Originally Posted by CalgarysFool
Along the same line as doubling up, I wondered if there would be any advantage in modifying the head to take 2 spark plugs. Some bikes, like BMW, have dual spark plugs.
I thought it might, for example better ensure complete fuel burn.
Say, I know just the guy who could machine such a cylinder head . . . (Jim?)
I may be full of it, but in my experience, dual plugs are used for two reasons- One, to have dual ignition, proven to not be optimal on either plug. That is to say, the plug(s) can not be in the best place, and mostly used so if your first ignition fails, the second set will keep you from landing in the middle of a playground, or woods. (aircraft)
Second, two plugs, one wire, used to swith over to the "good plug" if you foul the first. (how good can a non sparking plug be if the one that was lit fouled? Who knows, the design went out in the 70's as far as I know.)