I have made tests with this multi spark and got multiple back fires from engine. Juha has tested also in his El Camina and had same results. It`s fine with gasoline but for some reason, it makes lots of backfires to intakemanifold with woodgas. Before and after that test I had almost none back fires from engine.
Again, good report. Your SOHC VW engine and a Chevrolet pushrod valve V-8 engines are very radically different for combustion chambers. To get the same negative results shows that like always with woodgas motor fuels actual experiences count the most.
I have found very poor results with Robert Bosch new style multiple electrode spark plugs! Failures to constisitly fire off the woodgas - this WAS on a Cherolet V-8 High Energy electronic ignition. Solved going back to a normal wide gapped single electrode spark plugs.
On different small four stoke single cylinder engines now, valve in block and overhead valve types EXCELLANT woodgas results with an American spark plug by an E3 company. These have a ground electrode with a square hollow center over the end of the center hot electrode.
Steve: That brings up an interesting question: Does woodgas want a different gap on the spark plugs vs the standard gas setting to be more efficent/powerful? Maybe Wayne or someone with a tested system can try to put down some loose numbers by swapping out a set of plugs for ones with wider/narrower gaps for a few weeks?
Plug gap is an interesting question guys. I’ve noticed while switching to WG, I sometimes get the 1 cylinder missing chug, chug effect. If I dial in a little gasoline it immediately goes running smooth, then in a few seconds (maybe stronger gas), I can switch 100% with no problem. Guess I will pull my plugs and look for an odd gap.