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TR2/3/3A Water Pump Belt After Alternator Conversion

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M

mastaphixa

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I have purchased a Denso 12185N Alternator, had the original generator pulley modified to fit said alternator and now the original belt (from Moss) is so to short. Can someone please give me a belt pn that will get me in the ball park with this nice little 50A alternator?
Thanks,
Steve Baker
 
Not sure about belt part #'s, but you could always go to the FLAPS and see if they have or can order a belt the same width/profile in a larger diameter. Run a string around all the pulleys like a pseudo belt and measure the length of the string to get a good ballpark of the belt length you'll need.
Another option is to get a smaller pulley for the alternator. Part of the benefit of the alternator conversion is being able to run a smaller pulley because you don't have to worry about spinning the alternator faster at higher engine RPM. The reason the generator pulley diameter is so large is partly to prevent it spinning too fast. The with smaller pulley on the alternator you'll get much better charging at idle.

Robby
 
I have a list of some of the belts I tried on my TR3A with lengths. Will look for it i the morning.

I got the belt from O'Reilly.

David
 
Here's the one I use.
V3459jt.jpg

td5JLBe.jpg


Seems that Goodyear has quit making them, but you can still find close-outs on eBay at a reasonable price. RockAuto has several equivalents listed as well.

PS, here's a shot of it installed. As you can see, the adjustment comes to the middle of the range.
X4GAP8v.jpg
 
Last edited:
Steve,
I have two Tr4's both are converted to alternators. One has a regular sized pulley while the other has a slightly smaller pulley ( this allows for the alternator to start producing power at about 600 RPM). I use a NAPA 28400 belt on both of these cars.
 
Here is the belt I used.

I have an alternator with a wide pulley, a new TRF water pump pulley and the original crank shaft pulley. All 3 pulleys are very slightly different widths. It is a tight fit to get it on but everything is driving on the flanges of the pulleys.
It can be removed without taking anything else off the car.

David
Tr3A fan belt Gated TR24379.jpg
 
Thank you all for your responses.
Steve Baker
 
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