Larry 58 Burb, I hope this thread hasn't made you cynical about blueprinting and balancing. Both procedures are most beneficial and a very good investment, when honestly done. Therein lies the rub. Mr Coilover, Twin plugs are typically very beneficial. Aircraft engs have almost always had them w/ separate mags,especially as redundancy. Mags I've tested have a prox 1/2 milsec duration. Not long enough to create a large flame front. Especially on old low C. R. non turbulent chambers. Dual plugs were almost necessary. I still build aught year T Head engs like Pierce Arrows and some Marine units. Todays ignition systems have longer spark durations, prox 2 mil sec. That starts a good burn. It can be seen in exh temps and exh gas analysis. You can adjust spark duration w/ changes in plug wire types, rotors and plugs to work best w/ your chamber shapes and induction variables. Lots of fun.
Mr Lincoln, FYI, There are many times an inline 4,6,or 8 cyl crank absolutely needs to be bobweighted for balancing. David
