I need spark plug part #'s for 2-3 steps colder than stock for either NGK, champion, or Autolite spark plugs. If you can post the brand, part #, and heat range I would appreciate it.

Thanks in advance

Matt

 

Autolite 103 = 2 steps cooler

I'm running the 103's. Runs great NA and on the dope.

 

Thanks for the reply! Are those 2 steps or 3 steps colder? The only reason I ask is because 106's are listed stock and the 103 are 3 steps down from stock.

BTW I found NGK R5724-8 plugs on thunderracing for a 3 step colder than stock plug. Has anyone used these plugs? Experiences with them?

Anyway keep the #'s and suggestions coming. Need the plugs to be good for a 200rwhp hit on top of my 11.5-1 engine.

Thanks again

Matt

 

Autolite 104 is 1 step colder than stock. 103 is 2 steps colder.

I don't know how many "steps" colder it is, but I use a Champion S57YC for a 275-shot.

 

Thanks for the reply fred! I'll have to find a set of those plugs and try them out for the big shots

Matt

 

When it comes down to it, the options are limitless.

You could also try an NGK R5671A-9 . Depending on the pills you use, you can change the last number higher or lower to change the heat range (Lower number is a hotter plug). 7-11 are available.

 

Thanks again Kurt. I'll let you know how it turns out. BTW, could you e-mail me that number to the guy you were talking about in the e-mail for jet size analysis?

Thanks
Matt

 

Matt, sending ya some email.......