I would be interested in seeing your arithmetic. As they used to tell us in engineering school "no credit if you don't show your work".
In the spirit of fair play, I'll show my work first:
The energy stored in an ignition coil is the 1/2 the inductance in henries times the square of the steady-state current in amps. (E = 1/2LI2)
The inductance of a typical automotive ignition coil is 9 millihenries, although for our discussion the actual inductance is irrelevant since you didn't swap the coil. (The inductance "comes out in the wash".)
Coil energy with original resistor: E = 1/2LI2 E = 1/2L(V / R )2 E = .5 * .008 * (12 / (2.2 + 1.8) 2 E = .004 * (12 / 4)2 E = .004 * 32 E = 36 millijoules
Coil energy with new resistor: E = 1/2LI2 E = 1/2L(V / R )2 E = .5 * .008 * (12 / (1.8 + 1.8) 2 E = .004 * (12 / 3.6)2 E = .004 * 3.32 E = 44 millijoules
So your resistor swap gained you a whopping 22 percent increase in spark energy.
Questions: 1. How is it that an engine in good running condition can go from not running to running perfectly just with a 22 percent increase in coil energy? 2. Are you confident you can accurately measure resistance to an accuracy of less than half an ohm? I did this for a living for many years, and I know I can't do it unless I have a multimeter capable of performing a four-wire resistance measurement. (I'm pretty sure your meter doesn't do four-wire.) 3. Did you bother measuring the point resistance, and if so, what was it? Half an ohm resistance across the points will obliterate increased current you gained from your resistor swap.
Look forward to reading your answers and seeing your math.
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 - New Life for an Old Allis - by Tyler Woods. My friend Jon, has an old '39 Allis Chalmers B. He thought it a marginal tractor that had long since served its time. She smoked terribly and never had much power but he couldn't afford another so he was limping along with what he had. Jon's Allis has a small front loader and though it doesn't carry much, it serves his needs. It was the hard starting and low power that made him think it was time to replace the old girl. Jon called me to help him discover why his tractor wouldn't start
... [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]
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.