Spark plugs for a high Comp. twin plug race motor?

[Geneman]

Hi Peeps. I just had a motor rebuild. All the race goodies. Bill Condina at Xtreme did the heads and, of course removed the plugs.. so I do not know what to run and need to order now. Any suggestions.... ( trying to get this operational for the PCA club race at Lime Rock in 2 weeks..) reasonable cams, MSD ignition, 50mm PMOs, always race gas.
Thanks very much. Frank.

[gled49]

Single or twin plug? 12 or 14mm plugs or both? Please preface request with some basic info.

[Geneman]

Thanks gled. twin plug as indicated in title, I think they were either 3.0 or 3.2 heads to begin with. not sure if 12 or 14 mm but this was not altered from stock by the hand guy at xtreme

[Geneman]

head guy

[snbush67]

Originally Posted by Geneman

Thanks gled. twin plug as indicated in title, I think they were either 3.0 or 3.2 heads to begin with. not sure if 12 or 14 mm but this was not altered from stock by the hand guy at xtreme

The stock holes upper are 14mm, the bottom hole could be 12 or 14mm. It’s likely if Bill did the heads that the bottom holes are 12mm but you have to check.

NGK BPR8ES are 14mm
NGK D8EA 2120 are 12mm



Shane

[winders]

I used Brisk silver racing plugs in my engine with Xtreme heads. Both holes were 12mm so I used Brisk BR12S plugs.

[proporsche]

Originally Posted by winders

I used Brisk silver racing plugs in my engine with Xtreme heads. Both holes were 12mm so I used Brisk BR12S plugs.

i also use Brisk -since they are local Bohemian company with an excellent reputation;-)

Ivan

[Geneman]

thanks everyone. great stuff