TR2/3/3A TR3A Fan recommendations wanted

[CraigLandrum]

In the next few weeks my son and I will (hopefully) be mounting our soon-to-be refurbished radiator. In keeping with my desire to try and maintain as close to a stock look as possible under the hood combined with wanting to still be able to hand crank this puppy, he radiator has the central hole. We are are also using a stock original metal fan, stock starter, stock generator - no alternator.

The engine has been completely rebuilt (now 2100+ cc's) so we shouldn't have a scale or blockage issue inside the engine, but after all the reading I've done over the past year, I think it is a safe assumption that I can expect this close-to-stock arrangement to overheat in hot weather, long traffic light idles, or low MPH city-type driving.

As insurance against that, I'm considering mounting an electric pusher fan on the front of the radiator (but not blocking the cranking hole!), and would like some recommendations as to which ones will fit. Moss sells three different sizes (10,12,14 inches) at reasonable prices and recommends the 12 inch for TR2-TR4A. Has anyone mounted one of these in on a central-hole TR3A? Where does the temp sensor go? Any issues I should know about? What size should I get in order to keep the central hole clear?

Also FYI, we will be installing the standard radiator shroud.

Decided that it would be better to do this now before putting all the panels on the car than find out later I need it and have to tear it all down again

 

[karls59tr]

I've mounted the yellow TR6 fan(backwards) in place of the anemic stock fan and have mounted an electric fan in front of the rad that is run by a toggle switch for when I get stuck in traffic. I dont see any way you can mount an electric fan in front or behind the radiator and not block the crank hole....unless you rig up a couple of 6" fans from a newer import car...but then your really moving away from stock.

 

[Andrew Mace]

...after all the reading I've done over the past year, I think it is a safe assumption that I can expect this close-to-stock arrangement to overheat in hot weather, long traffic light idles, or low MPH city-type driving.

I'm not sure that IS a safe assumption. Many years ago, I was running a tired-but-willing, totally stock TR3A almost year-round. I do recall some very warm moments, but only in 90 degree + temperatures combined with stop-and-go city driving, and I don't recall the poor thing ever boiling over. Me? I'd give the car a chance to prove itself before spending time and money you might not need to spend!

 

[TR3driver]

I'm with Andy.

In addition, I'm starting to think that some of the original fans may have lost pitch over the years. The apparently original fan on TS13571L has appreciably more pitch than the one I recall removing from TS39781LO (tho as that was over 20 years ago, I could be mistaken).

At any rate, I'm putting TS13571L back together with the stock fan, for now. If I do eventually do the alternator & electric fan thing, it will be for increased power & fuel mileage.

 

[martx-5]

One of the guys in the local Triumph club did just what you want to do. He mounted the fan in front of the radiator in such a way that he still had access to the crank hole. Unfortunately, I don't remember what size it was.

As far as the temp sensor goes, the one I got with my fan had a probe that went into the upper radiator hose and into the radiator. They give you a tapered piece of rubber to run the capillary tube in, but it was difficult to get seated properly. They have you run tape around the whole mess, and then you push the hose on and clamp it down. I couldn't get it to stop leaking, so I pulled it out. For now I just use a switch. If I had it to do all over, I would have a pipe thread bung soldered into the top radiator tank so I could use one of those threaded capillary sensors like the temp gauge has.

 

[MGTF1250Dave]

Aloha Craig,

I think the weak link in the TR3A's stock cooling system is the propeller fan blade. The four blades do not move much air at low RPM. The fan's performance could be improved by fabricating a fan shroud (like most modern cars have) so the fan is exhausting air through the radiator. The stock setup allows the fan to paddle air around the engine compartment. An alternative is to change to a more effective fan blade. One with more blades like the optional six bladed tropical fan. I have installed a "plastic" flexi-fan blade I bought from NAPA. Although I do have an electric fan, it rarely gets used (less than once a year).

A small electric prop fan mounted on the front of the radiator can augment air flow in low rpm conditions. It would need to be small in diameter so it would not block the hand crank hole. It may be sufficent if all other parts of the cooling system are working.

The fiber board radiator shroud is helpful in directing air entering the grille through the radiator. I seem to recall that some TR3 owners in hotter climates have also added a lower shroud to direct air through the lower portion of the radiator.

In my opinion, keeping the engine block and radiator clean of sediment along with keeping the other parts of the cooling system in good working will allow your car to keep its cool.

 

[M_Pied_Lourd]

Craig,

I have a 1960 3 parts car that has a pusher fan on the rad and I believe that is mounted above the crank hole. It is out of the car and I will go out to the garage tonight and take some pics and measurements.

This fan was not thermostatically actuated as it had a small rocker switch mounted under the dash for when the additional cooling was needed.

Cheers,
M. Pied Lourd

 

[TR6BILL]

Check out www.spalusa.com for a zillion combinations of very high quality electric fans. I have one on my 6. Very well made.

 

[M_Pied_Lourd]

Craig,

Here is a pic of the fan. It is a 12 inch fan and as you can see, It just blocks the crank hole on the bottom. I think that 10 inch will be close.....but you might need to go as small as an 8. I am not sure how effective an 8 inch fan will be.....

Yes, the rad is bent!

Cheers,
M. Pied Lourd

 

[sp53]

Yes your best bet is to find the tropical fan, but I guess they are rare. I heard that the old Volvo’s used that same tropical fan, so perhaps that might broaden your search. I have one and I have seen them on ebay. I put a yellow plastic one that I painted black on my 61, but I have not driven it yet. When I put the tropical fan on my 58 years ago, I noticed a big difference in cooling. I drive all over and do not use an electric fan.

 

[Geo Hahn]

...Here is a pic of the fan. It is a 12 inch fan and as you can see, It just blocks the crank hole on the bottom...

That is the fan I use to supplement the stock fan and I can still use the crank.

I cut away a tiny bit of the plastic grille on the fan just in front of the crank hole. If a fan blade is in the way gently inserting the crank pushes it aside.

I've told the story before of passing a time-temperature display and thinking that it seemed later than a quarter past one, then the display switch to 2:30 and I realized that the 115 I saw was not the time. In otherwords, these cars can handle hot weather (though that supplemental pusher helps in slow traffic etc).

 

[PeterK]

Craig,
This is how it mounted my electric. It's a pusher on a manual switch.

I made up a couple of brackets and tack welded tham to to side of the radiator support. Then I welded two bolts that fit the fan mounting tabs to each bracket.
https://mysite.verizon.net/kentech0822/triumph/electric_fan.jpg

https://mysite.verizon.net/kentech0822/triumph/electricfanmount.jpg

I tried several fans on my 58. I wanted the TR6 fan but even when I reversed it, it interfered with the chassis support tube. But many have use the TR6 yellow fan would no problems, just NG on mine. TR4A won't fit at all because it's too big in diameter. So I found that a BMW tii fan would fit (from Mad Marx, a German road racer on BCF) and tried it. So far so good but in all honesty, the original was OK too. My radiator has a new core and no crank hole.

 

[Don Elliott]

Like Peter, I installed a 12" fan. I bought my Kenlowe fan in England and mounted it with brackets I fabricated myself because I felt that the method they sell was a bit Mickey Mouse. "Push the 4 plastic bolts provided through the fins of the radiator and mount the fan". I have a manual switch.

Here is how I did mine 18 years ago and the 12" leaves the hole for the hand crank open.

 

[prb51]

I ran the original fan on my TR3 with a pusher up front for a few years without any problem.
We have weeks of 100+ weather and the only time I used the pusher was during long stops or heavy slow traffic and it always kept the car at 185 +/- a few.
Mine did cover the crank hole and I could put it in/remove it thru the front of the small mouth. I suspect you'll have more room on a TR3a but I don't think you could fit a fan on a small mouth without covering the hole...you'd be out of the airstream.

 

[CraigLandrum]

Wow - lots of good suggestions. If I do this, I'm inclined to go with the 12 inch and cut away a portion of the protective shroud, along with a modification of the mounting system - pushing bolts through the radiator fins seems mickey mouse to me also. Will also hunt for a tropical fan or look at improving the efficiency of the stock 4 blader somehow...

A note - I live in Rappahannock County, Virginia - about an hour west of DC, located in the Blue Ridge mountains. Our county has 7,000 people and no stop lights. None of the surrounding counties is very populous, although things have been growing fast in towards DC in recent years. I would likely never drive the car into DC unless someone held a gun to my head or to attend a British Car Show, so I don't really encounter much stop and go city style driving - mainly 2 and 4 lane 45-60 Mph. Our local temps go from the teens in winter to around 100 in summer. From what some of you have said, I could *probably* get by with my stock setup in this environment. Will give it a bit more thought, but I'm likely to err on the side of caution...

The first thing I plan to do once the car is finished is take the Mrs on a spring drive along Skyline Drive through Shenandoah National Park. Speeds there are 35 mph if I recall with elevations around 2,000-3,000 feet. I can see the drive from my office window in Flint Hill.

Thanks for all the great suggestions and pictures - they really helped!

 

[DNK]

The first thing I plan to do once the car is finished is take the Mrs on a spring drive along Skyline Drive through Shenandoah National Park. Speeds there are 35 mph if I recall with elevations around 2,000-3,000 feet. I can see the drive from my office window in Flint Hill.

Thanks for all the great suggestions and pictures - they really helped!

Do me a favor- Go up to Birds Nest #4 and spit off the ledge for me and just look at the view. I'll see it through you eyes

 

[Russ Austin]

I had overheating problems for a number of years, after my engine rebuild I installed a MOSS fan. It worked for a year or so but always made a lot of noise; I bought a Kenlowe fan from MOSS UK and the temp stay at 165 to 185 all day long. Highly recommend the Kenlowe fan, it is expensive but it is the best!

 

[vivdownunder]

Hi Craig,

Chiming in a bit late here.

Our temp climbs to 106 degrees on some summer days, and I wanted to be able to go through city traffic in the 3A without any overheating.

I discarded the marginal original fan to cut noise and horsepower waste, and have a pusher electric fan the same size as Don's, but mounted a bit lower down so the crank handle hole is accessible through the blades. This is triggered by a sensor mounted in the top radiator hose, but these have to be sealed with silicone or the like, as the insert is prone to leaking. I have an over-ride switch, and separate fuse box for the electric fan. A correct skirted thermostat is important to stop coolant escaping down the bypass and missing the radiator.

This engine stays below 185 in heavy traffic on the hottest days.

Bear in mind that an electric fan can draw 10 amps, and the TR generator is only rated at about 17 amps, and that's with the engine revving, as gennies don't charge at idle. So on a hot night with the electric fan and headlights operating, most available current is taken. A big battery is worthwhile that can take occasional negative drain during extended idling, without going flat.

Regards,

Viv.

 

[PeterK]

Here's my tropical fan (for my 4A), but I'm not sure that the 3A would have the clearance to fit it.

Also, the electric 12" pusher fan (Hayden brand) on the 3A sounds like a jet turbine when I switch it on. So I only use it if I absolutely need it.

 

[PeterK]

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