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Author Topic:   Spark plug aluminized ?
Dirt Roller

Total posts: 7
posted June 05, 2002 10:01 AM
Two weeks ago my 350 Olds street stock started missing, 7 of the plugs were good possibly a little rich, but the # 7 plug was completely missing the center electrode, the ceramic was still there and the top curved part looked OK but there looked like there was some aluminum build up on the plug. I checked the compression and it was OK I put a new plug in and ran it this week and it ran fine but when I pulled that plug out to check it there was a small amount of aluminum starting to build up on it again.What is causing this? the engine runs at 180 during the race and may heat up to 220 on the scale after but no higher, engine is flat tops with 2 bbl Holley. Any help would be appreciated.

Dirt Freak

Total posts: 346
posted June 05, 2002 11:02 AM
sounds like that hole is running WAY too lean (that aluminum is piston). I would look for a manifold leak at the head (on that cylinder).

Dirt Forum Champ
Total posts: 564
posted June 05, 2002 08:57 PM UIN: 25419780
I agree with c21 check for a vacuum leak.

Dirt Full Roller

Total posts: 51
posted June 05, 2002 10:27 PM
Also might check timing. Won't live long that way tho.

Dirt Freak

Total posts: 467
posted June 05, 2002 10:34 PM
With the porcelain missing from the center , I would take this as a sign of severe detonation in that hole , whether caused by a lean situation or ignition problem . Same with the small little ball's of aluminum your seeing on the electrode . Pull the head off and see if your missing part of the top ring land . I'd then go through the ignition system , and see what you can find , especially if you have added anything new to the system . Generally if you are lean enough to burn a piston , you will see a good coating of aluminum on the plug . But detonation will blow the porcelain out of the plug , and leave small aluminum deposit's on the electrode . First thing to do , find out the cause of your pre-ignition .

Hendren Racing Engines
Rutherfordton , NC

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