Very few pics here, yet. Sparks/arcs were made between the ignition coil HV output and the coils primary ground. Weaker sparks also draw from the HV output line to larger metal objects like the aluminium shielding of the box the ignition coil is put into and the walls of which can be seen in the pics.

arcs1.jpg (10060 bytes) arcs2.jpg (4290 bytes)

hv to primary ground, 1x in air and 1x in a burned fuse

hv to primary ground, in air