TimS
Well-Known Member
Bought my Duster back after 12 years. Original Motor was swapped to a 408 Stroker. It has NGK R5671A-7 plugs installed. I’ve never been fond of NGK plugs. Anyone have an alternative they’ve been happy with?
We run the 7938 aka bkr5e plugs from your first post in approx 30,000 crate engines a year. They are a HUGE upgrade to the old 792 champions we ran in the past.Bought my Duster back after 12 years. Original Motor was swapped to a 408 Stroker. It has NGK R5671A-7 plugs installed. I’ve never been fond of NGK plugs. Anyone have an alternative they’ve been happy with?
So if I’m correct that your 5 range plug is hotter than my 7. I pulled the plugs yesterday and they have a black sooty coating on them. I cleaned and put back in. I’ll keep the NGKs but might look at a different heat range.NGK '5' heat range............except:
- if using a power adder
- circle track racing
- sustained high speed driving & carrying a load
This ^^^^^Type of fuel, Cam, compression ratio, Carb CFM, Exhaust, altitude. All play a roll in plug heat range. Only you can determine what plug or heat range works best.
Why no E3's, just gotta know?I've been an Autolite guy for decades, but I've gotten a number of the bogus Autolites in recent times...
Had issues with Champions years back, but they seem to be on the rebound now. I'm not used to their new numbering system yet...
People seem to love their NGKs, so I may be trying them next.
Don't even bring up E3s.
Snake oil.Why no E3's, just gotta know?
I have had buddies try them in late model stuff and throw engine codes. Lol (E3)Snake oil.
Mine were sooty so might try a hotter plug and see how that goes.Tim,
Yes to answer your question, NGK 5s are hotter than 7s. There will be a lot of engines running around with cold plugs [ that are not needed ] getting carboned up with soot & running poorly. Plugs have a very generous temperature working range, about 800*F, which got extended with the use of copper in the centre electrode.
It has probably been asked, what heads and compression?Bought my Duster back after 12 years. Original Motor was swapped to a 408 Stroker. It has NGK R5671A-7 plugs installed. I’ve never been fond of NGK plugs. Anyone have an alternative they’ve been happy with?
Mine were sooty so might try a hotter plug and see how that goes.
Nice observation!!..You may be too cold on plug but going up in heat range may not be the fix.
briskracing.com