Agree. I use a spark tester that you set the gap to match the coil output voltage you want to test. The stock L98 coil has no issue jumping the tester regardless of the gap I set. Spark is strong with a blue color. The delco coil used in L98 vettes is a high output coil.
Back in "the day"....I used to have a chart from a plug mfg that had spark colors and approx voltages listed...Blue being at the top, with red, yellow and white somewhere under that.....
That was back in the (state of the art 1970s) C.D.I. era...prehistoric HEI. (
Capacitor
Discharge
Ignition)...damn, I'm old enough to remember points..!:ugh lol...I was 30 before I understood "dwell"...then I realized that the defination pretty well explained it..
I Looked everywhere and did the google search and can;t find that spark chart. Plenty of plug color charts for reading fuel/air but no spark color to read ignition strenght.
I can tell you that the GM HEI is a very hi voltage system and it will generate a spark somewhere if the plug is'nt able to fire. There can be arcing in the cap between rotor tip and cap, or at the contacts in plugs on/in the distributer cap. If that system generates a charge, its gonna be
Discharged somewhere. When plug wires are damaged or plugs are fouled, that discharge takes place in or around the cap and will do damage to parts not designed to handle the arcing. Its hi enough voltage that it'll find a path.
PS
if
YOU happen to be that path.....it hurts.
Point is,
A white spark is
not hot enough to create combustion. Its harder for a spark to happen under good compression. Thats the ONLY valid reason that hi-performance motors with higher compression need a hotter ignition system. Nobody likes risking holes in piston domes from a spark thats too hot, but it has to be hot enough to jump the electrodes under hi-compression.
White is enough to make it burp but not enough to make an expolsion. A red spark may not even get a sputter.
I'd go back and inspect the module wires inside the cap, the plug in connections on the cap, and if that ign module was a replacement, you have to consider the quality if it was not delco. The module wires are famous for getting pinched under the edge of the distributer cap and creating a semi-shorted condition where some or all of the energy is grounded out before it gets to the plugs. Look for
ANY breaks in the insulation of those wires inside the cap.
I have first hand experience with the "store brand" module. My motor ran but it was like it had bad gas...hesitated, rattled and performed poorly immediately after a major tune up. Someone suggested the module brand as an issue, so I got a Delco (that cost twice as much, for a reason) and the problem vanished instantly.
Knocking is simply incomplete combustion.That can come from poor spark or poor fuel/air mix. The process of combustion is fairly precise.
That spark should be so hot that you can hear it. If not, then there ain;t gonna be a fire inside.
Is it possible that the Tach and Batt wire are crossed on the cap? With individual plugs thats very easy to do.
otfl we did have a 4 stroke dirt bike back then...almost forgot...Honda SL 350 2-cyl. Sort of an enduro thing that weighed 400 lbs but had the torque to actually tow another bike out of the woods...lol
