amsterdam84 Posted April 19, 2013 Share Posted April 19, 2013 So last weekend I got the monte out of storage. Just like the month or two before I put it in, it ran ok but was missing and running very rich. It was missing while warming up until I put it into the low idle. Today I decided to check the plugs. They are gapped to around .035 and regapped them to .045. Also cleaned them up. They were absolutely covered in soot. Black as black can be. They all also smelled heavily of gas. And no it wasn't me. Cylinder 8 plug looked like this. Thoughts? I have not changed anything on my carb which is a Qjet and still believe its running too rich. I'm either thinking about changing to a Holley 1406, or attempting to rebuild the Qjet. Not sure where to get parts for that though. Quote Link to comment Share on other sites More sharing options...
black07ss Posted April 19, 2013 Share Posted April 19, 2013 That looks like oil to me Mike Quote Link to comment Share on other sites More sharing options...
amsterdam84 Posted April 19, 2013 Author Share Posted April 19, 2013 Entirely possible. Thinking valve guides? Quote Link to comment Share on other sites More sharing options...
wallaby Posted April 19, 2013 Share Posted April 19, 2013 Wow. That looks like oil fouling. Rich fuel mixture will make the plugs dark in color, but not leave much clumpy deposit like seen in your picture. You can put in fresh plugs, and ask for a hotter plug. That will help fend off some of the crud buildup. Do you have some cylinders that look different? Maybe only select cylinders need the hotter plug. Start with the fresh plugs first, and see how it runs....you may not have a carb issue at all. Quote Link to comment Share on other sites More sharing options...
amsterdam84 Posted April 19, 2013 Author Share Posted April 19, 2013 That plug is the only one that was like that. All the others were just black. I have an HEI dist as well. Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted April 19, 2013 Share Posted April 19, 2013 hotter plug and a non-fouler for now. SBC are prone to rear cyl fouling. Funny thing is I've seen them eat valve stem seals, leaks into the intake runners because of poor gasket sealing, there are a couple of reasons, another one, drain back holes allowing oil to puddle and eventually oil seeps down into the combustion chamber via worn stem seals or worn guides. Quote Link to comment Share on other sites More sharing options...
amsterdam84 Posted April 19, 2013 Author Share Posted April 19, 2013 What is the non-fouler? Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted April 19, 2013 Share Posted April 19, 2013 What is the non-fouler? It's an item you screw ahead of the plug between the spark plug and the head to prolong the life of the plug. It shields it from the oil for a longer period. It tends to help with engines with excessive oil consumption. Some say they don't work but they do. If you ever had to replace fouled plugs on a frequent basis you'll know they prolong the life of the plug a little longer. Quote Link to comment Share on other sites More sharing options...
amsterdam84 Posted April 19, 2013 Author Share Posted April 19, 2013 Honestly I have never noticed any large amount of oil consumption. Does it take a lot to foul a plug like mine or is it a rather smaller amount? Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted April 19, 2013 Share Posted April 19, 2013 I guess excessive oil consumption is overstating it. If you happen to find a cylinder that shows sings of oil use, much like the plug that you show, it could be for many reasons. Sometimes it depends on the cause, for instance if you allow the engine to sit for long periods of time without use, small amounts of oil will find their way into the combustion chamber. Eventually with wear more and more oil will start to burn slowly when the temperature of the motor is colder which will start to leave deposits on the plugs. This is often caused by piston rings or cylinder walls that are badly worn. Oil may also be pulled into the chamber because of excessive clearance in the valve stem guides, or badly worn valve stem seals. If the PCV valve is plugged or inoperative, it can cause a buildup of crankcase pressure. Allowing or forcing more pressure into or passed the rings and or valve guides or seals onto the combustion chamber. Signs of "blow-by" is a good indication of too much wear. Valve stem seals are commonly a problem in the SBC head, many of the older gear-heads used to remedy a problem commonly found with the construction of the inferior "O-ring" stem seal and would use an additional "umbrella" type of valve stem seal, just to keep the oil from entering the combustion chamber. Some machine shops now use and or recommend a "positive" type seal. Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted April 19, 2013 Share Posted April 19, 2013 I would pull the plugs and do a compression test to determine the condition of the cylinders. The readings should be about the same on all cylinders. How old are your cap and wires? Do you get a little smoke on start up after it sits overnight? That usually indicates oil leaking past guides as it sits. Just some ideas hope it helps a little. Quote Link to comment Share on other sites More sharing options...
amsterdam84 Posted April 19, 2013 Author Share Posted April 19, 2013 K then the next question is should I go with the same heat range with the bad cylinder or go up one leaving the rest the same? I'd the rest of my plugs are black would increasing the heat range of all help burn extra fuel? I know that's not what you are saying just interested in what I can do for now. I've been tempted to switch to a set of vortec heads if I can find a good price. Quote Link to comment Share on other sites More sharing options...
amsterdam84 Posted April 19, 2013 Author Share Posted April 19, 2013 I've owned the cap and wires for a few years. Bought them off a member here so not sure of the age. I'll try and do a compression test soon. Quote Link to comment Share on other sites More sharing options...
overdrive Posted April 19, 2013 Share Posted April 19, 2013 Here's a good read: Heat range is the speed at which a spark plug can transfer heat from the firing tip to the cylinder head water jacket and into the cooling system. Choosing the right heat range is crucial for high performance engines. If the heat range is too cold, the spark plug will be unable to properly self-clean by burning off carbon deposits. If the heat range is too hot, your engine could experience detonation, pre-ignition, or power loss. Most spark plug manufacturers recommend that the tip temperature remain between 500° C and 850° C. Heat ranges are designated by each spark plug manufacturer with a number. In broad terms, spark plugs are often referred to as “hot plugs” or “cold plugs.” A cold plug has a shorter insulator nose length—the distance from tip to spark plug shell—and transfers heat rapidly from its firing tip to the cylinder head water jacket. Cold plugs are ideal for high rpm engines, forced induction applications, and other instances where the engine produces high operating temperatures. Hot plugs are good for applications that operate mainly at low rpms. Because they have a longer insulator nose length, heat is transferred from the firing tip to the cooling system at slower pace. This keeps the spark plug temperature high, which allows the plug to self clean and prevent fouling. Click here to read more. Dan Quote Link to comment Share on other sites More sharing options...
amsterdam84 Posted April 19, 2013 Author Share Posted April 19, 2013 I read something similar on the Ngk website last night. I don't think I can fit an anti fouler behind my headers. Going to have to go with a hotter plug. Quote Link to comment Share on other sites More sharing options...
amsterdam84 Posted May 3, 2013 Author Share Posted May 3, 2013 Haven't been able to find the same brand plugs that I have in it so I drove it with the cleaned up ones that had been regapped to .045. Car runs much better and power has increased as well. Drove it around yesterday and today with city and highway mixed in. I will have to check the compression on the cylinders when I get a chance. Other than that all is well. On a side note while it was warming up yesterday after regapping i left the rad cap off. I noticed a lot of bubbles coming through for around 5-10 minutes then they stopped. Since then I don't seem to have the same overheating issue I had before. Quote Link to comment Share on other sites More sharing options...
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