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spark plug analysis..

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Old Feb 20, 2008 | 05:44 PM
  #1  
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Default spark plug analysis..

#2, 4 and 6

These were installed at the begiing of my tuning so they need to be replaced.

They are Champion RJ12YC which is what book called for.

Cross referencing them I come up with all kinds of plugs that haven't been mentioned on the forum

AC R44's cross reference with Champion RJ8C and NGK B26S and B6S. It seems the RJ12YC is 4 steps hotter than AC R44.

Regardless, how do the plugs look? (besides fouled)





Thanks,
Jim
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Old Feb 20, 2008 | 05:52 PM
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It looks like you are burning very rich as indicated by the black carbon. Do you generally take the car on very short trips? This will do it and is very hard on the engine.
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Old Feb 20, 2008 | 06:05 PM
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Originally Posted by Jud Chapin
It looks like you are burning very rich as indicated by the black carbon. Do you generally take the car on very short trips? This will do it and is very hard on the engine.

Lately, yes.
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Old Feb 20, 2008 | 06:24 PM
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i don't use a choke. do u? ditch it.
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Old Feb 20, 2008 | 07:11 PM
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Those plugs aren't 'fouled'....yet. They are blackened...indicating rich fuel mixture...but there is no accumulation of materials in the area of the gap.
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Old Feb 20, 2008 | 07:24 PM
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Put new plugs in and take it out and put your foot in it Corvettes or made to get out and run. I have a 69-350-350hp and I needed plugs so I went to autozone and the kit behind the counter looked at the plug and said is this for a tractor---GO FIGURE
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Old Feb 20, 2008 | 08:15 PM
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The 12 is very close to a 45, the 10 would be close to a 44 and the 8 is really colder than a 43.

Your plugs look fuel fouled. various reasons for that. A few degrees advance may help it. The idle may come up, but just close the butterfly's a taste to lower it.
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Old Feb 22, 2008 | 02:35 PM
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This is just my experience, but I have never been wild about Champion spark plugs. I would install a set and run the car in a time trial. They were good for maybe another week or less before the car would start to break up.

NGK’s plugs used seemed to work better for me. I would be interested to hear what others have to say about plug brand preference.
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Old Feb 22, 2008 | 03:30 PM
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Originally Posted by Matt Gruber
i don't use a choke. do u? ditch it.
It doesnt stay running if I dont...


Originally Posted by 7T1vette
Those plugs aren't 'fouled'....yet. They are blackened...indicating rich fuel mixture...but there is no accumulation of materials in the area of the gap.
I leaned it out a touch...


Originally Posted by bojangies46
Put new plugs in and take it out and put your foot in it Corvettes or made to get out and run. I have a 69-350-350hp and I needed plugs so I went to autozone and the kit behind the counter looked at the plug and said is this for a tractor---GO FIGURE
I have my '06 GTO for that...


Originally Posted by Ironcross
The 12 is very close to a 45, the 10 would be close to a 44 and the 8 is really colder than a 43.

Your plugs look fuel fouled. various reasons for that. A few degrees advance may help it. The idle may come up, but just close the butterfly's a taste to lower it.
I leaned it out a touch and put AC R45's in. 43's and 44's arent available in my area (if at all). I'll recheck my timing to see if I can put a little more advance in. I know its advanced beyond what the book calls for already.

Last edited by jim2527; Feb 22, 2008 at 03:32 PM.
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Old Feb 22, 2008 | 03:32 PM
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Originally Posted by cottoneg
NGK’s plugs used seemed to work better for me. I would be interested to hear what others have to say about plug brand preference.
NGK's and AC's are preffered. I wanted to try the NGK's but nobody near me has them.
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Old Feb 22, 2008 | 03:42 PM
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I just got sum NGK from Oreilly they had to ship them from there store in Oklahoma , but all paid for was the price $ 2.69 plus tax no shipping for a set of NGK- 2869 i got 9 of them !
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Old Feb 22, 2008 | 03:44 PM
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Originally Posted by cottoneg
This is just my experience, but I have never been wild about Champion spark plugs. I would install a set and run the car in a time trial. They were good for maybe another week or less before the car would start to break up.

NGK’s plugs used seemed to work better for me. I would be interested to hear what others have to say about plug brand preference.
100%
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Old Feb 22, 2008 | 03:51 PM
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The last time i used NGK"S Ii put a set on my 00 Trans Am ws6 and it was a pain in the *** it took me 4 hrs to change them out , but well worth it ! NGK
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Old Feb 26, 2008 | 06:12 PM
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Originally Posted by jim2527
NGK's and AC's are preffered. I wanted to try the NGK's but nobody near me has them.
I get them at sparkplugs.com

Anyone else have a better (cheaper) internet address?

Last edited by cottoneg; Feb 26, 2008 at 06:20 PM.
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Old Feb 26, 2008 | 07:29 PM
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I run NGKIX(irridi)'s on my 76 Stock(DOES NOT require GAPPING!)
6.99$ per plug but WELL WORTH every penny!
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