Gerald Morris
Senior Member
That should give you plenty SNAP in the combustion chamber. Did you save the old ignition? Those old Mopar distributors can easily be rebuilt for plenty more good service.
Thoughts on oily/sooty spark plugs
- Thread starter WissaMan
- Start date
That should give you plenty SNAP in the combustion chamber. Did you save the old ignition? Those old Mopar distributors can easily be rebuilt for plenty more good service.
I still have it but probably would never reuse it. I have two or three on the shelf and any old cars I would get in the future I would upgrade to electronic ignition if they needed a tune up. I know, some may poo poo on that idea but for the couple extra bucks I like not having to worry about points, dwell, etc. There's enough to worry about with these old cars/engines 
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Small update:
After my last changes, things I have observed...
With the secondaries disabled, during an extended WOT pull, AFRs drop into the 13's and 12's but did not go below
With secondaries enabled, AFRs held in the 13's and 12's longer, but did eventually drop into the 11's and 10's. I'd estimate 4 to 5 seconds instead of 2 to 3, so that's an improvement.
Feels stronger at WOT.
Slight pinging sometimes at WOT.
A little bit harder starting after sitting and heat soaking.
Slight hesitation when cold, but more responsive once warmed up.
Pulled the worst plug and it's starting to clean up on the tip, but still oily at the threads.
I expected most of those changes since I have it tuned on the lean side and have unblocked the exhaust crossover.
I'm going to proceed under the assumption that the oil rings are carboned up and take steps to clean them up, then re-evaluate.
After my last changes, things I have observed...
With the secondaries disabled, during an extended WOT pull, AFRs drop into the 13's and 12's but did not go below
With secondaries enabled, AFRs held in the 13's and 12's longer, but did eventually drop into the 11's and 10's. I'd estimate 4 to 5 seconds instead of 2 to 3, so that's an improvement.
Feels stronger at WOT.
Slight pinging sometimes at WOT.
A little bit harder starting after sitting and heat soaking.
Slight hesitation when cold, but more responsive once warmed up.
Pulled the worst plug and it's starting to clean up on the tip, but still oily at the threads.
I expected most of those changes since I have it tuned on the lean side and have unblocked the exhaust crossover.
I'm going to proceed under the assumption that the oil rings are carboned up and take steps to clean them up, then re-evaluate.
Gerald Morris
Senior Member
Good progress. Steam clean the engine via some little mist into the carburetor in a very highly measured, rarefied dose. I plan to do likewise this weekend.
One lesson I've learned from this is that any time you buy an aftermarket carb for your engine (Holley, Edelbrock, etc.) you should probably plan on buying the tuning kit right along with it. I had to lean this AVS2 way out compared to how it came in the box. And I feel like the secondaries could stand to go even one step leaner than the smallest jet that came in the kit. Fortunately, with the Edelbrock it really easy to make tuning adjustments.
wyrmrider
Member
no time to read all the posts now but I'd have someone follow me and do the on and off the gas test looking for smoke that would most likley be rings
then change the valve stem seals they have to be toast you can get a tool to do it in the car while you have your springs off check each height with your callipers replace any short ones hp springs will have a dampner
then change the valve stem seals they have to be toast you can get a tool to do it in the car while you have your springs off check each height with your callipers replace any short ones hp springs will have a dampner
Lots of good suggestions here. However, seems like to best place to start is at the beginning. Have someone follow you and observe.
With a warm engine and transmission in 2nd run it up to redline, if you have oil smoke then you have a ring sealing issue. On the same run while keeping the transmission in 2nd let off the throttle and if you get smoke then valve seals/guides are the likely culprit. If you have smoke when running the engine up in 2nd then I would check compression again with the throttle blades open. 110 psi is pretty low. The "steam cleaning" option can clean gummy/sticking rings. If "steam cleaning" doesn't work try pulling all the plugs and spraying a carb type cleaner in the cylinders and let it sit overnight. Crank engine over without spark plugs to get rid of cleaner and any loose gunk. Either cleaning method may/can put debris in the pan so a good time to change the oil. Look closely at the oil that comes out. A good way to check the oil is with a funnel shaped paint strainer with a coffee filter inside of it to catch the small stuff. You can also consider sending a sample of the oil out for a chemical analysis. Most places that do oil analysis will provide a sample bottle. This should give you some good info as to hydro carbons, and fuel in oil. It will help to pinpoint blow-by as well as too much fuel. Once you have the foundational info and all is then it's back to carb/ignition tuning. If your not running a carb insulator it is a highly recommended option especially with todays ethanol laced fuel. Your comment regarding tuning any new carb is spot on! Congratulations on understanding that as well as your efforts on jet and metering rod changes. It is a tedious process but well worth while once you have it dialed in!
With a warm engine and transmission in 2nd run it up to redline, if you have oil smoke then you have a ring sealing issue. On the same run while keeping the transmission in 2nd let off the throttle and if you get smoke then valve seals/guides are the likely culprit. If you have smoke when running the engine up in 2nd then I would check compression again with the throttle blades open. 110 psi is pretty low. The "steam cleaning" option can clean gummy/sticking rings. If "steam cleaning" doesn't work try pulling all the plugs and spraying a carb type cleaner in the cylinders and let it sit overnight. Crank engine over without spark plugs to get rid of cleaner and any loose gunk. Either cleaning method may/can put debris in the pan so a good time to change the oil. Look closely at the oil that comes out. A good way to check the oil is with a funnel shaped paint strainer with a coffee filter inside of it to catch the small stuff. You can also consider sending a sample of the oil out for a chemical analysis. Most places that do oil analysis will provide a sample bottle. This should give you some good info as to hydro carbons, and fuel in oil. It will help to pinpoint blow-by as well as too much fuel. Once you have the foundational info and all is then it's back to carb/ignition tuning. If your not running a carb insulator it is a highly recommended option especially with todays ethanol laced fuel. Your comment regarding tuning any new carb is spot on! Congratulations on understanding that as well as your efforts on jet and metering rod changes. It is a tedious process but well worth while once you have it dialed in!
The chase car thing is a good idea. I'll get my brother to do that. One thing I do know is that there is zero oil smoke on a cold start, which by my understanding means the valve seals are decent, right? Our 68 300 with an (I assume) unopened 100k motor puts out a bit of blue smoke when you first start it. I do have a carb insulator but I'm not sure if it'll make the carb/air cleaner too tall. I checked it out today by putting some loosely wadded thin aluminum foil on top of the air cleaner and closed the hood. The foil was squished to about 3/4" tall so it will be a close fit for sure.
I ordered some cleaner, oil, and filter so I'll give it a cleaning and change the oil. Running the oil through the strainer is a good idea too. I have a whole box of those paint strainers.
I ordered some cleaner, oil, and filter so I'll give it a cleaning and change the oil. Running the oil through the strainer is a good idea too. I have a whole box of those paint strainers.
When you put the cylinders under load, as when you accelerate in a lower gear the pressure in the cylinders if rings are weak will show blow-by as evidenced by smoke. Conversely when on the other side you let off the accelerator the engine sucks air and will show up weak valve seals/ guides as smoke if they are bad. The Edelbrock insulators 3/8 to 1/2" normally won't cause hood contact. In the old days the factory used phenolic insulators. I believe the edelbrocks are wood with a rubberised coating.
ynst
Member
Looks like everyday automatic choke fouling from repeatedly starting the engine and letting it idle just to warm it up.
Also occurs every time you pull it in and out of the trailer to go to and from a car show.
Get it out and run down the street holding a steady 45 mph in second gear for a mile or two.
Pull off to the side of the road and IMMEDIATELY shut off the engine and pull the plugs and see what they look like.
If they're still oil fouled, look at the rings or valve guides.
If they were sooty and, now the carbon has burned off, drive the car more and stop starting it up every so often to let the oil warm up without taking it out of the garage (or trailer) and the sooty deposits will be a thing of the past.
Also occurs every time you pull it in and out of the trailer to go to and from a car show.
Get it out and run down the street holding a steady 45 mph in second gear for a mile or two.
Pull off to the side of the road and IMMEDIATELY shut off the engine and pull the plugs and see what they look like.
If they're still oil fouled, look at the rings or valve guides.
If they were sooty and, now the carbon has burned off, drive the car more and stop starting it up every so often to let the oil warm up without taking it out of the garage (or trailer) and the sooty deposits will be a thing of the past.
Had my brother follow behind me today and punched it a few times. He told me:
When I would punch it, nothing at first. Then a puff of smoke followed by more smoke during the pull (but less than the initial puff). Seemed to be coming only, or at least mainly, from the driver side pipe. No smoke on decel.
FYI, I've been DD this car for the last two weeks. The drive to work is 25 minutes. I've also taken it on the interstate several times running it at 70mph for about 10 minutes. I never start it and don't drive it and it certainly doesn't get trailered
I'll be doing the cleaning and oil change maybe this week and will update after that...
When I would punch it, nothing at first. Then a puff of smoke followed by more smoke during the pull (but less than the initial puff). Seemed to be coming only, or at least mainly, from the driver side pipe. No smoke on decel.
FYI, I've been DD this car for the last two weeks. The drive to work is 25 minutes. I've also taken it on the interstate several times running it at 70mph for about 10 minutes. I never start it and don't drive it and it certainly doesn't get trailered
I'll be doing the cleaning and oil change maybe this week and will update after that...
Hopefully the cleaning will help. At least you know which side to focus on. Will help you to know what compression each cylinder has. If you check compression before and after you will know if you are doing any good, and which cylinder to focus on. Do you by any chance have an H or X pipe in your exhaust system?Had my brother follow behind me today and punched it a few times. He told me:
When I would punch it, nothing at first. Then a puff of smoke followed by more smoke during the pull (but less than the initial puff). Seemed to be coming only, or at least mainly, from the driver side pipe. No smoke on decel.
FYI, I've been DD this car for the last two weeks. The drive to work is 25 minutes. I've also taken it on the interstate several times running it at 70mph for about 10 minutes. I never start it and don't drive it and it certainly doesn't get trailered
I'll be doing the cleaning and oil change maybe this week and will update after that...
Just wanted to post an update on this...
I put Kreen in the engine oil and gas tank. Did a good seafoam treatment through the carb and shut the car down and let it sit a few days to soak. Drove it til the tank needed refill, then changed the oil to Amsoil zrod 10w-30. Around that time I also tuned the carb using a wideband O2 sensor in idle, cruise, part-throttle, and WOT. (The carb had to be leaned out in all areas)
Since then I've put about 500 miles on it of average driving. I pulled the #3 plug today. It doesn't look damp or greasy and though it still is black, there is a light-gray crust on it. There is still wet oil in the threads but I'm pretty certain that's because of the leaky valve cover gaskets as I can see the heads are coated with oil below the valve covers. I checked the oil and though it's still golden colored it looks like it's down about 1/2 quart. That is a slower rate than I was experiencing before but of course it'd be nice if it was even less.
Overall, the engine is running great. No smoke, good power and mileage. Leaning out the carb really made the difference I think. Not sure if the Kreen/Seafoam treatment helped or not, but I'll probably do it again when it's near the next oil change.
I put Kreen in the engine oil and gas tank. Did a good seafoam treatment through the carb and shut the car down and let it sit a few days to soak. Drove it til the tank needed refill, then changed the oil to Amsoil zrod 10w-30. Around that time I also tuned the carb using a wideband O2 sensor in idle, cruise, part-throttle, and WOT. (The carb had to be leaned out in all areas)
Since then I've put about 500 miles on it of average driving. I pulled the #3 plug today. It doesn't look damp or greasy and though it still is black, there is a light-gray crust on it. There is still wet oil in the threads but I'm pretty certain that's because of the leaky valve cover gaskets as I can see the heads are coated with oil below the valve covers. I checked the oil and though it's still golden colored it looks like it's down about 1/2 quart. That is a slower rate than I was experiencing before but of course it'd be nice if it was even less.
Overall, the engine is running great. No smoke, good power and mileage. Leaning out the carb really made the difference I think. Not sure if the Kreen/Seafoam treatment helped or not, but I'll probably do it again when it's near the next oil change.
mr gtx
Active Member
is the plug even firing ?
Yes, they're all firing. Car runs great.
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