Thread: way richer, plugs still look lean

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I had plugs in my engine with a heat range of 44 initially and the edelbrock metered as it came in the box. The plugs looked lean as hell so I went to cooler plugs and went 3 stages richer in power mode and 2 stages richer in cruise mode.
I looked at 2 plugs last night after a 60 mile drive this weekend and I wouldn't even know the plugs have been used.
Shouldn't these things be slightly brown?
what gives.

without lead in gas it is sometimes hard to read them by looking at them

I used some lead substitue actually, but I don't know how similar to lead it really is.
But still, the first time with the leaner jetting and hotter plugs they looked real bad. They were all chalky.
Now they just look like they weren't even used. If it wasn't for a slight change in texture on the ground strap I could put them in a box and say they were new. The porcelin was SPARKLING.

What ignition system are you running?

msd 6AL

I'm running the 6A, so same one really. Have you messed with the spark plug gap like MSD recommends? I was way rich, or so I thought. I opened up the gap as MSD recommends and they got better. However, you may have your gap too large.

Originally posted by DennyW
Show us a picture of them, or one. Sounds like you are right in the zone. Do change anything yet.

sounds like its right to me.

what cid are you running & what size carb? Cam? Intake?

I set the gap to .050.
It is a 402.
226 @ .050 single patter hyd.
650 edelbrock thunder carb
dual plane intake

I put about 80 miles on it again yesterday so I'll pull a plug again this afternoon and post a pic then.

in order to check plugs don't you have to go out and run for awhile and shut down @ like 2500 rpm and check plug THEN?

pic of plug

I'm not sure where the oil is from.

I'm really surprised that this thing is still lean. I'm using just about the richest metering in the carb as possible.
I can still go a little richer though.

ride around with a vacuum gauge attached for a while
this will give you a good idea where the vacuum goes
under a range of driving conditions
then adjust the metering springs so the power step
comes in sooner or later
I suspect your seconday jets will have to be upped also

Your set-up requires 756.0764 cfm for opitum performance. Take a 750 and step it up one jet size from stock on the primary side.
Your taking a chance on your exhaust valves matching the electrode on that plug by running too lean.

how did you arrive at 756cfm?
I called edelbrock when I was deciding and they told me to use the 650.
This engine is mostly stock and I don't EVER plan on seeing over 5000 rpm's.