When I acquired my 76 Spitfire it was already equipped with a Pentronix's II electronic ignition. Always looking for some edge I thought the hesitation I sometimes received at around 3K RPM might be helped with the high output coil and the Pentronix's II ignition. Since installation I've been told that it might not benefit my Spitfire due to its low compression ratio (7.6/1). But it on now and I can share some information.
A thread on the net discussed the Pentronix's ignitions. From there I located the Retro-Rockets web Site and ordered the Pentronix's II they listed for the 76 Spitfire (..141 model) and the Flamethrower II coil (45,000 volts) recommended for it.
When fitting the new ignition I was surprised to find that the
two units were different and the new unit would not fit.
(
red is the 141 II model)
Talking with Carl from Pentroinx's confirmed I needed the (147... model). The problem was they did not make it in the Pentronix II form only in the original Pentronix model. We'll to make a long story short they do now.
Several weeks passed as I waited for new unit. As I waited I repaired the rust I found on the screw holes for coil mounting bracket.
(view from
under dash)
I sanded, primed and painted the area, then replaced the bolts, washers and nuts with new stainless fasteners.
The original Lucas coil shows the two copper wings that are attached to the screw posts and allow the slide connectors to attach to the coil.
Red Ignitor to Coil +
Black Ignitor to Coil -
As I installed the new Ignitor II I broke the screw that attaches the unit. Don't do that. 3 days later I stumbled upon one of the many screws I purchased that fit.
Pictures of the final assembled units to come. On a day trip it seems this change and the new richer jets on the Weber DGV (see Weber DGV project) have smoothed out the performance. It feels very strong. Not sure which is responsible but I lean toward the richer jets. Pentronix says I can increase plug gap by .005. This should increase resistance and voltage actually generated. Updates to come.