Would like some additional ideas. All I can tell from this is probably running rich. All of the plus look almost exactly like this. I am confused by what appears to be oil on the threads. The business end of the plug was completely dry, but the threads were wet with what felt & looked like oil, but smelled like gas (which pretty much makes sense if it's running rich). This is a fresh rebuild from last July, maybe has 2-3000 miles on it tops.
Looks like you have an oil leak in the valve covers or head gaskets. Don't think an oil burning problem would get to the threads, but you never know. Are you seeing blue smoke or using a bit of oil? Looks like a rich condition in the carb, also. Maybe a jet reduction or an internal gasket leak in carb. Hope this helps.
if this started since the rebuild, did you change anythiing like carb or different plugs. might drop a couple of sizes in the jets. if that dosen't help may need to change to a hotter plug. don't get it to lean. better to be a little rich than too lean.
the ceramic should look like the butt of a cigarrette. after taking a few puffs..... tan to light brown in color is a good color.....your ceramic looks good...could be a bit darker... put some larger rods in the carb.... the oil on the threads is a oil leak.... i would agree with the above post about leaking valve covers....
Pretty much everything on this motor was brand new, except the block, crank, and rods. I had the engine assembled by the shop that did the machine work. I thought that it was probably running a little rich but I have not ordered the metering rod kit for the carb. I don't see any oil leading from the valve covers to the plug holes, not that it's easy to see in there. I sure hope it's not head gaskets, would be pretty severe for all 8 cylinders to be leaking. Plus I would expect the plug to be oil fouled if that was the case. Also, it's not using oil and I've never seen any smoke.
Matt did you put anything on the threads such as anti-sieze compound. The residue doesn't appear to be above the plug gasket so I don't think it is a valve cover leaking. FYI if your not using anti-sieze start doing so. One day the threads may come out of the head along with the plug.
great catch, maverick1970. i always use anti sieze on my plugs. did the shop that put your engine together put something on them (such as oil) when they put the engine together or did you put the plugs in?
Yes, I did use antisieze on them, but only a light amount. There seems to be significantly more oil on the threads than what I applied of antisieze. Actually I put the plugs in twice that night, because the first time I forgot to put the antiseize on them. There were some plug valleys that did have oil laying in the bottom of them, but I could find no oil on the tops of them, which told me it could not have been running down from the top of the head. So if it's internal, why doe the electrodes appear so clean and the threads so wet? Could that indicate it's something recent?
I have seen rich plugs that look like that. I assume its just unburnt fuel in the threads. The face of the plug isnt wet because its exposed to an ignition source and it burns off into smut. The fuel pushed up into the threads cant burn because I assume there is a lack of oxygen. Im 99.9% sure its just fuel from a rich condition. My plugs always looked like that when I ran 42lb injectors.
Matt I wouldn't read a whole lot into the look of that plug unless it was pulled immediately after running at WOT...may be a little rich. Take it up to 5500 rpm in first gear and shut it down, then read the number one cylinder plug, I'll bet it will look much better. Reading the plug after running at WOT is what will tell the tale.
That is correct Take it to the track. Put your plug socket in your car. Make a pass, as soon as you get to the finish line @ WOT, let off the gas and immediately kick it it neutral and shut the car off, cost unto the return road (WAY out of harms way) and pop the hood and check the plugs. Racers do it all the time
yes but its a street car.....and can tell you the overall running .... the plugs tell me he needs a better carb
