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TR6 TR6 fan on TR3A

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TuffTR250

Jedi Warrior
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Will the red 13 blade TR6 fan and hub fit on a TR3A? Also will the 13 blade fan help with the cooling while waiting on a stop light in hot weather?
Regards,
Bob
 
Moss has a fan adapter kit for the TR3 that allows you to use a TR6 fan. I had this installed on my TR3 5 years ago when I had my engine rebuilt. Since then I've never had any over heating problems. My temp gauge shows about 88celcius after the engine warms up and doesn't budge even on the hottest days. https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=66775
 
I have a yellow TR250 fan turned backward on my TR3 but it doesn't seem to move much air. I think by putting it backwards a lot of air movement is lost. I don't have any problem even on 90 degrees days except when setting idling at a long stop light. It doesn't boil over but gets hotter than I'd like. What would keep the TR6 fan from working on a TR3, is the hub too thick and thus moves the fan too close to the radiator?
Regards,
Bob
 
Bob-

i haven't done this so I'm just guessing - but I don't think the red fan will gain much in distance because you have to use that extra adapter piece that bolts between the fan and the hub itself. I doubt it will make it as thin as running a yellow fan when its installed backwards.

Randy
 
We had this discussion some time back about whether theblades actually change when the fan is put on backwards. If I remember correct,it did not matter. Anyways, I put a yellow fan on my TR3 and it helped significantly.If there is an adapter made for that it would make things easier because I hadto make some spacers and hold them in place with tape and deal with getting thewhole deal on there functional. The stockfan just does not work very well, so come up with something. The best bet is tofind an old original equipment tropical fan.

 
bmwfan_front.jpgThis is what I have on my 58. It's a BMW 2002 tii fan recommended by Christian Marx who raced with one at the time. I had to bore out something but was easy to do since it's plastic. Works well, fit perfectly, and yes it IS balanced despite the awkward looking blades.
 
I have used a TR6 fan (backwards) and needed a spacer to get it far enough forward. Made from a piece of cutting board, looked like this (fan painted black for stealth):

TR6FanSpacer_zps9baddce5.jpg


Reversing the fan does still blow the air the same way (just as a nut will screw on no matter which way 'round you use it) but those blades seem to have a slight airfoil that I suppose makes them somewhat less efficient operating in the opposite orientation.

Later went with a Tropical which works well and looks 'more correcter':

Tropical_zps3dccced8.jpg


That BMW fan is just plain strange.
 
sp53 said:
We had this discussion some time back about whether theblades actually change when the fan is put on backwards. If I remember correct,it did not matter. [snip]
Click to expand...

If the fan blades were flat, this would be true. But the yellow TR6 fans are curved, and optimized to spin in one direction. When installed backwards, the air does still move in the correct direction, but the air flow is reduced. Kinda like scooping ice cream with the spoon upside down. :smile:
 
Geo Hahn said:
Reversing the fan does still blow the air the same way (just as a nut will screw on no matter which way 'round you use it) but those blades seem to have a slight airfoil that I suppose makes them somewhat less efficient operating in the opposite orientation.
Click to expand...

Guess I took to long to submit my post. So, yeah, what he said ^^^ :D
 
Well...that one is even cheaper.
That NEVER happens
 
Peterk, does the 360mm BMW fan move as much or more air than the 6 bladed TR3 metal Tropical fan? I suspect the BMW fan is much lighter weight. I'm not adverse to the BMW fan if it works.

Peterk, also in your trials of all the different fans, did you try the 13 blade red TR6 fan on your TR3. What were the results?
Regards,
Bob
 
Never tried the 13 blade fan. The BMW is very light compared to the tropical fan. It is quiet and keeps my gauge steady. And available compared to the tropical fan scarcity. I do have a tropical but reserved for my 4A. I really haven't swapped since installing the BMW fan when I had the apron off.
 
I have been running at TR6 fan on my TR4A for a long, long time. I have a yellow one on there. I had a white one before and broke a blade off trying to turn the engine with it, but they work fine on a TR4A. Is that piece on the front of the pulley different on a TR3? I guess it would be to fit a crank....
 
Moss wants $139 for their extension.It occurs to me that the stock fan extension could be shortened by cutting and rewelding. Wonder if this is practical to save a few bucks?
 
DanB, the yellow TR250/TR6 fan fits directly on the TR3 extension, but the extension is too long so the fan has to be turned backward. Which I believe impacts it's performance.

karis59tr, I suspect the TR3 fan extension could be cut down and rewelded, but you'd have to be VERY careful to get it perfectly straight or you'd introduce wobble on you crankshaft which you would not want. I personally don't think it is worth it to try to cut it down. Might be better to call some of the used parts places to see if they have a shorter extension that would fit the TR3.
Regards,
Bob
 
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