Re: Oops
#220253
02/11/09 03:40 PM
02/11/09 03:40 PM
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Joined: Jan 2003
Posts: 18,025 S.E. Michigan
ZIPPY
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Quote:
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Both Butting of the rings and or detonation can break the ring lands. With Detonation there is usually tell tale signs as in Specking of the pistons and quench pads. I cant tell from the pics if there is any specking because of all the scrappnel damage. But there could be. mike
Too tight of ring gap is a good point. The "good" pistons that are left in it (that didn't have any shrapnel hit them) don't show any signs of specks taken out of them. So the rings probably butted together, then?
if the bearings are hammered and fallout of the caps, it was detonating. it's very possible that detonation AND the rings butting together took place.
Maybe I exaggerated a little, Dan....the bearings don't actually fall right out of the caps (or the rod itself), and the wear surfaces actually appear to be really nice, but they seem to fit a little loose. For example when a rod bearing is seated in the cap, I can move it around with one finger.
I should probably practice with my el cheapo dial bore gauge and see if the rod big ends are still round, and at least try to inspect it properly....but I already have a new set of rods on the way, so I was going to just use them.
But in the interest of trying to learn something....if there is no "specking" on any of the pistons, is it fair to assume (for now) it did not detonate? I'll post a closeup pic of one of the "good" pistons for visual aid if that helps.
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Re: Oops
[Re: ZIPPY]
#220254
02/11/09 04:51 PM
02/11/09 04:51 PM
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Joined: Oct 2006
Posts: 149 Cleveland Ohio
Discoquik
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Joined: Oct 2006
Posts: 149
Cleveland Ohio
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Very common on New Hemis. Wiseco offers a number of new Hemi Parts that eliminates this very common problem on these engines. The topland is moved way up on the OE piston for emissions purposes. Not good for boosted applications. Our parts come with a GFX ring pack that has a 1.2 Gas Nitrided Top and Napier second. Skirts are coated too. vellinger@wiseco.com
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Re: Oops
[Re: ZIPPY]
#220259
02/12/09 05:23 PM
02/12/09 05:23 PM
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Anonymous
Unregistered
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Anonymous
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Ouch!
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Re: Oops
[Re: ZIPPY]
#220267
02/12/09 11:33 PM
02/12/09 11:33 PM
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Joined: Jan 2003
Posts: 6,591 Canton, Ohio
Sport440
master
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master
Joined: Jan 2003
Posts: 6,591
Canton, Ohio
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Quote:
Same piston. I can tell she was burning a little oil, but that's about all I see.
Zippy, while this picture might not be the picture perfect example of detonation specking, it is good enough to show it IMO. The piston is also heavily oil carbonized to show oil leakage into the combustion chamber.
Witch by itself is a promoter of detonation. The Specking associated with detonation can be best described as a break in a uniform coating of carbon on the pistons surface.
The specks will be silver pinsize potholes to the pistons surface through the carbonized covered sufaced. Looking like silver Specks, Witch your piston displays IMO from the pics as best as I can see.
But in a cleaner burning engine the specks will be more dramatically distinguished compared to yours.
I think you were lucky, you didnt take out the whole motor. Just some pistons, and well, some head stuff. And like stated those ring lands are pretty thin. mike
EDIT, I see you stated it was broke when you got it. And you are just doing the autopsy,
Last edited by Sport440; 02/13/09 12:46 AM.
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Re: Oops
[Re: Sport440]
#220268
02/13/09 07:56 AM
02/13/09 07:56 AM
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Joined: Jan 2003
Posts: 18,025 S.E. Michigan
ZIPPY
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I Live Here
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OP
I Live Here
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Posts: 18,025
S.E. Michigan
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Thanks, sounds like a little bit of everything killed it then. It lived 10,000 miles with the blower and from the sound of the posts here, it was lucky to have run that long.
The car that had this motor in it got a new factory longblock and had the timing kicked back, so I guess it won't be long before we find out if it's going to happen again. From what folks are saying here, it's probably a matter of time...
In the past I've pulled down domed piston/small cam 383s that were run on pump gas, and I could see tiny flecks of material were taken out of the piston....but they were cleaner burning as you said and didn't show signs of oil.
From your description, light detonation on an oil burner will take little pieces of the oil/carbon gunk off the piston before any aluminum gets taken out? I didn't know that. Always good to learn a little something, thanks!
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