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Subject: Correct 8N Fan Belt?

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Jim Lovejoy    Posted 07-18-2020 at 10:01:39 [URL] [DELETE]        [Reply] [Email]  
  • Correct 8N Fan Belt?
  • Recently (June 27), I had questions regarding the connection point for the generator belt adjusting arm (8N-10145). With that favorably remedied, a new question arose regarding the correct fan belt. I ordered one from a well known & highly recommended Source which verbally assured me that the belt was 46-1/8 long and was the correct belt for the 1949 8N (Ser 8N-214385 with front mount distributor). The belt received is an "Agribelt" labeled as S.18834, Fan Belt-B43/B1090 manufactured by Sparex. The belt was not notched as advertised by the Source! With some trouble, I installed it with the result that the air space between the generator and manifold is so small that I can barely slide a piece of paper between these components. (Yes, I have the 1/2" deflection.)

    I'd like to think that Ford would not have had the generator and manifold so close. Am also thinking that a belt with a smaller cross-dimension would fit deeper inside the three pulley grooves with the result that the generator and manifold would ultimately have more distance between them. Opinions please!

    Lastly, can you read the belt size information from one of your known good belts? Is it notched?

    Thanks,
    Jim L.

    Tim Daley(MI)    Posted 07-18-2020 at 16:41:37 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Correct 8N Fan Belt?
  • The front mount belt on the 8N is p/n 9N-8620-B -should be what part you ordered. Any other numbers are just manufacturers part and model numbers so verify them for reference against the Ford p/n. Seems length is correct -46-1/8" or so but don't hold me to that; check the archives. If you order an 8N-8620 belt you will get the 41" belt (don't hold me to that), the one used after s/n 8N-263844 when they moved the generator to the LH side of engine and released the side mount distributor on the RH side. Notched or flat -doesn't matter. Plain flat was all that was around back then, only newer styles are notched. Something doesn't sound right: "...the air space between the generator and manifold is so small that I can barely slide a piece of paper between these components..." Here's my early 8N generator correctly mounted. Seems I have a rolled up newspaper or more width between the generator and the manifold.

    EARLY FORD 8N TRATOR GENERATIOR, TIM DALEY OWNER/OPERATOR:

    Tim Daley(MI)

    Jim Lovejoy    Posted 07-18-2020 at 23:08:37 [URL] [DELETE]        [Reply] [Email]  
  • Re: Correct 8N Fan Belt?
  • Thanks again Tim for the insight, and I have enjoyed reading the Club's historical files as well as the ones within the N Board Forum. I wish I had your expertise but then you've been associated with many aspects of the Ford Motor Co apparently throughout your life - wow!

    Looking at the purchase order completed by the Source, the part number of the belt I received is 9N8620B3. The three pulley wheels are all original so it's not like I've an oversized wheel that's taking up more belt. I guess I'm at a loss now as to why the belt is "short" but I truly am glad for you that you can get a rolled up newspaper between the two. At this point I think I'll have to go to an auto parts store to find a longer belt.

    Cheers,
    Jim

    Tim Daley(MI)    Posted 07-19-2020 at 03:33:23 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Correct 8N Fan Belt?
  • Is it possible you have the wrong generator and pulley on it? The pulley size will affect size. I'd hold off on the auto parts store visit. Part number is 9N-8620-B. When I tighten my 8N generator and belt, I use a crowbar and press against the manifold to the barrel to reach desired tension then tighten down. What are you using for the tension arm?


    Tim Daley(MI)

    Jim Lovejoy    Posted 07-19-2020 at 06:44:50 [URL] [DELETE]        [Reply] [Email]  
  • Re: Correct 8N Fan Belt?
  • Tim, I'll try again but I've a healthy fear of ruining bearings by over tightening the belt. While a crowbar would have been better, I used two stout long screwdrivers that provided good leverage. The tension is maintained by the Belt Adjusting Arm (8N-10145), the Generator Support Bracket (8N-10151-A) and of course the Drive End Plate Assy (9N-10138-C).

    Like many new 8N owners, the tractor was all but a derelict when purchased. Of the many pieces, parts, and components replaced; I did purchase a rebuilt generator from NAPA but in doing so I reused the original pulley.

    I've other questions regarding the lift points for raising the tractor, Panel Assy without hole for Proofmeter, adjustment of the Throttle Control Arm Bracket and its fit with the Throttle Control Lever Arm Assy (8N-9807), and the Drawbar Clevis Pin Assy (8N-804). Have you the time for these questions too?

    Cheers,
    Jim

    Tim Daley(MI)    Posted 07-19-2020 at 07:38:51 [URL] [DELETE]        [Reply] [Email]  
  • Re: Correct 8N Fan Belt?
  • AHA!!! A NAPA generator -didn't know they offered one but it sure ain't an OEM unit. It wouldn't have been manufacture by NAPA anyway. Like every other supplier, just an aftermarket Chinese company supplying them. What does the AMMETER show when charging? Are you using the correct VR? Did you polarize the genny via the VR? I wouldn't worry about overtightening the belt. A new belt is going to stretch out some now anyway. Mt email is open to talk further...


    Tim Daley(MI)

    Jim Lovejoy    Posted 07-19-2020 at 13:40:27 [URL] [DELETE]        [Reply] [Email]  
  • Re: Correct 8N Fan Belt?
  • It's a hot day here and in rechecking the belt tension, I've more "slack" I can take out. Maybe I can move the generator farther from the manifold. Thanks for your encouragement.

    About the original generator which I still have. I've good confidence that it's a genuine 8N part as the rearside of the Drive End Plate Assy boldly reads as 8N-10139 - not 10138 - and then is followed by 4 GL. It has an oil lubricating cap/port. It has three terminals for GND, FLD, and Ammeter but these letters were not marked/stamped into the housing. It does not have the Tension Assy (8N-10181) used with the 1939-1947 generator, and it does not have the Generator Support Bracket (8N-10151-C) used with 8Ns after Serial 263844. Should the generator have either for this 1949 8N Serial 214385? The generator is blue not that it matters much. I wouldn't put any money on whether it's a 2 brush or 3 brush.

    About that NAPA generator. With the exception of the oil lubricating cap/port which is absent and the GND & FLD letters being stamped into the housing, the NAPA is externally identical to the original. The NAPA generator was rebuilt by the Wilson Company which is a subsidiary of BBB Industries and with headquarters here in the US. My hunch is that this rebuilt part is genuine 8N part too but I've no plans to open it.

    About the ammeter, it's new but it doesn't read a charge - it never has. Nonetheless, "Spry Bess" starts everytime without stutter! I'll write to you separately on this and other questions if you don't mind.

    When I purchased this tractor, it ran horribly! Besides replacing the generator on this 6v system, I tossed the old electrical harness, replaced the VR, disassembled/cleaned the starter, replaced the solenoid, coil, plugs & wires, points, condenser, resistor, and overhauled the front mount distributor. There was some other fun work too.... The 75 Tips was a great starting point, and I wouldn't have known about polarizing the generator otherwise.

    I greatly appreciate your time.

    Sincerely,
    Jim

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