ceslaw
Just a thought and I don't see it mentioned. Is it smoking from the exhaust at all. Do you see an oily film on the car after where the exhaust exits? Sounds to me like you are getting a lot of
oil in the cylinder and it is trying to blow by the spark plug threads. If there is no
oil trail from the valve cover to the spark plug, that would be where I think it is coming from. Could an
oil ring be cracked or maybe someone did not rotate the rings correctly at assembly (so they are not lined up at the splits)? Hopefully it is none of things and maybe you could replace the valve seals on that cylinder and that will be it.
I new a guy that had a sprint car and he bought a used set of heads from RCR. They were told that they came off of Dale Sr's car. This was about 12 years ago. They put the heads on the car and fired it up and oil was just pooring out the exhaust. The found that the head was cracked in the intake cavity on #8 cylinder.
Terry