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Dual Ignitions

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Marc W

Well-Known Member
Joined
Mar 31, 2017
Messages
1,234
Location
Colorado
I am making new baffles for my engine and I am looking at something that has bothered me about the ignition setup for a long time. Maybe the more knowledgeable VW people can help me out here.

My Hummel 2180 has dual ignitions. It has the electronic ignition that fits in the distributor hole and the Slick 4220 mag mounted on a Diehl accessory case. The coils for the electronic ignition are mounted on the back of the accessory case. I previously made blast tubes to cool the two coils since they should be kept cooler than 180 degrees. The heads have dual plugs and the electronic ignition is set up to fire the bottom plugs. The mag fires the top plugs. I assumed that it was setup this way because the bottom plugs maybe tended to foul more than the top plugs and the hotter electronic ignition would fire fouled plugs better. However, one of the articles on engine cooling that was linked somewhere in another thread said the author fired the top plugs with the electronic ignition and fired the bottom plugs with the the mag.

I would prefer that because it makes a simpler installation. The way I would like to do it is to mount the coils for the electronic ignition on top of the engine, on the cool side of the baffles. This eliminates the need for blast tubes for the coils. Also the wires from the distributor to the coils don't have to go through the baffles. It also puts the coils on the same side of the baffles as the spark plugs so there isn't any need for plug wires to go through the baffles and it eliminates holes and grommets in the baffles for the plug wires. It just makes more sense to do it this way.

So the question is, will the engine really run better with the mag to fire the top plugs and the electronic ignition to fire the bottom plugs?
 
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