anyone know how to read sparkplugs?
#1
anyone know how to read sparkplugs?
pics of my spark plugs, trying to figure out if im still running rich/how the engine is from the plugs. originally the car was INSANE rich from my motor swap but ive gotten it to run pretty good. still smells alil rich to me. the plugs were covered in black carbon originally from the startup but i cleaned them and put them back in.
this is how they look now with about 30-40miles on them. they smell alil like gas.
this is how they look now with about 30-40miles on them. they smell alil like gas.
#2
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Join Date: Oct 2008
Location: Temple City, CA
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Car: 1990 Camaro RS
Engine: V8 305 TBI
Transmission: W/C T5
Axle/Gears: 3.08
Re: anyone know how to read sparkplugs?
A lot of carbon build-up is a sign of oil consumption/burning.
Probably bad valve seals.
Probably bad valve seals.
#3
Moderator
Re: anyone know how to read sparkplugs?
http://www.4secondsflat.com/Spark_plug_reading.html
#1 Is a timing indicator, you'll see a definite color change on the ground strap, it doesn't show well here but you can still see it right about at the arrow. Too much timing and the color change will be very close to the threaded body of the plug, too little and it'll be closer to the tip. Ideally we want it right in the apex or center of the 90 bend on the ground strap. This plug shows too much timing for the combustion chamber efficiency or octane level.
#4 Arrow shows another indicator of timing, you'll usually see a brown ring right at the tip of the porcelain area it should be a sharp and defined ring about .020 wide. Wider indicates not enough timing and any smaller , or only 1/2 way around or nonexistent as in this image is the second indication of too much timing in the motor.
#2 The tip of the ground strap is loaded with OIL deposits, fuel deposits are usually flat black in color and almost like a fine powdery deposit, this motor is leaking oil into the combustion chamber, bad valve guides, leaking valve covers allowing oil to seep through the plug threads, whatever it needs to be fixed.
#3 The threaded portion of the plug gives you the heat range, look at the threads you'll see that a few toward the tip are a dull burnt looking color the rest are black and shiny. You want about 2 threads showing the heat on the end of the plug and the rest of the threads to be shiny, this plug is impossible to read because of the oil mess. If you using a longer reach plug than this one 2.5 to 3 threads is optimum.
To increase the number of burnt threads increase the heat range of the plug, if you have 4-5-6 threads burnt you need to get a colder plug.
#1 Is a timing indicator, you'll see a definite color change on the ground strap, it doesn't show well here but you can still see it right about at the arrow. Too much timing and the color change will be very close to the threaded body of the plug, too little and it'll be closer to the tip. Ideally we want it right in the apex or center of the 90 bend on the ground strap. This plug shows too much timing for the combustion chamber efficiency or octane level.
#4 Arrow shows another indicator of timing, you'll usually see a brown ring right at the tip of the porcelain area it should be a sharp and defined ring about .020 wide. Wider indicates not enough timing and any smaller , or only 1/2 way around or nonexistent as in this image is the second indication of too much timing in the motor.
#2 The tip of the ground strap is loaded with OIL deposits, fuel deposits are usually flat black in color and almost like a fine powdery deposit, this motor is leaking oil into the combustion chamber, bad valve guides, leaking valve covers allowing oil to seep through the plug threads, whatever it needs to be fixed.
#3 The threaded portion of the plug gives you the heat range, look at the threads you'll see that a few toward the tip are a dull burnt looking color the rest are black and shiny. You want about 2 threads showing the heat on the end of the plug and the rest of the threads to be shiny, this plug is impossible to read because of the oil mess. If you using a longer reach plug than this one 2.5 to 3 threads is optimum.
To increase the number of burnt threads increase the heat range of the plug, if you have 4-5-6 threads burnt you need to get a colder plug.
#4
Re: anyone know how to read sparkplugs?
thank you IROCthe5.7 thats what i was looking for.
what can u read from my plugs. car was started first time with stock350tpi chip set to 22lb injectors, but i had 30lb SVO's on this 383, car was so rich i couldnt be in the tent with it bc my eyes burned so badly.
I kno there is no oil deposits, i kno it looks shinny but i think that might be gas, plugs have a slight gas smell to them. I tried to clean them up (they were covered in black from being wayyyy rich) my spark plug cleaner sucks so i had to use a wire brush. and i didnt get it all off. my ground strap seems to be the same on the whole thing. so what does that mean? it doesnt even seem that i have that line u talk about in #4. Its pretty obvious that i dont have any burnt threads on the plug... they were installed in my aluminum heads with a generous amount of antisieze... which is why they are that gray/silver color. but that non threaded lip is burntish lol. These accels are the 3/4" long reach plugs bc thats what the aluminum heads require... i checked them with the heads off and they fit perfectly. no threads show in the chamber when fully threaded in. what do you see from the plug?
I have 112 miles on the engine with these plugs and they were cleaned about 30-40miles ago. This is how they look with 30-40miles on them since there cleaning. I feel like it could be a bit rich but i had to bump the MAF tables since i had a slight hesitation when i stomped the throttle (a bunch of AE and slight MAF increase fixed that) i think my car just likes to run rich...idk.
kkingsrulee... its not an oil leak, heads are BRAND new patriots with new viton seals, not burning any oil in the exhaust etc.
what can u read from my plugs. car was started first time with stock350tpi chip set to 22lb injectors, but i had 30lb SVO's on this 383, car was so rich i couldnt be in the tent with it bc my eyes burned so badly.
I kno there is no oil deposits, i kno it looks shinny but i think that might be gas, plugs have a slight gas smell to them. I tried to clean them up (they were covered in black from being wayyyy rich) my spark plug cleaner sucks so i had to use a wire brush. and i didnt get it all off. my ground strap seems to be the same on the whole thing. so what does that mean? it doesnt even seem that i have that line u talk about in #4. Its pretty obvious that i dont have any burnt threads on the plug... they were installed in my aluminum heads with a generous amount of antisieze... which is why they are that gray/silver color. but that non threaded lip is burntish lol. These accels are the 3/4" long reach plugs bc thats what the aluminum heads require... i checked them with the heads off and they fit perfectly. no threads show in the chamber when fully threaded in. what do you see from the plug?
I have 112 miles on the engine with these plugs and they were cleaned about 30-40miles ago. This is how they look with 30-40miles on them since there cleaning. I feel like it could be a bit rich but i had to bump the MAF tables since i had a slight hesitation when i stomped the throttle (a bunch of AE and slight MAF increase fixed that) i think my car just likes to run rich...idk.
kkingsrulee... its not an oil leak, heads are BRAND new patriots with new viton seals, not burning any oil in the exhaust etc.
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