246 Spark plugs?

I was using NGK BPR8EVX (resistor plugs with platinum tips) with the Dinoplex factory setup, gapped to 0,025.
Changed the ignition setup to a Mallory Hyfire 6AL with Mallory E-Coil 30440 CDI ignition/MSD helicoil cables and now use NGK BP8ES (non resistor plugs with standard copper tip), gapped to 0,048.

My recommendation would be to using platinum tips (BPR8EVX) with the Dinoplex or inductive ignitions, the small tips helps a lot inducing the spark with a weaker ignition system (which reduces fouling).
With a powerful CDI ignition such as MSD 6A or Mallory Hyfire 6A you want to go with standard copper tips, they propagate the multiple sparks better due to the flat tip plateau and have a longer life than platinum tips, which can be really eaten up by CDI ignitions.

 

I also had good results with the NGK, using the BP8ES, and then the BP10ES when I rebuilt with high compression pistons. (FYI, with ngk, the higher the number, the colder the plug: most other manufacturers do it opposite).

 

NGK Iridium or Platinum plugs last forever (>40,000 mi.) with a standard coil. My Dinoplex has been swapped out for a Perma-Tune box. No other changes. I use 7 heat range for general driving. 8 is a little colder. Maybe better if you push things or have hi compression pistons. Gap anywhere between 0.025 and 0.030". CD/Multi-Pulse ignitions are harder on plugs and want a larger gap. Precious metal electrodes are not necessary. Resistor is good if you have a radio. Also cuts down on erosion. Use metalic wire plug leads.
Forget Champion plugs. 2500 miles and you have to throw them away.
John

 

John,

I just PM'd you

Steve

 

Here is a great thread with details and link to Corbanis' photos that clearly show the difference between modern and older spark plugs - quite revealing!

http://www.ferrarichat.com/forum/showthread.php?t=99252