Timer for pusher fan

[Michael Oritt]

As with many other things Healey, personal experience with auxiliary fans--pusher or puller--seems to vary from car to car. I have had a pusher attached to the cross brace on my car for years and it serves well. I have it wired directly to a dash switch--no timer, no thermostatic switch--and if I know I am approaching a challenging situation such as traffic, etc I turn on the fan in advance of the event. My car normally operates at 180 degrees and while running the fan will not prevent the engine temp from ultimately going up it does slow down the rate of rise considerably.

One of the criticisms of the pusher setup is that the fan blocks more air flow than it produces. I don't believe that anyone has conducted real tests and this conclusion is probably based upon empiric observations. I have noticed that if I increase my highway speed from 65 to 75 on a warm day unless I turn the fan on the temp gauge will climb to 190 whereas running the fan keeps it at 180. This may reinforce the conclusion that the fan does block air flow, at least at high speed, but IMO its utility at lower speeds, and especially in stop-and-go traffic, more than offsets this effect.

 

[warwick-steve]

Hi I can imagine that the thermostatically controlled switch is the better option however I decided that a manually operated switch would suit what I wanted. I fitted a new uprated radiator and a pusher fan a year ago and all has been OK. The manually operated switch just allows me to turn the fan on if the temperature creeps up if I am stuck in traffic on a really hot UK summer day ( it can happen!). The relatively cheap option of a timer (yet to be fitted) just gives me the assurance that it will time out if I forget to switch off.
The pusher fan has caused no problems due to its position. Normal running temperatures are fine.

Before fitting the fan I experimented with fitting baffles at the front sides and at the top front of the radiator. The side baffles remain ( clip on rubber profile) but the top baffle plate was removed as far from helping it increased under bonnet temperature and I concluded that this option would only be advisable when wing/fender vents are used.
Steve

 

[Deleted member 21878]

i am getting my pusher fan today and hope to mount next week. i am curious if it is better mounted, to the radiator or to the cross brace? do you get a bounce effect off the radiator when set to the cross brace? i seem to remember reading that some test by a Tiger's club found the fan mounted an inch from the radiator worked best.

i plan to start out just connecting it to my driving light circuit to see how the fan does at cooling. hoping it will help me decide where to set the cut-in or more likely the cut-out temp. i bought the relay/timer and i have a thermostat. So thinking some tests should help me decide which way to go.

i also tried 2- 6" fans angled up at the radiator a while back. i found they had no effect. these fans did not move enough air. To make it work with any fans, i think that i would need some better duct work directly to the radiator as the air pushed out went everywhere.

 

[GregW]

Someone should try installing a Dyson fan.

 

[Michael Oritt]

Greg--

Interesting idea! The Dyson 06 10" round fan runs on 110VAC and reportedly draws 26 watts, so a small inverter/power supply should work.

I think you should be that "someone" so please let us know how it works....

 

[warwick-steve]

I installed my pusher fan on brackets fixed to the upper and lower rad side mounts. The fan sits about 1/4 inch from the front surface of the rad core. This hasn't been any problem.
Steve

 

[John Turney]

I didn't need a pusher fan until I installed AC. Now it has a pressure switch from the AC, a thermostatic switch for coolant temperature, and a hand-off-auto switch on the dash.

 

[Patrick67BJ8]

I didn't need a pusher fan until I installed AC. Now it has a pressure switch from the AC, a thermostatic switch for coolant temperature, and a hand-off-auto switch on the dash.

Same here, I was okay until I installed AC system. Larger radiator core, Trinary Switch for compressor, engine coolant system and a manual override switch, Fast idle system(just installed), for when AC is on and idling. Also increased electrical, Alternator, negative ground.

 

[JoeCA]

For my pusher fan install, the radiator repair guy I use soldered 4 studs to the radiator frame. I used SPAL fan mounting brackets (cut shorter and bent). The fan is ~ 1/4" off the radiator core and just fits in front of the X brace. The fan is controlled by a Derale fan controller which allows the fan to be off (controller disabled), on/off determined by radiator core temperature sensor or manually controlled on/off (controller enabled). I have a LED light located by my toggle switches which lights whenever the fan is on. That way I know if it is on when driving at speed. I located the fan controller high on the passenger side inner fender. SPAL also sells a wire connector pig tail which didn't come with my fan which simplified the wiring.

I kept my original 4 blade fan. For a low tech air flow test, with the hood down, engine idling and fan off, I placed a shop towel on the grill....it just falls to the floor. With the fan on, the towel was held firmly to the grill.

I am pretty happy with this solution. It doesn't seem to impact the operating temperature much (if at all) when the car is moving. It definitely helps when stuck in traffic and when I back the Healey down the long driveway to my shop.

Here's a couple of photos of the install.

I have also fabricated a "bottom" to the radiator air deflectors just to see if it will help with directing air flow to the radiator, but I have not installed it yet.

Joe