NGK spark plugs wrong size and gap!!!

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So I got my ruthenium spark plugs from an authorized NGK source (ngk.com). I got the right part number (verified several times and with tech). When I went to do the job I compared the old to the new and the NGK plug is several mm taller...wtf? This can’t be normal, can it?

0713AF2D-422D-413B-A54B-51223C31A808.jpeg 7F6A0DD1-111F-4067-B554-B46066D1DB7C.jpeg

8D6C2E64-0517-4D47-BFDA-C6C7DD5881A1.jpeg 79AE8EB2-5FF3-487C-B642-AEEBA0F851C7.jpeg 0713AF2D-422D-413B-A54B-51223C31A808.jpeg 7F6A0DD1-111F-4067-B554-B46066D1DB7C.jpeg 79AE8EB2-5FF3-487C-B642-AEEBA0F851C7.jpeg 0713AF2D-422D-413B-A54B-51223C31A808.jpeg
 

B E N

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Looks like the shanks are the same length but the new plugs have more porcelain protrusion which means longer grounding straps. So either they are a different heat range or the different electrode material has different thermal conductivity so more exposure requirement. Also those new plugs have that little element that protrudes from the strap, which pushes the strap out even further.

If they are the right heat range I wouldn't sweat it, gap them, install them and forget about it for the next 100k.


I have never had a set of plugs come out of the box with perfect gaps....
 

MTF

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It's longer at the threaded end by quite a bit if you look at the second picture.
Looks like about an 1/8" longer, from seat to tip.
don't know if it would be a problem though if it stuck an 1/8" more into the combustion chamber.
 

B E N

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Measurements with a set of calipers would be a lot more useful, second to last pic they look like the same length.
 

goblues38

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i was always taught that every plug you ever buy will have the wrong gap and you have to set it before you install.
 

MTF

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True, now I'm not sure if he gaped them before the pictures.
It's a little hard to tell if the gaps are close, it could be the new one is slightly opened but your not making up an 1/8"

OP needs to put a ruler in-between the two spark plus, measuring from the seat (only threaded part) to tip. And both gaped the same.
 
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