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Re: Oops [Re: ZIPPY] #220252
02/11/09 10:56 AM
02/11/09 10:56 AM
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Europa, Estonia
Georg Offline
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lucky one
check this out - http://usaraud.ee/?id=15_47_48_72&ll=3


Outlaw Plymouth Valiant R5/P7 Powered by Liuzzo Racing COMP Performance Group dealer in Baltic Premium Performance
Re: Oops #220253
02/11/09 03:40 PM
02/11/09 03:40 PM
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S.E. Michigan
ZIPPY Offline OP
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Quote:

Quote:

Quote:

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.

Re: Oops [Re: ZIPPY] #220254
02/11/09 04:51 PM
02/11/09 04:51 PM
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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

Re: Oops [Re: ZIPPY] #220255
02/11/09 10:04 PM
02/11/09 10:04 PM
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Posts: 6,591
Canton, Ohio
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Sport440 Offline
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It may be fair to say that if you see no specking that there may of been no detonation. But if all the combustion surfaces were really clean and fresh its possible that you may see no evidence of detonation specking.


It seems from alot of what was posted is that those stock Hemi pistons have a very thin ring land at the top. And ring land breakage is a common problem with foced induction even at mild levels.

As Dram/Dan stated hammered bearings are also a sign of detonation. But like you said you may of unintentionally exaggerated that.

Detonation because it happens at the piston will sometimes beat up the piston at the wristpins also if it doesnt break the lands or piston face first. But it will and can carry its force all the way to bearings too.

Im not sure you have a Det problem, I think its the OEM pistons and boost. But I wouldent rule out the det completly just yet.

I look forward to the pics of the undamaged pistons. mike

Re: Oops [Re: Sport440] #220256
02/12/09 11:20 AM
02/12/09 11:20 AM
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S.E. Michigan
ZIPPY Offline OP
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Thanks Mike. I will take some when I get a chance.

They definitely aren't clean, there's carbon and a little oil visible (which I also have heard is common w/new Hemis). I will take a couple shot of one before and after cleaning.

Re: Oops [Re: ZIPPY] #220257
02/12/09 04:22 PM
02/12/09 04:22 PM
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MN
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Quote:

Thanks Mike. I will take some when I get a chance.

They definitely aren't clean, there's carbon and a little oil visible (which I also have heard is common w/new Hemis). I will take a couple shot of one before and after cleaning.




Do you plan on putting the blower back on after the rebuild?


Jerry Williams.
Re: Oops [Re: hemidup] #220258
02/12/09 05:21 PM
02/12/09 05:21 PM
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S.E. Michigan
ZIPPY Offline OP
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No more blower for this poor thing.
It's been through enough.

Re: Oops [Re: ZIPPY] #220259
02/12/09 05:23 PM
02/12/09 05:23 PM

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Ouch!

Re: Oops [Re: ZIPPY] #220260
02/12/09 06:43 PM
02/12/09 06:43 PM
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MN
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Quote:

No more blower for this poor thing.
It's been through enough.




Thats good to hear since there isn't any true tuning for these new Hemi's just yet. The LX cars have a better handle on the tuning, but the trucks are a different story.


Jerry Williams.
Re: Oops [Re: hemidup] #220261
02/12/09 09:23 PM
02/12/09 09:23 PM
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S.E. Michigan
ZIPPY Offline OP
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Yeah, tuning any of the modern stuff can be a pain.

When I get this one rebuilt I'm thinking about putting a carburetor on it, and firing it with the MSD multi-coil box so I can tune it myself. Not sure what it's going into yet but am kicking around some ideas.

Re: Oops [Re: ZIPPY] #220262
02/12/09 09:38 PM
02/12/09 09:38 PM
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S.E. Michigan
ZIPPY Offline OP
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Here are some more shots.

Good piston before cleanup. As folks said, the top ring is indeed very close to the top of the piston.

5021192-5.7piston3.jpg (56 downloads)
Re: Oops [Re: ZIPPY] #220263
02/12/09 09:39 PM
02/12/09 09:39 PM
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S.E. Michigan
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Same piston. I can tell she was burning a little oil, but that's about all I see.

5021194-5.7piston4.jpg (97 downloads)
Re: Oops [Re: ZIPPY] #220264
02/12/09 09:41 PM
02/12/09 09:41 PM
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ZIPPY Offline OP
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Same one, after 5 minutes with carb cleaner and a rag. It has some lint on it from the rag...

Still don't really see anything terribly wrong.

5021201-5.7piston5.jpg (51 downloads)
Re: Oops [Re: ZIPPY] #220265
02/12/09 09:43 PM
02/12/09 09:43 PM
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S.E. Michigan
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Straight on shot, same one

5021208-5.7piston6.jpg (63 downloads)
Re: Oops [Re: ZIPPY] #220266
02/12/09 09:44 PM
02/12/09 09:44 PM
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ZIPPY Offline OP
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All the rod bearings look like this one, almost good enough to reuse.

Should I bother checking a ring gap or two, or is it more of a piston strength/top ring land design issue? After a second look, I see what guys are talking about when they say the top ring land is very thin.

I've never broken anything this bad before...it was broke when I got it, and I was hoping to learn something from the autopsy before feeding the dumpster.


5021210-5.7rod1.jpg (40 downloads)
Re: Oops [Re: ZIPPY] #220267
02/12/09 11:33 PM
02/12/09 11:33 PM
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Canton, Ohio
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Sport440 Offline
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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.
Re: Oops [Re: Sport440] #220268
02/13/09 07:56 AM
02/13/09 07:56 AM
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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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