420 solid state ignition?

[H-D]

Lavoy cut to the chase when he quoted the wattage figure. Watts IS power! I still like the water analogy, voltage is pressure & amperage is volume. Either by itself will serve little purpose, BUT the two acting in concert is a water cannon like the riot control boys use. Do the math & figure the watts required to do the job. The 8v battery helping a gasser is probably indicating a resistance problem, the chances of its lower CCA being sufficient for lighting a diesel in cold weather is slim. You already know you have to have bigger cables to handle the amps to offset the 12v versus 6 volts. An inductive ammeter like the one Sears sold with the slip-on channels for reading battery load/starter draw & charging output/circuit draw (using big & small channels), will clearly show what's going on. A voltmeter will as well, but will require a bit more figuring. It should require a major amp 'hit' to jolt the starter into motion, but the draw should drastically diminish with rotation. If you aren't doing a restoration for competition, you might want to consider welder cable for battery cable. To me, a paint-free contact between the starter & bellhousing is a good idea as well & ground cable under a starter bolt sounds even better. Anyone ever seen cast iron wires?

[JD40c]

Heh, Lavoy. About the grounding through hydraulic system, I had something similar happen in my old Datsun Roadster. The guy that helped me drop the engine back in didn't hook up the engine-to-frame ground, and I noticed one of the regulator wires started smoking while cranking the engine. Somehow, that wire carried enough current to let the starter work, but only just.

[Lavoy]

Yes, had something similar back in my automotive days. Young gal brought in a small car, don't remember the brand. Tried to start it and stepped on the accelerator, smoked the throttle cable to a crisp. Found a bad ground cable, so I guess the throttle cable was the next closest thing.
Lavoy