Dwell is the amout of degrees of distributor rotation that the points are closed. Dwell is usually close to 50% of the allotted time for each cylinder. The larger the dwell (kettering) the longer the coil is turned on and the greater the saturation of the buildup of magnetism in the coil body. As RPM increases, the time allotted, in milliseconds, decreases. If 8 cylinders in a car turning 4500 rpm are discussed we can see that the saturation time per spark goes way down. But !!! the % of on time remains the same at about 50%. Thus the coil heat buildup is the same at all speeds except stopped. When stopped, the coil is almost always on if the key is on. Thus burning up the coil because its duty cycle is 50%, not 100%. Mags need rotor speed to make sufficient voltage when hand cranked (essentially no rpm) and thus must have an impulse coupling to hold back, then release the rotor so it spins as fast as the tractor Idle speed or more. at that RPM the energy is saturating the primary windings and coil very well. Thus the magnetism is sufficient to build magnetism in the coil laminations and throughout the secondary windings such that when the points break, the collapse is sufficient to build voltage till the resistance of the gaps is overcome. Remember that at higher RPm the time for saturation buildup is reduced for both Kettering and mag systems. I hope this helps. Jim
Upload one or more videos to your post. Photo filesizes should be less than 300K and Videos, less than 2MB. Formats allowed are gif, jpg, png, ogg, mp4, mov, and avi. Be sure to use filenames without spaces or special characters, and filetypes of 3 digits lower case.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Listening to Your Tractor - by Curtis Von Fange. Years ago there was a TV show about a talking car. Unless you are from another planet, physically or otherwise, I don’t think our internal combustion buddies will talk and tell us their problems. But, on the other hand, there is a secret language that our mechanical companions readily do speak. It is an interesting form of communication that involves all the senses of the listener. In this series we are going to investigate and learn the basic rudimentary skills of understanding this lingo.
... [Read Article]
Latest Ad:
2022 John Deere 5045E, 4wd, front end loader and 3rd function with grapple. 120 hrs, 55k new, must sell
[More Ads]
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.
