help me read my spark plugs

[khan0165]

hey everyone, looking for experts to help me read my spark plugs. I've been doing some ignition tuning and the performance has generally improved. I've been experimenting with more ignition advance, and idle mixture on my Holley 750 carb. I will be rebuilding the carb and experimenting with jetting then.

These plugs are Champion RC14YC. http://www.championsparkplugs.com/resul ... c&x=43&y=6

I am running a large 0.053" gap for more spark exposure. I have a upgrade Accel dizzy, coil, and 8mm wires.
The motor has L98 58cc ported heads, with larger valves (2.00, 1.55), 10:1 pistons, and I am running 36 deg of total advance, all in at 3700rpm. I’ve tried 34 & 35 deg, but I will need to see the benefits of less advance at the strip at top end.
The Holley 750 has 73/83 jets. I am using 91 octane fuel. And a thing worth noting is, there seems to be some blow-by and I suspect the rings are getting worn.

I'll start with the right bank (1, 3, 5, and 7)
#1

#3

#5

#7

The left bank (2, 4, 6, and 8)
#2

#4

#6

#8

#2 appears wet to me, #1 is discoloured, and most others are white on strap. All plugs came out black on base.

 

[pontiacgp]

with the carbon around the base that's rich idle and it looks to be running lean after idle..

also you get more hp with a closer gapped plug....when it's on a dyno we start off with 30 and work our way up till we get the optimum gap

 

[khan0165]

is there a way to tell if they are lean from lack of fuel, or too much ignition advance (hotter chamber temperatures). If it's fuel, then I'll jet 2 up on secondaries. Should I also consider jetting up primaries?

 

[G-Body_Vet]

 

[khan0165]

lol, I've seen that photo many times... aswell, I've scaward the net for info. But many cover "general" performance tips. I wanted to post here so you guys can help me trouble shoot my tuning and possibley give me addition tuning tips.

 

[G-Body_Vet]

How old are the plugs? To be honest I didn't think they looked too bad.

 

[khan0165]

they were put on last fall before a drag event, then ran at the strip, and maybe a used for a month or so of normal driving... not old at all...
... I know they're not bad... I am reading them as an exercise to see the results of my tuning. I want to see how my tuning affected them, and what I need to do next for any improvement.

 

[MrHernandez]

...they say NGK :wink:

 

[pontiacgp]

what power valve do you have? and were those plugs removed after the engine had been idling for a while or right after a run. If it's not right after a run I think you might want to recheck them right after a hard run with as little idling after as possible

 

[khan0165]

there is definitely some idle time on there. As mentioned, they have a track day on them from last summer, then a couple weeks of driving, plus sitting over the winter. But, I have been doing tuning for the past few weeks, a few hard runs on them up and down the industrial road by my house. And a couple trips to the grocery store.

... I wanted to read them as is, because they are a good example of how my car is usually used.

however, I am starting to see that I should always maintain a couple sets of plugs, a set for usual road use, and a set for when I hit the track.