I looked up the BPR8ES for a solid terminal version:
it has a 5K ohm resistor that we commonly use.
It is gapped to .028", but we re-gap to the mag, Pmag or whatever...
Bob; for the record, is you engine a 7.0:1 Lycoming O-320...or?
I am exposed to a variety of Lycomings from a 7.0:1 O-290G, 8.5:1 O-320 & O-360, an 11.0:1 O-360 and a 10.0:1 IO-540 (no I don't own them all) I expect the heat range for the 7.0:1 O-290 would accept a hotter plug than the 11.0:1 O-360.
I have a set of BPR9ES plugs coming for my RV-8 with the 8.5:1 O-360. They will be fired by a Pmag, the same as you. I am using the conservative A curve
If they run too cool, I'll follow your lead and try BPR8ES.
EAA 668340, chapter 326 & IAC chapter 67
RV-8 N89SE first flight 12/26/2013
Yak55M, and the wife has an RV-4
There is nothing
-absolute nothing-half so much worth doing as simply messing around with Aeroplanes
(with apologies to Ratty)