read my plugs
Thread Starter
Drifting
Joined: Apr 2006
Posts: 1,911
Likes: 2
From: gold coast queensland
read my plugs
they have been in the car for about 12 months. driven once or twice a week. the plug colors in real life are pretty close to how they came out in the pics. the threads seem to be an oily black but the centre and side electrode seems quite dry.
Pro
Joined: Dec 2006
Posts: 665
Likes: 0
From: wilmington nc
What you look for is where the ground strap changes color, it should be at the 90 degree bend. You also look at the bottom of the porchlin (sp) way down inside the plug, a maganifing glass will help see down in there along with some good lighting. Now don"t go get in trouble, but the car needs to be run at full throttal for 1/8-1/4 mile then shut the engine off. Then read your plugs. If your car idled for 1-2 minutes before you shut it off your only looking at your idle mixture. If you know your compression here"s a chart from edelbrock to get you in the ball park.
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Instructor
Joined: Aug 2003
Posts: 104
Likes: 0
From: Newfane NY
I see you are running split fires, Is the heat range correct for your car?
What set-up are you running (stock 350,quadrajet, open air cleaner?)and last, but not least, how long of a trip do you make?
Our cars need to be warmed up to have the choke wide open and short trips won't allow that. A trip of maybe 1 hour would be great, but short trips of 5 to 20 minutes this would be the norm for any plug.
These look pretty good, just clean them and re-install when ready and follow the recommendations based on the replies you receive...
Good luck
What set-up are you running (stock 350,quadrajet, open air cleaner?)and last, but not least, how long of a trip do you make?
Our cars need to be warmed up to have the choke wide open and short trips won't allow that. A trip of maybe 1 hour would be great, but short trips of 5 to 20 minutes this would be the norm for any plug.
These look pretty good, just clean them and re-install when ready and follow the recommendations based on the replies you receive...
Good luck
Thread Starter
Drifting
Joined: Apr 2006
Posts: 1,911
Likes: 2
From: gold coast queensland
thanks for your thoughts everyone. as most have said i also think its pretty close to being right but slightly on the rich side.yes rick the split fires are the same plugs that come in all the Gm fast burn crate motors.im running fast burn heads so i think they should be right. hope so anyway haha . these plugs were pulled out after a 30 minute drive on hiway but not very high revs, it did idle for a bit just to get in the garage .demon carb so no choke on that.i changed them out as i thought they were breaking down. i could hear a popping noise in the exhaust until it got up to temp and had a good run. when i took out these plugs i did notice a few of the pins at the top had come loose so when i put the new ones i did them up first with pliers. i dont know if that could cause a miss but i wasnt taking chances again. i have booked it in for a dyno tune this friday so i will know for sure then. it hasnt been on a dyno before so will be good to know what kind of power its at and all that.
Melting Slicks
Joined: Oct 2002
Posts: 2,317
Likes: 111
From: St Louis MO
It does appear that you could benefit from some tuning at partial throttle and idle.
Split ground electrodes on spark plugs are a gimmick which makes it appear that one will get two sparks, but the truth is that only one spark will occur. Further, the additional mass and surface area of the dual (split) ground electrode will impede flame propagation.
Save some money and get some good single ground electrode plugs.
Split ground electrodes on spark plugs are a gimmick which makes it appear that one will get two sparks, but the truth is that only one spark will occur. Further, the additional mass and surface area of the dual (split) ground electrode will impede flame propagation.
Save some money and get some good single ground electrode plugs.
Thread Starter
Drifting
Joined: Apr 2006
Posts: 1,911
Likes: 2
From: gold coast queensland
i dont think split fires are any better or worse compared to normal plugs. in my opinion when talking about all the mainstream brands they are all do the same job but when you get them continuously for free ill use them anyday . i cant save money much better then that.
Last edited by gingerbreadman1977; Feb 9, 2009 at 11:50 PM.
Drifting
Joined: Oct 2005
Posts: 1,527
Likes: 148
From: East London/SW Essex UK
Wouldn't a more accurate way to judge the rich/lean condition be to cruise at perhaps a constant 50 mph for a few minutes (once at full working temperature), cut the engine and knock transmission in to neutral and coast to standstill. And only read the plugs for main jetting after that.
Thread Starter
Drifting
Joined: Apr 2006
Posts: 1,911
Likes: 2
From: gold coast queensland
Wouldn't a more accurate way to judge the rich/lean condition be to cruise at perhaps a constant 50 mph for a few minutes (once at full working temperature), cut the engine and knock transmission in to neutral and coast to standstill. And only read the plugs for main jetting after that.
Pro
Joined: Dec 2006
Posts: 665
Likes: 0
From: wilmington nc
I would wait till after i got off the dyno, then you know the jets are correct. Do the cruise an check for color, then let it idle a few mins an look at color. I changed heat range to get good color at cruise but took quiet a bit of tweeking the carb to get correct color at idle. At this point you do not know if your looking at heat range of plug or wrong jetting. Even timing plays a part in plug color ( the ground strap will tell you if timings off). Both ngk and msd websites have good articals on plug heat range. How much compression has the engine got an what heat range are the split fires you have in there now? You also need to be aware that a new set of plugs will not change color as quick as a older set.