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Discussion Starter · #1 ·
Hello all,
Can you take a look at these plugs and tell me what’s going on? I just installed them and have only idled this freshly rebuilt and already broken in cammed 383 stroker. The strap is shinny black. The center electrode is flat black. These are brand new Autolutes 3924. I was fighting a very rich stinky idle with this AED Holley 750 DP, but fixed it and trashed the old fouled plugs. I’m running MSD 6A and a lot of timing at idle. 36 degrees.
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Discussion Starter · #3 ·
I’m still running breakin oil. I will drive it around. These are autolite 3924. I was thinking of switching to NGK. Where could the oil be coming from? The engine was just built by a reputable builder.
 

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Race it, Don't rice it!
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I’m still running breakin oil. I will drive it around. These are autolite 3924. I was thinking of switching to NGK. Where could the oil be coming from? The engine was just built by a reputable builder.
Rings, valve guides, intake manifold are most likely suspects.
A leakdown will give you a good idea on ring conditions. When the holes prepped right, the rings should have seated by the time you were done with the valve lash.
You may have to to put a good load on the engine for a little bit in order to get them wearing in well.
 

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Too much fuel. This might have been too long of an effort to get it up and running, choke closed too much, carb or injection running rich, spark plug heat range too cold common especially with aluminum heads. Etc.

Need more details about cam heads, compression ratio, what’s mixing fuel and air, operating temperatures, what ignition system and spark plugs not to mention how initial start up and subsequence running have been.

These modern peanut plugs are pretty much shot once they look like this, start over with a fresh set and unless you’re using a Capacitive Discharge (CD) ignition like a 6AL or better get the plug gap to .030 to .040 inch.

Bogie
 

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How do you know you fixed it, as far as the over-rich idle mixture??

Still looks rich, and maybe a heat range too cold but with no WOT run time to verify it the heat range issue can't really be decided yet.

Aluminum heads?
 

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Discussion Starter · #8 ·
I worded it wrong. I meant the stinky rich eye burning smell. I fixed that. Looks like I need to change plugs to hotter plugs and drive it hard. Then check again.
 

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plugs are questionable. they won't clean up without many miles of driving, if ever. really need a new plug to determine correct heat range. the plug blaster will clean them up OK but don't use sand, get some pecan shells or some other media.
 
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