Read my plugs

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straightlinespeed

straightlinespeed

Sometimes I pretend to be normal
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Looks a little lean to me , but not bad.

I'd leave them in awhile longer , how did you adjust the carb mixture?
 
^ X2 Melted electrode of top plug suggests a little lean. IMO, 1, 2, 7, 8 plugs are more likely to be lean due to longer intake runner length. Very good, especially for first trial.
 
That is a pic of the same plug, I just turned it, to help with seeing the whole plug. I also zoomed in on it. Looking at it in hand that little knick in the electrode is very small. I didn't notice that until you pointed it out. The other plugs I was actually just looking at the colors when I pulled them. So didn't pay a whole lot of attention to those things. I should had though. Oops.

The aluminum smear is antisieze from removing it.
 
Looks like too hot of a plug, rich idle along with lean primaries to me but it's only been 90 miles so it's a little hard to tell. :)
 
For only 90 miles of driving, it appears to have quite an accumulation of ash, or deposits on the electrode. Are you burning a little oil or using some kind of fuel additives?
 
While it does appear lean, a 90 mile trip is not the correct method for reading plugs.
 
straightlinespeed said:
So being lean, I assume I should install larger primaries?
Click to expand...


You have to determine which system was working last when reading the plugs.

It could be the idle system or main jets.

Take it out to an open road/parking lot and get it running in the main fuel system, then shut it down and pull the plugs to look at them. Don't let it idle before reading the plugs, or you will be reading what the idle system is doing instead of the main system...

Make sure that you don't get into the fuel enrichment system (power valve)....
 
TrailBeast said:
Looks like too hot of a plug, rich idle along with lean primaries to me but it's only been 90 miles so it's a little hard to tell. :)
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It does idle on the rich side and I've been trying to get that dialed in with the A/F gauge. I also swapped from 72 mains to 70's thinking it was still running on the rich side, but I'll do some more running with it to figure it out.

69_340_GTS said:
For only 90 miles of driving, it appears to have quite an accumulation of ash, or deposits on the electrode. Are you burning a little oil or using some kind of fuel additives?
Click to expand...

Nope not burning oil, and im running 91 non-oxy gas, no additive.

RustyRatRod said:
While it does appear lean, a 90 mile trip is not the correct method for reading plugs.
Click to expand...

I agree

krazykuda said:
You have to determine which system was working last when reading the plugs.

It could be the idle system or main jets.

Take it out to an open road/parking lot and get it running in the main fuel system, then shut it down and pull the plugs to look at them. Don't let it idle before reading the plugs, or you will be reading what the idle system is doing instead of the main system...

Make sure that you don't get into the fuel enrichment system (power valve)....
Click to expand...

Thanks, I'll take it out for a run and do as you suggested.

Daves69 said:
Some more reading here..................

http://www.4secondsflat.com/Spark_plug_reading.html
Click to expand...

Thank you!
 
With an A/F gauge I don't read plugs anymore unless a misfire comes up. Unleaded fuel leaves very little on the plug when well tuned. Get a colder plug, assuming your timing curve is correct tune to 14.2 cruise, 12.5 WOT.
 
I have a A/F gauge installed in the car. I think I have a exhaust gasket leak so at this moment the gauge is pretty much worthless. The gauge was sporadic, cruising at 60 it was reading 10-12. When I would kick it down to WOT, and then back to cruising it would shoot up to 13-15. So I have to get new gaskets, plus I could hear the leak from inside the car.
 
straightlinespeed said:
Karl, I would rather read those and make sure the motorboat is working properly!
Click to expand...

ROTFLMAO I'd rather adjust the knobs til its warmed up properly, then check the oil.


On a more serious note: Because the OP asked about mixture questions, literal person I tend to be, restricted my answer to that issue. For the threads (especially on plug 2) to be as discolored as they are after only 90 miles, IMO, the plug is too hot. Ideally only the first two threads should be discolored. IIRC, the farther a plug's electrodes and porcelain extend into the combustion chamber, the hotter the plug.
 
what is the plug part number, and why the super long reach, and what is the compression ratio?
 
2 Darts said:
Because the OP asked about mixture questions, literal person I tend to be, restricted my answer to that issue. For the threads (especially on plug 2) to be as discolored as they are after only 90 miles, IMO, the plug is too hot. Ideally only the first two threads should be discolored. IIRC, the farther a plug's electrodes and porcelain extend into the combustion chamber, the hotter the plug.
Click to expand...

Like stated that pictures above are the same plug, just rotated to show more detail.

I may be miss understanding but I dont understand the mixture question or statement. Im tuning for max vacuum at idle which is about 14.5 to 15.

Marcohotrod said:
what is the plug part number, and why the super long reach, and what is the compression ratio?
Click to expand...

The plug is a Champion RC12LC4. Im running magnum heads and this is the stock plug for them. Compression ratio is about 9:1.
 
2 Darts said:
ROTFLMAO I'd rather adjust the knobs til its warmed up properly, then check the oil.


On a more serious note: Because the OP asked about mixture questions, literal person I tend to be, restricted my answer to that issue. For the threads (especially on plug 2) to be as discolored as they are after only 90 miles, IMO, the plug is too hot. Ideally only the first two threads should be discolored. IIRC, the farther a plug's electrodes and porcelain extend into the combustion chamber, the hotter the plug.
Click to expand...

This is incorrect. How hot or cold a plug is had nothing to do with the depth the electrode extends into the combustion chamber. It is how deep the center electrode extends into the plug. You can have two plugs on either end of the spectrum whose electrodes are the same distance into the combustion chamber.

A picture is worth a thousand words.
 

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