How do you best mount a radiator fan?

[JohnK]

I got a generic hot-rod electric radiator fan with my kit that mounts on the surface of the radiator with plastic assemblies. These assemblies consist of round plastic strips a couple of mms in diameter, directional barbs run along their length and there is a foot at one end. Thread a strip through the radiator fins and through a hole on a fan bracket. Secure the fan with a plastic washer threaded onto the strip, the barbs preventing it from pulling out.

 

This is simple and cheap. The fan isn't heavy and the plastic seems reasonably stout. So it seems OK.

 

Downsides: Once it's put in place, if you want to change anything you destroy the mounts. Plastic stretches so the fan's gonna move around some, which is less than desirable as things wear and get looser and looser.

 

Anyone know of alternatives to this approach that would make you feel more comfortable if you were in a say a 24-hour road race, or maybe about to start the One Lap of America?

 

 

http://www.usa7s.org/aspnetforum/upload/1547641996_Radiator.jpg

[RDROCKT]

Hi John,

As you may surmise, I have the same fan and mounting arrangements. I have not encountered any stretching of the mounts in nearly six years of racing and touring in my Ultralite S2K

If you want to try it, I might suggest leaving the strap a bit long when trimming it and occasionally giving the tail a bit of a tug to make sure it is snug.

 

In the event that you want to replace the straps altogether, Autozone and most auto parts stores have them in stock.

 

 

 

[scannon]

Hi John,

 

That looks like a Spal fan and plastic finger mount. I have a similar setup on my Caterham radiator. I made four small brackets out of 1/2" angle aluminum that run from the end of the plastic finger to the mounts on the radiator. The fan is mounted very solid to the radiator.

 

Spal has a selection of those plastic fingers, you may be able to get longer ones that will reach past the end of the core or to that radiator mounting bolt shown on the side of the picture. The slots on the fan end of the fingers allow for fore and aft movement to bring the fan up close to the core.

 

Skip

[powderbrake]

I ditto redrockt's reply.

Have had no problems on my Ultralite's fan mounting.

 

That white thing in the upper right isn't the inlet is it? It appears to be on the wrong side of the car.

[WestTexasS2K]

Been using the same setup with no problems for thousands of miles. I do mount a little rubber washer between the fan and radiator to help keep chaffing down. Those little placstic strips seem to hold pretty well.

[slngsht]

My 30 year old Rotus had the same fan when I bought it 4 years ago, and I just finally pried it off this year because the radiator had developed a leak. So seems like they work just fine.

[JohnK]

Thanks to all.

Hard to beat Chuck's experience along with Jerry's; longevity under lots of use is proof enough of the mounts' being robust. If I get energetic, I may buy myself an extra measure of maintainability by adding aluminum brackets to the ends of the existing brackets, as per scannon's solution.

 

The white thing upper right on the radiator is a paper towel protecting the (disconnected) top radiator bleed. Why my radiator has one of those requires an explanation of interest to those wanting to learn more about cooling systems and why you should feel OK buying Griffin radiators. I fabricated my cooling system according to the schematic in Carroll Smith's "Prepare to Win", page 123. When I first tested the system, the right side of the radiator wasn't getting hot. I thought about this for a while and then called Griffin. They made me jump through all sorts of hoops before finally saying "OK already! Send us the radiator and we'll have a look at it". As I suspected, there was something very wrong with the radiator and they called me back, mumbled something about the baffles that separate the upper and lower portions of the tank(s) and said they were building me a brand new radiator. They were embarrassed. In the course of the discussions I had with Griffin, it was said that all the systems they'd worked with in race cars had top radiator bleeds, and they added one gratis to the new unit they were building for me. Insurance against air pockets, supported by lots of experience. They also re-installed a bung for the Honda radiator fan switch that I had welded into the original radiator. My install of this bung was sound and solid. Their install was sound and solid and beautiful (welder's envy).

Anyway, the top radiator bleed connects to the surge tank and along the way that line tees to a fitting that connects to the top engine bleed. I learned about venting and pressurized radiator caps too: the former go on radiators, the latter on surge tanks. Stant technical help gave a very clear explanation.

 

Also, the (Sirrocco drag race model) radiator that comes with the kit had it's hefty mounts sawed off, and the fittings used to mount the radiator to the frame were designed by Griffin to mount a fan shroud. I found Reid Supply carries rubber mounts that, unlike the supplied bonded rubber mounts, were strong in shear and made some brackets to implement these. Each is good for 75 lbs in all directions, the supplied mounts are good for 5 lbs of shear and basically designed to work just in compression.

 

So if I hadn't gotten a bad radiator, I wouldn't have learned all this usefull stuff!

[lowflyer]

The plastic ties will probably outlast the car, but here's a tip for you.

 

Go out and buy a spare set now. The reason is pretty simple, at some point you will need to do something to the car that will require the removal of the fan, whether it be a rad repair or such.

 

Having a set of the ties "in stock" will save that (almost always) last minute trip to the auto parts store before an important trip.

 

Don't ask me how I know this!!!!!