Hi all,im having some trouble with my new/old engine...how do you detirmine wet fuel fouled vs oil consumption? I have a 350 chevy with a little p600 procharger...plugs came out totaly black and somewhat wet after running it for a couple of nights in the driveway. I was thinking with breaking in the cam, all the additives/ gm eos oil and idling etc might have caused the black plugs initialy, so last night I installed a new set of plugs and with only enough run time to bring engine up to temp they were all black again. I dont see fuel dripping out of boosters...(then put hat back on to finish warming up) pv is a 4.5 on primary(changed from a 6.5 to the 4.5 tonight to see if it cleared up any...actualy seems worse!)...this is also a built carb from a pro shop. will call them tomorrow as well. Can stand behind car and eyes burn...thats seems rich to me but...funny thing is throttle response is killer...idles great,engine vac is where it should be for the cam, idle mix screws if turned in will kill engine. i dont get it...where do i start looking? will a weak ignition cause such a dark plug? Im locked out at 29-30 degrees timing, can rev this thing up and hold it, its smooth, rev it, snap it, its crisp, it all seems ok just real black plugs. No smoke out of my breathers...should i be running a pcv valve somehow? Any advice? Thanks in advance!! oh one other thing, this was a short that I had a mini blower on 2 years ago..ran fine then...just put new heads on it and new cam...have just started it up a couple of days ago and broke cam in...havent changed my original oil since then....have rotella oil and gm eos still in it....could i have glazed the rings?

 

sounds like your doing a good job. Only thing I can tell you is smell and feel. Oil and fuel smell and feel completly different.
On the power valve, if it is opening and closing it will definatly affect the idle. It will bog or slow down when its trying to open. Do you have a boost gauge with vacum and boost. could tell thay way also.
My first guess would be oil. Is it a new engine break in? Old engine? Just doing some tuning?

 

hi, added more above..yes have vac and boost gauge...reads 9-10" at 1000 rpm and steady...will increase with rpm and still steady....low vac cause my cam is on a 110 l/s....thanks!

 

If you have 9lbs of vacum and a 4.5 power valve that is great. If you have just refired after a couple of years I wouldnt sweat it. change the oil and go for a ride. just keep a eye on it. Rings can be very touchy after sitting for a long time.

 

you should be able to tell if it oil or fuel. Is all the plugs fouled thw same? If it is oil it will turn "ashy" after the engine gets hot and starts to burn the oil. If they are wet you should be able to smell the difference. Fuel will stay black on the plugs and oil will turn grey/whiteish and be crusty.