installation

[trbleman]

I have a newly rebuilt 289. The cylinders were bored 60 over and new flat top pistons installed. The motor runs a little hot so I took out the old fan and put in a 14" electric fan. Where would be the best place to connect the wires so that it does not rob electricity from spark. Thanks for the help.

[Jeff73Mach1]

.060 overbore on a smallblock ford will usually lead to overheating problems.  Electric fans tend to move LESS air than mechanical fans.  Often a missing fan shroud will cause overheating problems.

If you are 100% dead set on using an electric fan, you will want a controller, wired to the battery positive side with a "Trigger wire" tied to the ignition circuit which only activates a relay and allows the draw to come from the battery.  Google search and you will find lots of diagrams, but without knowing what controller you are using, telling you how to wire it is difficult.  Do not use the coil or starter solenoid as your power sources.  I took a meter and back probed the voltage regulator to find an acceptable choice and it has worked fine for me.

Some people want electric fans wired to run even after the car is turned off.  It is possible to do this without wiring  a relay or trigger wire, but a malfunction will lead to a dead battery.  There are timers out there, but wiring them again is specific to the unit you choose to use.

[trbleman]

The car came with a four blade fan and shroud. Would using a five blade fan and shroud solve the over heating in city driving? I also did not mention that the car came with an auxillery transmission cooler on the radietor. Would that interfere with air circulation? Also, I am currently using the stock manifolds with a dual exhaust. Would headers help cool the engine or add more heat?
Thanks so much for your help.

[Jeff73Mach1]

First make sure you run a 50/50 mix of anti freeze and water as pure antifreeze does not cool as well as the mix.  There are various water wetters available from places like red line and Be cool that can lower temps a few degrees when used with your coolant mix.

A five blade fan and shroud might make a difference, but do you have a clutch driven fan or a solid driven fan?  If it is clutch driven is it  in good shape?  Was the water pump replaced and what thermostat is in the car?  You can get a high flow water pump which can help, or a larger radiator but both are more expensive and often not necessary.

Overheating means different things to different people.  Ford gauges are notoriously inaccurate, consider using a infrared thermometer to check the engine for signs of true overheating.  To me an overheating engine is one that is puking coolant, not one that the gauge reads high.

Headers will typically increase under hood heat as they are much thinner metal, but I don't think they will make any significant difference in engine temp.

As to the transmission cooler-it probably isn't much of a problem, make sure it is mounted with some space between it and the radiator.

What is the condition of your radiator? 

[trbleman]

Thanks for the responce. This coming Saturday, I will spend the day removing the electric fan and reinstalling the original four blade fan (not a clutch fan) and shroud. I am also going to drain radiator and make sure it has a 50/50 mixture.
It does have a new stock water pump with a 180 thermostat.
I will also buy an infrared thermometer to get an accurate temp reading.
The transmission cooler does not have a space between it and the radiator. I will fix that issue as well.
I have not had the radiator checked, but the last time it was drained, (6 months ago) the fluid was relatively clean.

[Jeff73Mach1]

If that doesn't do the trick and you want to try a five blade fan, I have one in my basement.

A couple of other thoughts, if you are running ported vacuum to the Vacuum advance, then your car does not get the advance at idle that manifold vacuum provides.  Advanced timing at idle allows more of the heat in the combustion process to go out through the exhaust instead of being absorbed by the block.  This would be one of the 1st things I would check.  If you change it from ported to manifold vacuum you will need to readjust your idle mixture screws on the carb.

Also I would read the plugs.  They should be brown, rather than white or black.  If they are very light in color, it both confirms heat and suggests that your air fuel mixture is lean.  A richer mixture is easier on the engine and has a slight cooling effect.  Idle mixture adjustments will do nothing about this.  If you need to richen up the mixture, you will need to rejet the carb.

[trbleman]

Thanks, I will look at those options before tackling the others.

[trbleman]

Yesterday I removed the electric fan and put the 4 blade fan anf shroud back on. I also checked and the vacuum advance and it is hooked to the base of the carb. The plugs are fairly new so not able to read color changes. Several months ago I bought a 600 holley 0-1850-s but it ran too rich. The spark plugs were always wet. I contacted Holley and they suggested I jet it down. I jet it down to .22. It was at .26. I drove the car yesterday and noticed a slight hesitation just before a load was applied. Isn't that an indication of it running too lean? The car was still running a little warmer than usual at a stop light, but it did not over heat. When I shut the engine off there was some over flow fron the over flow tube. I guess about a quart or so. 

[Jeff73Mach1]

My inclination would be to jet it up 2 sizes.  I'd rather run just a bit rich than lean.  As I said initially, a .060 overbore is more than most people consider acceptable for a thin wall casting windsor block.  Water wetter, a bigger radiator and a high flow water pump is probably in your future.

[jethat]

Many early Mustangs came with small 2 row radiators. My mach I had one when I got it. (probably wasnt the original) I put a 4 row radiaator and a 7 blade flex fan and the car never gets hotter then operating low temp on the old gauge.. Flex fans I've been told have a tendency to come apart so theres that to factor in.. I would look at the radiator at any rate and see if there is a larger one avalible.