Electric Fan Installation Question

[Brosky]

I'm thinking about installing an electric fan, either in front of (push) or in back of (pull) my radiator. Any suggestions for a particular brand and the preferred installation location?

I'm favoring front and keeping the current belt driven fan in use.

Thanks,

Paul

 

[Keoke]

HI Brosky,From purely an efficiency point of view the puller Type fan installation is preferred. Which fan type to use is an individuals choice.---FWIW---Keoke

 

[trboost]

Paul,
I mounted mine in front as a pusher for simplicity's sake. There is more room & no mod's needed to the original fan required. This is used as an auxiliary fan only & is on only in traffic if needed. It brings the temps down under half in a few minutes. I made some mounting brackets & pop rivited them to the radiator frame to mount the fan more securly. I'm not comfortable with the plastic mounts that pass through the radiator core. Over time, the vibration & bouncing of the fan up & down you stand a chance of causing a leak & getting stuck. Take the time & fabricate somthing solid. Take a look at the front of your radiator, there's plenty of space to mount an aluminum strip top & bottom.

 

[Alan_Myers]

Hi,

I agree, pusher or puller is up to you. The pusher design is said to be a little less efficient, since it partially blocks air entering the rad from the front. One of the radiator manufacturers rates it as up to 20% less efficient, but sounds a little extreme to me.

Most rad manufacturers recommend a puller for maximum efficiency, but it's a more invloved project. Another reason for puller mounting is that a front/pusher mounted fan is more exposed to rain and road debris. On the other hand, the stock original fan, if left in place, will serve as a backup, if the electric pusher fan fails for any reason.

Some fans are puller only, others are pusher only. Some are reversible and can be used in either configuration.

Other considerations:

You'll probably wan to use a thermostat control for the fan. These can be non-variable type: usually come on at 185F and turn off at 170F. Or there are adjustable if you wish to play around with the temps where the fan comes on and turns off.

Some thermostats slip clamp onto the outside of a hose (not a great design), others slip inside a hose (better, but still not great). Others use a fitting that is installed in the center of a hose (still better, but adds two more possible leak points). And, others use a bung that's welded into existing steel piping (probably the best, but welding is required).

Front-mounted pusher fans are usually 10 or 12" diameter on TRs. That's enough in conjunction with the stock puller fan, and fits within the shrouding.

Rear-mounted puller fans are usually 12", but I've got 14" installed on my TR4 and have seen as large as 16". There is some overhang with 14 and 16", but they cover more of the radiator and move a lot more air. The 14" fan I've got is rated for up to a V6, 3500cc engine, about 1700 cfm if I recall correctly.

An important consideration is that any electric fan draws significant amps. Is your alternator up to it? Smaller fans draw less, larger fans draw more. Some of the larger fans draw a lot of power and will overpower most TR charging systems. Watch the amperage when shopping and keep in mind anything else on your car that draws significant power (halogen headlights, fog lights, elec. fuel pump, 1000 watt stereo, etc.).

There is not a lot of room for a fan behind the radiator, due to the crossbrace between the spring towers and the steering rack. It's possible to elongate the rad lower mounting holes and move it forward, but only a little. Measure the room available in your car and check this when shopping.

Most fans use a zip tie like arrangement that fastens the fan to the radiator. It's pretty cheesy. I agree, either rig a bracket (I did that too) or use J-bolts to hold it in place. The 14" fan mounting points were perfect for this. Don't know if that would be possible with smaller or larger fans, check mounting point measurements when shopping, if at all possible.

The big Triumph vendors charge a premium for fans, but sell ones that you pretty well can be assured will fit. However, these are off-the-shelf standard items and can be bought for a lot less at www.summitracing.com or www.jegs.com I bought mine from Summit, along with a fixed thermostat and wiring kit that included a relay and a self-resetting circuit breaker. It was Mr. Gasket brand and looks to be a good one.

If going with a puller and removing the stock fan, it's probably a good idea to leave the original fan hub in place. This is usually also a simple dampener for engine harmonic vibrations. I know this is critical on the 4-cylinder TRs, would guess it is on the 6-cylinder too.

Not applicable to your car, but on the 4-cylinder engines when a large puller fan and an alternator are being installed is an ideal time to do a so-called thin-belt conversion, including a proper harmonic dampener/pulley on the front of the crank.

Some like to add a switch for the fan in the cockpit, so it can be turned on when you wish. I didn't bother with this on my car.

Wiring the fan in, consider using a hot-all-the-time circuit. This will allow the fan to run briefly if needed, after the car is parked and turned off. Most modern cars are set up this way, so that the engine compartment can be cooled quickly.

Cheers!

Alan Myers
San Jose, Calif.
'62 TR4 CT17602L

 

[Guest]

Paul,
Why install an electric fan at all? Perhaps your overheating problem can be addressed by other means. (Assuming that you are having an overheating problem in slow traffic. If you are overheating at speed, an electric fan is strictly a bandaid for a more serious problem.) If your TR6 is basically stock, and you live in a relatively cool climate, why are you overheating at all? Have you addressed this issue and what steps can you take to resolve this problem. Basically, a stock TR6, properly setup, in reasonably good mechanical condition, shouldn't overheat to the point that an electric fan is needed at all. You might seek out help from a competant LBC mechanic to try and figure out what the problem might be. I have a fairly hot setup in my 73 TR6 and I run very cool all the time and I live in a very hot climate. This wasn't always the case. Early on I too had a cooling problem and basically totally finetuned the whole engine, covered all my bases, improved the radiator to a 4-row setup, added a shroud and oil cooler and got rid of the electric fan I had resorted to. Again, IMHO, there really should be no need for an auxilliary electric fan (unless you want to gain a few horses and get rid of the stock fan blades completely). There is no room for a large puller fan on the TR6 without discarding the stock fan (and you will have to shorten or install a custom harmonic balancer). There is no room for a large pusher fan on the TR6 and having an oil cooler. Consider your options before you go with the electric fan. You will, as stated, have to deal with the extra load on you alternator and wiring as well. The KISS rule should be observed here, again IMHO.

Bill

 

[Brosky]

A lot of very good ideas here, indeed. I am not overheating to the point of having a problem, just concerned that when it hits 3/4 in a traffic jam that I might have a problem and I'm just trying to be pro active. It had never gone beyond the 3/4 mark until the thermostat stuck yesterday and that's been replaced as of today. Under normal circumstances the car runs just fine, is tuned very well though a good friend with and inspection station emissions tester and never boils over. Since I'm planning to use the car a lot more, I just didn't want to be stuck in traffic without a little defense.

Paul

 

[71tr]

Here is a good write-up on a TR-6 electric fan conversion. I'm in the midst of a rebuild and will be dumping my old mechanical unit and going with the perma-cool setup. This thing mounts as a puller, is plenty thin and amperage draw is modest.

https://www.hottr6.com/triumph/tr6fan.html

 

[Brosky]

Now that's some serious installation. Rather than going through the crank mods, would it work as a pusher from the other side? Is there room on yhe brackets to mount it to the radiator the same way on the flip side? If so, that may be my way to go. Of course if I had the engine out like you, it would be the other route.

Paul

 

[LastDeadLast]

Brosky,

For the last six months, I have been running nearly the exact same setup as the link that 71tr gave. I have stainless headers that make the under hood temps pretty high especially in 95+ temps we get here in North Carolina. With the above mentioned fan I have had no cooling problems, but in super hot weather, I do have to run the electric fan continuously to keep vapor lock to a minimum (due to the headers). The best thing I like about the electric fan is that I don't have to hear that "jet-engine" of a OEM fan anymore; the new electric fan is nearly silent.

I did get a "fan eliminator kit" from this guy:
https://topshamautoparts.com/tr6/eliminator.htm

which is basically a nicely machined bolt and washer, but a necessity if you don't want to cut down your OEM fan extension.

For what it's worth, I've read that elimination of the fan gives you 6 horsepower, but who knows????

If you decide to do this, drop me a line, I can give you part numbers of switches and relays that I used.

 

[Alan_Myers]

[ QUOTE ]
I have stainless headers that make the under hood temps pretty high especially in 95+ temps we get here in North Carolina. With the above mentioned fan I have had no cooling problems, but in super hot weather, I do have to run the electric fan continuously to keep vapor lock to a minimum due to the headers...

[/ QUOTE ]

Headers do add to the heat levels under the hood! Have you considered wrapping them? Works well with stainless steel. (Not recommended for mild steel - have them ceramic coated instead).

Photo of wrapped TR4 headers here in the "Carbs, engine & more" photo gallery.

Also, TRs tend to trap and "dam up" warm air under the hood because there is no easy exit for it. The most likely outlet is the gearbox cover, and then the driveshaft tunnel.

I'm adding fender vents to my TR4 to give the air another exit. That project hasn't been started yet, but I plan something similar to the vents used on the 1960 TRS LeMans cars, instead of the semi-triangular Shell Rally style vents seen on works and works-replica TR4s (and some TR4A, 250 & 6s). The TRS style vents are higher and further back in the engine compartment, both of which should be beneficial, plus I just personally like the look of them better.

Alan Myers
San Jose, Calif.
'62 TR4 CT17602L

 

[LastDeadLast]

Alan,

That's some really nice pics you've got there!

I'm thinking about trying to get through to the winter then have the headers Jet-Hot coated. Although I've heard that doing that only transfers the heat to the fuel lines in the drive shaft tunnel sometimes causing the fuel contained in said lines to vapor lock as well. So fuel line insulating will probably be required (does it ever end???).

I've never thought of fender vents... I'll have to research that if I ever have the old girl painted.

 

[Geo Hahn]

Like trboost I use a pusher for auxillary for long traffic stops in hot weather. I too do not favor those plastic mounts that punch thru the rad, I used 4 brackets fashioned from beheaded carriage bolts bent into and ell and run thru the mounting ears on the fan:

Mine was just the basic auto parts store fan... brand 'Imperial' I think. Simple install and effective for what I had in mind.

 

[Brosky]

Looks much better than the plastics straps. Do you have this on a sensor and relay or just a direct switch in case it's needed?

Paul

 

[Simon TR4a]

I too have a pusher fan installation,a 12 inch Hayden, activated manually by a switch under the dash on the passenger side.
Together with a radiator recored with fine pitch fins and an extra row of coolant tubes I have no problems holding temperatures down.
My only problem with the pusher setup has been finding a good location for the oil cooler.
Running the fan with the engine off is of limited value since the water pump is not circulating the coolant, so you are cooling the radiator, not getting heat away from the head, and especially exhaust valves, which is the hottest part of the engine; I suppose an electric water pump would good but I doubt this is a problem for most of us.
Simon.

 

[Alan_Myers]

[ QUOTE ]
Running the fan with the engine off is of limited value since the water pump is not circulating the coolant, so you are cooling the radiator, not getting heat away from the head, and especially exhaust valves, which is the hottest part of the engine; I suppose an electric water pump would good but I doubt this is a problem for most of us.
Simon.

[/ QUOTE ]

That's true, Simon. Running the fan after the engine is shut off will mostly cool off the radiator (unless there is some coolant still moving due to convection... doubtful).

It will move the air under the hood to dissipate radiant heat more quickly. A possible side-benefit is reducing the chance of vapor lock in the fuel lines and/or carbs.

Cheers!

Alan Myers
San Jose, Calif.
'62 TR4 CT17602L

 

[Alan_Myers]

[ QUOTE ]
does it ever end???

[/ QUOTE ]

No, it doesn't! /ubbthreads/images/graemlins/wink.gif

Cheers!

Alan Myers
San Jose, Calif.
'62 TR4 CT17602L

 

[Geo Hahn]

[ QUOTE ]
Do you have this on a sensor and relay or just a direct switch in case it's needed?

[/ QUOTE ]

Because I did not really have an overheating problem I used a manual switch. Really only need it when traffic gets slow on very hot days.

I switched it on the ground side of the fan to simplify the wiring and make it easier to conceal (just one black wire run thru the engine comaprtment).

 

[Brosky]

Thanks. That's really what I was looking for in the event that I move forward. I have a lot of parts to be installed and it's time to cool it on the spending for a while. At least as the weather gets colder and the fact that I never drive it the snow, the cooling fan will move into next springs to-do list.

Paul

 

[skikir]

I put in a Hayden fan from GI Joes with an adjustable thermostat. Mounting is cheesy but it works. Mounted it as a pusher to get it out of the engine bay. It's been in the high 90s here and have not had a problem. Temp gauge does not move. It comes on a lot in town as indicated by the amp meter and have never seen it come on on the highway. I can problably adjust cut in higer. I feel more power and get consistantly over 25mpg. The only other mods are electronic ignition and K&N air filters.

 

[Brosky]

That's pretty much my set-up. K&N's, Petronix going in this weekend. This car sat in our garage for 18 years and I did nothing but start it occasionally and take it for a three mile ride once or twice a month (but never in winter) to blow out the carbon. After having the carbs rebuilt by TRF two years ago I started to get interested again and it's getting constant attention now.

Paul