1988 Turbo II, big street port with RA Super Seals, running 19-20psi on a T04S 60-1 on unleaded race gas. AFR's are in the 11's, timing advance is about 15 degrees in peak torque area advancing to maybe 18 by 8000rpm.

Here's the situation. I installed BR10EIX plugs about 400 miles ago on stock T2 ignition w/ magnecore wires, gapped to .028 . The car was hesitating some. I pulled the plugs out and looked at them and they seemed ok. So I installed an MSD 6AL box on the leading. It ran good for a little while and started to get blowout/hesitation again. So I go to remove the plugs. The front ones and the rear trailing come out fine. On the rear leading plug, my ghetto DIY thin wall socket cracks and I round off the hex of the plug (I have since acquired the expensive Racing Beat socket). So I get my friend to weld a small piece of pipe to the hex that I could turn to get the plug out.

When I pull the plug, the center insulator has broken loose. You can see in the first pic that holding the plug upright it looks ok (sorry for the bad pics, it obscures color and makes it a little blurry. cell phone cam). But when I turn it upside down the insulator has clearly broken off. But the electrode is fine. The outer ring of the plug is brownish, the insulator is a light brown color, the ground strap is brownish as well.

Could this have cracked in the process of welding the pipe to the plug hex, from all the heat? Should I be worried here? Maybe it's a manufacturing problem with the plug? I'm already running more injector lag on the rear injectors to richen up the rear rotor slightly (using a PFC). Or is this the worst case scenario and the motor has experienced some kind of insane detonation? I would think the electrode would have damage as well though. It doesn't appear that anything has fallen into the engine. I have datalogged knock count but I don't trust them... I think I have a noisy engine. I've been doing mostly 1st and 2nd gear pulls on the street (with wheelspin in 1st) and haven't gotten to the dyno. I'll get 70 counts of knock just laying into it at like 5psi, then knock will stabilize in the 30s and 40s, certainly not 70 counts at high rpm/boost... I highly doubt this is detonation with 100+ octane in the tank.

Thoughts? I really hope that I just heated up the porcelein from the welding and that's all there is to it. The car seems to run and idle ok, pulls 14-15" of vac.

 

Not worth gettig excited about any number of ways for it to get screwed up. Replace it and check everyting and move on. Those plugs look way clean they must not have many mile on them.

Good luck!

 

The plugs are nowhere near as clean as they look. The glare from the camera's light just made it look that way... they are mostly dark brown. I am thinking it's not a big deal either. The heat from the welder immediately followed by the torque on the plug from turning it could have cracked the insulator.