Im back with yet another question. I have noticed that the ring outside the electrode on my spark plugs is pretty dark, especially the #2 cylinder, I also noticed a small ammount of what looks to be oil over the threads on all of the plugs that I pulled. I have vortech heads, and the plugs are ac delco platinums. I know my motor burns/leaks a little bit of oil, but it only has about 15000 km's on it. Is this normal, or does this mean my rings didn't seat properly, bad valve seals, motor too rich.....? I'm lost here guys please help me. (any websites with pics and diagrams would be awsome aswell) ohh ya forgot to mention i did a compression test and all cylinders were from 150-155 psi.... do you devide this by 14.7 to get your compression ratio?

 

the spark plug number is 41-932

 

oil on the threads don't mean much. you might want to do a compression test and leak down test to confirm the condition of the rings and valves. oil consumption will casue the plugs to foul, like you didn't know that. hard to see much in your pics. also might want to change the heat range one or two steps.

 

yea sorry for the crappy pics, i was using my phone to take the pictures, thats all i have right now. They look a little dark to me. A local shop said that will just tell u the condition at idle unless you go for a few hard pulls and kill the motor, then take out the plugs. and truth to this?

 

In a street car it will give you a general condition of the engine. To read plugs for a straight race car you should run 3 hard pulls under load and then shut the engine off to get an accurate reading.