I found this in an online text book,
"Coils operates according to Faraday's Law of electro-magnetic induction.
As the high tension voltage in the secondary winding builds up, a particular voltage level is reached when the spark plug gap suddenly becomes conductive,
The spark plug gap never suddenly becomes conductive. The distance across the air gap never changes so the resistance does not change. Electricity only jumps the gap when there is enough energy for it to jump the gap.
Yes there are factors that effect how hard it will be for the electricity to jump the SP gap.
That is why sometimes when holding a spark plug wire close to the engine and seeing a spark but the engine will not start because the coil output is to weak to fire under load in the engine.
Any way Deve's engine has no variables but points or HEI. To talk about variables has no place here. For people that put in HEI distributors did so for better gas mileage based on a better spark. All they did was change their ignition system and spark plugs. Deve is seeking to confirm that variable.
A dynamometer is not needed for Deve to put on a load. By Deve running a test at idle, then a RPM that would be used to do 30 MPH and then a test at 55 MPH will provide a load on the ignition system for at higher RPM on a stand will have more air and fuel entering the cylinders making it harder for the electricity to jump the SP gap.
Deve is working low budget trying to have fun and do an experiment. He is not doing a research paper to be presented to the SAE.
Deve will either see that there is a change in SFC or not. And if there is him not having a dynamometer will not be needed to make his findings any more valid.
A dynamometer will allow true engine load to be placed to match actual road conditions though Deve does not have to show actual SFC but only if there is a change.
