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"Burnt" spark plugs

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Old 12-22-2010, 05:07 PM
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Default "Burnt" spark plugs

Went out for a small run yesterday and once i got back i noticed that 2 plugs were burnt. pics below of one burnt and one not burnt. Also, one of the cylinders has no compression now. I think im taking the head of that side to check if the valves are closing correctly.

Any suggestions as to what may have caused this?
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Old 12-22-2010, 07:14 PM
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The porcelain has a green tint. Green=lean. Tuliped an exhuast valve or a lifted ring land is my guess. Now, why did it go lean in that hole????
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Old 12-23-2010, 07:25 AM
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it's not good....what is the engine setup ??
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Old 12-23-2010, 07:45 AM
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Looks like detonation damage, if you really have 0 compression you likely holed a piston.
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Old 12-23-2010, 09:15 AM
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Quote:
Originally Posted by Ted G View Post
Looks like detonation damage, if you really have 0 compression you likely holed a piston.
I am with Ted, Lets hope we are wrong.
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Old 12-23-2010, 10:36 AM
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All the above! or blown head gasket between cylinders,if so hopefully it didn't hurt the deck of the block..502???
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Old 12-23-2010, 12:02 PM
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What cylinders? What year?

Whey you burn a hole in piston you will see metal all over the plug and the plug will look worse than that.
I would also go with blown head gasket.

I had a problem last year with zero compression in one cylinder, it was an exhaust seat. Valve was not closing all the way.
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Old 12-23-2010, 12:24 PM
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my guess is a head gasket,was there any water in the hole?
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Old 12-23-2010, 04:15 PM
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don't think a head gasket would burn the end of a plug off like that...
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Old 12-23-2010, 05:55 PM
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no water in the hole. the pistons are new 4.530, block is a 502 bored to .06

i think that i have a combination of problems, thin head gasket (.03) hot spark plugs and low octane gas.

the oil was clean as well
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