Engine guru's inside PLEASE!
Engine guru's inside PLEASE! Okay here is the scenario, I have a fully rebuilt forged 347 that has about 1,500 miles on it and about 70 track passes all made this season. After going 40-50 passes and around 400 miles on the plugs I pulled them out to change them and my #5 plug had oil all over it even the threads. I found out when I had all of my valves replaced in my heads and they milled and did a valve job my original valve seals with a good 8,000 miles on them (before the new motor) were reused. Is it possible that it could be coming from a valve seal or even a faulty coil pack or injector? I am running a compression test tomorow and hope this sheds some light to the situation.
Here is the odd part, every weekend the car is still getting faster and typically pulling faster mph, now to 96 in the eigth N/A in a 3,500 lbs car. Could it be one of the fore mentioned possibilties or does this sound like a bad oil ring? And if it is a ring why does it still getting faster?
Thanks in advance for any advice, help, or previous experiences!
Here is the odd part, every weekend the car is still getting faster and typically pulling faster mph, now to 96 in the eigth N/A in a 3,500 lbs car. Could it be one of the fore mentioned possibilties or does this sound like a bad oil ring? And if it is a ring why does it still getting faster?
Thanks in advance for any advice, help, or previous experiences!
An oil fouled spark plug is caused by excessive oil entering the combustion chamber. The most common cause of this is worn valve stem guides, or badly worn valve stem seals. It can also be caused by worn piston rings or worn piston walls. If the PCV valve is plugged or not working at all it can cause a buildup of crankcase pressure thus fouling your plugs. This condition can force oil and oil vapors past the rings and valve guides into the combustion chamber. A ruptured fuel pump diaphragm can also cause oil fouled plugs. Also, coil packs DO go bad so maybe swap one over to your bad plug and see what happens. But in your case it sounds like just one cylinder is having the problem so I would start with your compression test first and see where you stand.
It sounds to me like the valve job/head work would be suspect. I have no idea why the shop would reuse the seals that only cost about $1 apiece. Unfortunately there is no other way to tell if that is your issue without pulling off the spring, hold them up with air and inspect the seals. While you are in there I would put a new set of seals in. You can just do that one cylinder, it shouldn't take much time at all.
If that old worn seal was not installed straight up and at any kind of an angle that can cause a tear in the seal. I would start there.
If that old worn seal was not installed straight up and at any kind of an angle that can cause a tear in the seal. I would start there.
