Dual Ignition - 4 plugs per cylinder
Tim,
I'm still very curious about your very innovative ignition. I recently got the Wilbur Weeks dual plug heads firing on the Johnson RS by using one trigger firing the two CD modules, but used the dual coils, wired in series, per cylinder. Your approach is different as you have dual modules and coils per cylinder, and they are not wired in series as a result. Each module charges two coils, but split between the two dual coils. Is that correct? Thus the two modules charge all four coils (per cyl). This maximizes the spark energy by maintaining the energy (saturation) to the coil that the system was designed to deliver. With a new trigger system, you could "offset" the trigger to one module slightly to get more dwell, but that might be problematic to do within the confines of the flywheel. I still am "nervious" about the "alternator" type of CD system, but they seem to work very well.
If you are doing what I think you are, this shows the flywheel magnetics are able to trigger two CD modules in parallel. The way I did the RS shows the CD module is able to charge two coils in series. Your solution is electrically superior as the energy delivered to the sparkplug is maximized. I really need to test my system at max. RPM to know I have enough saturation in the coil to produce enough spark. Wilbur ran this system with good results, so will give it a try. Otherwise I've got to invest in two more CD modules and do what you have done. Don't have pictures I can access now, but can add them when I get home tomorrow if interested.
Bill, you have a lot of experience with ignitions, what's your take? Another great project Tim!
Roger
Coils in series vs parallel - That is the question!
Quote:
Originally Posted by
Powerabout
Interestingly one system halves the pak to coil resistance and the other doubles it.
I wonder which one the pak prefers?
Tim & others,
This is exactly what's been bugging me. With the coils in series, they both see the same amount of current. This provides the same maximum current to both coils that the CD is able to provide (given the combined resistance of both coils). With the coils in parallel each coil gets half of the available current from the CD. That current may be larger, as the coils in parallel will have half the resistance of the coils in series. This may be a wash as magnetic flux is directly proportional to the current, not the voltage. I thingkthat Powerabout is asking a good question. What does the power-pac "like". Neither application is what it was designed to do. The corresponding question is which wiring (series / parallel) provides the best spark at RPM. All I know is that Freddy Webb told me that Wilbur Weeks definitley advised that the coils should be wired in series for the dual plug heads on the RS. Hey Bill, can you provide some advice on this???