ACDelco spark plugs, or are they?

[achris]

Putting a 350MPI back together yesterday, and I came across something 'interesting'...

Had a look at the spark plugs.. ACDelco, as per supplied by Merc... But on closer inspection, this.....


That is an NGK number. It appears that ACDelco don't make their own spark plugs. They're re-branded NGKs.... :laugh:

Just thought you'd be interested....

Chris.........

 

[QBhoy]

Cheers Chris. I recently found the same thing. There are a few makers making a plug with a itr4a15 mark. The NGK ones are 5599 or something and are true iridium plugs, as per the spec
the ac delco itr4a15 ones are only platinum sometimes. Much cheaper though. Or at least sellers are advertising them as such. I ordered the ac delco ones the other year (993 I think). Didn’t seem as good as the genuine ngk 5599’s. Didn’t seem as sharp through the rpms. I’m due a set this year and will be biting the bullit with the ngks

 

[Scott06]

Interesting , I had an NGK in my Sienna drop the center electrode. For a couple minutes I thought a needed a new engine as it clacked like crazy, eventually the electrode beat itself out of the engine. Never bought another ngk after that...

 

[poconojoe]

Quite interesting as you said. So I took a look at my old recently replaced plugs which I happened to replace with NGK BPR6EFS. My old AC-MR43LTS do not have any inscription on their base as yours do.
Maybe it's something new. My old AC plugs were from two seasons ago.

 

[QBhoy]

Is that itr4a15 defo specifically an NGK number Chris ? Like I say..the NGK plugs for these are 5599’s NGK numbers. The itr4a15 is on a few different brands of plugs I think. You’re probably right and they are just rebranded.

 

[QBhoy]

You’re spot on Chris. Here in black and white.

 

[achris]

.... I’m due a set this year and will be biting the bullit with the ngks

You do realise that the iridium plugs are good for about 10 years....

Chris.....

 

[QBhoy]

I know they are good for a good while Chris. It’s been over 300 hours on them and 3 seasons of 2 stroke winterising...added to this the miss firing problems I’ve had all year too. Due a change now.
But yeah, I know you don’t need to change every year. Just that mine are due.

 

[aimlow]

If you have a flat topped distributor, the plug gap has been revised to 0.038". This reduces the voltage necessary to fire the plug, and reduces the tendency for crossfire in those crappy distributor caps.