Who came up with the NGK part number system?

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SGBARRACUDA

SGBARRACUDA

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I could probably accept using NGK and I do run a set in my 416. But, why in the hell do they have such a messed up part number? I years past dealing with Champion it was so simple. If you were using N12Y and you wanted resistor plug, simple add a R in front, RN12Y. Need a colder plug? Use a N-9Y. N denoted 3/4" reach plug Autolite was the same, running a 64 and you want a colder plug? Use 63. You have a BB use a J12Y or Autolite 85. J denoted a 3/8" reach plug. But as I just read in a slant 6 thread they were talking about a NGK zfr5n? What the hell kind of system is that? There doesn't seem to be a system here?
 
I noticed the same thing searching through NGK plugs. The heat range indicator opposite compared to other plugs as well. Exactly know what your saying.:BangHead:
 
All you need to know about NGK

ngkchart.jpg
 
Yep, ngk is really well thought out, just different.
Heat range runs the other way but r=resistor, etc.

I grew up using ngk professionally, and champion seems like the bassackward one to me.
 
ok so my NGK plugs have "GR4GP" on them..

ok so the 4 is the second hottest heat range.. not sure how to read the other numbers..
 
What in 'ell uses a plug with an 8mm thread??
 
abodyjoe said:
ok so my NGK plugs have "GR4GP" on them..

ok so the 4 is the second hottest heat range.. not sure how to read the other numbers..
Click to expand...


Some NGK plugs have more letters than others, I always start with the heat range

4 heat range, R= resistor, G= thread size, now you have the GR4, second G=? some design feature, might be in a different chart or a factory spec, P= platinum center electrode. that's my 2 cents on it.
 
I have seen an ngk with thirteen digit part numbers, and I have seen an ngk spark PLUG (singular) that cost over thirty dollars.
 
What I would really love is if all the spark plug companies finally got together and agreed on one chart/numbering system for heat range. Trying to compare heat range across several manufactures can be a pain in the *** at best.
 
Lustle said:
What I would really love is if all the spark plug companies finally got together and agreed on one chart/numbering system for heat range. Trying to compare heat range across several manufactures can be a pain in the *** at best.
Click to expand...


It would be nice but it will never happen. The worst way to pick a plug is by cross reference. There is so much leeway that the cross reference is at best a guess. The best way is to use the catalog of the plug manufacturer you want to use.

I've been tuning since 1973. I was making money by the 8th grade tuning dirt bikes. I only used Champion and still only use them. They are easier to read. And the nomenclature is much more simple. The higher the number the hotter the plug. NGK is backwards.
 
yellow rose said:
It would be nice but it will never happen. The worst way to pick a plug is by cross reference. There is so much leeway that the cross reference is at best a guess. The best way is to use the catalog of the plug manufacturer you want to use.

I've been tuning since 1973. I was making money by the 8th grade tuning dirt bikes. I only used Champion and still only use them. They are easier to read. And the nomenclature is much more simple. The higher the number the hotter the plug. NGK is backwards.
Click to expand...

That's what I mean. Cross reference's for spark plugs are a nightmare. Good luck ever really figuring out which plug corresponds to which. I've run champion and autolite in my 340. Never noticed a difference between the two. Which reminds me. Gotta get new plugs for the new distributor!
 
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