So, I’m finally getting a built motor installed in my single turbo G35… my engine failed back in February and we just got around to pulling the old motor… when we were transferring the ignition coils from the old motor to the new motor, my brother pulled two of the sparkplugs (pictures of the two are attached bellow).

In your opinions, what may have caused the sparkplugs to end up like this? Could it have been fragments from the piston (my guess)? If so, what may have caused my piston to come apart in the first place?

My most recent dyno is listed below too, my car is in Blue and the Red dyno is from a 350Z that had an identical setup to mine…

Here’s my build thread for some more info on the car:
https://honda-tech.com/forums/showth...4#post45681374

Thanks!

 

That plug is like that from det. I'd speak to the guy who tuned it asap.

Is that Duke Nukem in you avatar ?

 

That sparkplug on the left looks questionable. The sparkplug on the right looks like something kissed it, and it also looks like some metal bits are attached to it.

I also cant tell if your A/F ratio is about 12.5:1 or 11.3:1 or so at 70MPH

Looks kinda lean in cruise "I think"

I would compare your tune to another tune of a similar setup too see what the ignition timing is under higher loads. Although it could have been a physical problem with the assembly of the engine... you just don't know..

 

I'd say the tune is "decent" if you only spent a little bit of time on the dyno. The plug on the right looks like physical damage (something physically hit the plug, piston?)

 

The dyno shows my car (in blue) versus a 350Z with an identical setup (the red), at 70 mph my AFR was at 12.5:1, the other Z car was at 11.3:1, both of these dyno runs were at WOT.

 

That's kinda neat, it just proves to show that AF ratio sometimes does not affect horsepower in this instance.

Still not helping you solve your problem.

 

Why would just one piston come in contact with the plug ? It looks to me like its det in that cylinder. Can you post some closer pic's up of that plug ?