|
Farmall & IHC Tractors Discussion Board |
Re: Re: Re: Re: Re: Re: Farmall H Electrical System
[ View Follow Ups ] [ Post Followup ] [ Return to Forum ]
Posted by Andy Martin on September 26, 2000 at 20:32:05 from (38.31.74.106):
In Reply to: Re: Re: Re: Re: Re: Farmall H Electrical System posted by ltf in nc on September 26, 2000 at 19:31:03:
Yeah but, amperage and wattage of a motor are also based on the horsepower being consumed. I have to believe that the 12v setup will take more horsepower out of the starter than the 6v because the engine is turned faster. So the load does change, the requirements on the starter change. If you put fewer teeth on the bendix for the 12v case to turn the engine at the same speed as the 6v, then the amperage should be roughly half. If the torque required to keep the engine turning at cranking speed is independent of cranking speed, and the 12v supply turns the starter under load at twice the speed of a 6v source, then the wattage or horsepower would double for the 12v case: double the hp and double the voltage so the amperage remains the same. I can't see that the torque required to spin the engine twice as fast would be only half the torque required for the slower speed. As I said before, the bearing drag probably is relatively independent of speed, but the engine compression components (valves, rings) probably work better at higher speed, so the torque may go up. I think it takes no more than 50# pull on a 9.5 inch radius crank to turn over an H fast enough to start, and that is only 40 ft-lbs. If it takes you 1/4 second to pull up 1/4 turn (a good snap), you are cranking at 1 rev/sec. So your manual cranking hp is only 40/550=.073 hp. My recollection is that a strong man can put out 1/6 hp, and .073 is roughly 1/12, so it seems reasonable. 885ft-lbs/sec would equal 1,118 lbs pull on a 9.5 inch crank at 60 rpm (1/sec), or 280 lbs if you could spin it at 4 rev/sec. A strong man indeed. But both the man and the starter can start the engine. The man, however, is not in danger of moving the tractor if it is left in gear: the starter is much more powerful. For sure we agree that 12v is not bad for a 6v starter! And please don't take offense by my discussion, I guess it's my 4 cents worth
Follow Ups:
Home
| Forums
Today's Featured Article -
Harvestin Hay: The Early Years (Part 2) - by Pat Browning. The summer of 1950 was the start of a new era in farming for our family. I was thirteen, and Kathy (my oldest sister) was seven. At this age, I believed tractor farming was the only way, hot stuff -- and given a chance I probably would have used the tractor, Dad's first, a 1936 Model "A" John Deere, to go bring in the cows! And I think Dad was ready for some automation too. And so it was that we acquired a good, used J. I. Case, wire tie hay baler. In addition to a person to drive th
... [Read Article]
Latest Ad:
Sell 1958 Hi-Altitude Massey Fergerson tractor, original condition. three point hitch pto engine, Runs well, photos available upon request
[More Ads]
Copyright © 1997-2024 Yesterday's Tractor Co.
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V. Yesterday's Tractors - Antique Tractor HeadquartersWebsite Accessibility Policy |
|
