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Old 05-06-2012, 09:00 PM   #1
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Default How bad does this piston look?

So I pulled my engine apart due to a bad valve leak in cylinder 2. Once i had it apart and all cleaned up i noticed this damage to the piston in cylinder 3.

How bad does this look to you guys? It looks like it sucked up something right? not detonation?

I have not found any damage to my turbo. Cylinder 3 had less than 10% leakage and 160 psi on compression test.
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Old 05-06-2012, 09:03 PM   #2
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something definitely got in there, how does the head look?
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Old 05-06-2012, 09:04 PM   #3
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Quote:
Originally Posted by FowlerMotorsports View Post
something definitely got in there, how does the head look?
I can't find any damage to the head.... let me go take another look.
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Old 05-06-2012, 09:12 PM   #4
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Originally Posted by hochkis View Post
I can't find any damage to the head.... let me go take another look.
I lied, head shows similar damage. I'm not planning on reusing the head though.

my question is, can i use this piston or is it a ticking time bomb?
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Old 05-06-2012, 09:32 PM   #5
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Shouldn't be a problem if you clean it up. You've gotta get all the raised edges off around the divots. Take a file to it, and level that surface off without removing too much of the original surface.
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Old 05-06-2012, 10:17 PM   #6
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Looks like there is a tiny bit of scoring on the cylinder wall... couldn't really get a good picture of it. I could not catch it with my finger nail but I could feel it with the tip of my finger.
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Old 05-06-2012, 10:33 PM   #7
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Does you haz both throttle-body butterfly screws still?
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Old 05-06-2012, 10:35 PM   #8
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Does you haz both throttle-body butterfly screws still?
First thing i checked. Both are still there.
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Old 05-07-2012, 12:05 AM   #9
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How about piston rings? Those are very similar marks to what a small broken ring made on my piston..
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Old 05-07-2012, 12:12 AM   #10
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I think an rx7 injector pintle cap entered one of my cylinders like 2 years ago. Car still runs ok though.
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Old 05-07-2012, 12:23 AM   #11
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Well i think you can still run it but i wouldnt do a high boost or low octane tune. U would prob have pre ignition with them edges.

I say time to build a block
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Old 05-07-2012, 12:33 AM   #12
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Quote:
Originally Posted by elesjuan View Post
How about piston rings? Those are very similar marks to what a small broken ring made on my piston..
Can't see any ring damage, but the pistons are still in the block.
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Old 05-07-2012, 01:38 AM   #13
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not as bad, but I'm still using this head.
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Old 05-07-2012, 01:51 AM   #14
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Yeah i'm going to use just the bottom end. Have a rebuilt head sitting on the shelf ready to go on. Just need to replace the rear main seal and clean up the block. Thanks for all the help and suggestions.
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Old 05-07-2012, 11:26 AM   #15
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it looks like a flaked ring, I would pull that piston, and check the rings out.

If it all looks good, slide it back in and go on with it.

Dress the sharp edges off like has been stated above.
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Old 05-07-2012, 03:52 PM   #16
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Would it be ok to pressure wash the engine with the head and oil pan off, and the rotating assembly still in? It won't hurt anything right?
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Old 05-09-2012, 01:25 PM   #17
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Nope, as long as it dosnt sit up too long and rust.

Build it and get oil in in asap and get it primed.
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Old 05-14-2012, 10:23 PM   #18
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Any imperfection will cause a hot spot and more detonation.
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Old 05-15-2012, 11:34 AM   #19
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Quote:
Originally Posted by blkmkiii View Post
Any imperfection will cause a hot spot and more detonation.
Unless time and care is used and any high spots removed.
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