Piston rings not seating

[715Hunter]

Is the backer spring installed on the bottom ring?

You can see it here. Everything looks good in that regard.

Here's the kicker. I pulled a different piston this morning to verify my suspicions. The second ring has the bevel facing up, but the side marked 'top' is on top. This appears to be Mahle's incorrect marking, or some ring tech I don't understand.

 

[Chevy1925]

in the circled area, is there a concave notch at that edge leaving a sharp scraping edge where it would contact the cylinder wall? It would look like the picture i posted earlier, on the outer part of the ring? picture makes it look like there is one and thats what i was seeing in your original picture.

 

[715Hunter]

View attachment 112429

in the circled area, is there a concave notch at that edge leaving a sharp scraping edge where it would contact the cylinder wall? It would look like the picture i posted earlier, on the outer part of the ring? picture makes it look like there is one and thats what i was seeing in your original picture.

I am already on the road for the week so I can't verify it. I think I can get someone else to though.

Here's a zoomed in version.

 

[Chevy1925]

it really looks like there is a groove which means:

1. the engine assembler should have known better and questioned the "up" marking when the bevel and scraper were on the wrong side. my money says they do the finger pointing game if you bring this up to them. make damn sure they install them the other way if the new rings are marked incorrectly.
2. Mahle stamped the rings wrong and you will get nowhere with them. ive dealt with them in the past on incorrect product details and part numbers only to be left in the wind with "well this is the first ive heard of it". i have a post on here about it. Not long after my dealings with them, all the part numbers for rings changed.... hmmm.

plus side, we found the issue and a new set of rings with the second ring installed correctly will fix the problem.

 

[715Hunter]

U

it really looks like there is a groove which means:

1. the engine assembler should have known better and questioned the "up" marking when the bevel and scraper were on the wrong side. my money says they do the finger pointing game if you bring this up to them. make damn sure they install them the other way if the new rings are marked incorrectly.
2. Mahle stamped the rings wrong and you will get nowhere with them. ive dealt with them in the past on incorrect product details and part numbers only to be left in the wind with "well this is the first ive heard of it". i have a post on here about it. Not long after my dealings with them, all the part numbers for rings changed.... hmmm.

plus side, we found the issue and a new set of rings with the second ring installed correctly will fix the problem.

You pretty much summed it up. I'm sending an email to Joe Maylish at Mahle. He's the one I talked to about the issue originally, and he asked for a follow-up. I'm doubtful that it gets anywhere.

And yes, I'm glad it's a clear solution. The part that sucks is 4 months of down-time to work on it, $500 in gaskets and fluids, not to mention the plain frustration. Oh well.

 

[Chevy1925]

U

You pretty much summed it up. I'm sending an email to Joe Maylish at Mahle. He's the one I talked to about the issue originally, and he asked for a follow-up. I'm doubtful that it gets anywhere.

And yes, I'm glad it's a clear solution. The part that sucks is 4 months of down-time to work on it, $500 in gaskets and fluids, not to mention the plain frustration. Oh well.

if you do confirm the lip is there, let us know because ill make a sticky post letting people know to watch out for this.

 

[PureHybrid]

Hard to tell from your pictures if there is a slight bevel on the OD bottom side, little fuzzy. Almost looks like there is a bevel on the ID as well (top side) but I still can't see 100% from the shadow.

What I find interesting is the instructions James posted, Mahle states the "top" marking superscedes any bevel or notch on the ID

 

[Chevy1925]

Hard to tell from your pictures if there is a slight bevel on the OD bottom side, little fuzzy. Almost looks like there is a bevel on the ID as well (top side) but I still can't see 100% from the shadow.

What I find interesting is the instructions James posted, Mahle states the "top" marking superscedes any bevel or notch on the ID

Right? its like they knew this would happen and probably why he will get no where.

 

[715Hunter]

Mahle's response to these same pictures:

From the engineers:


The skirt wear does look high for little run time.


"The cross hatch looks really rough. They should not be able to catch your fingernail on the cross hatch.



The 2nd ring is correct. For DMAX rings, the bevel goes up.



I hope this helps.



Kind regards,

Joseph Maylish"

Hard to tell from your pictures if there is a slight bevel on the OD bottom side, little fuzzy. Almost looks like there is a bevel on the ID as well (top side) but I still can't see 100% from the shadow.

What I find interesting is the instructions James posted, Mahle states the "top" marking superscedes any bevel or notch on the ID

The ID bevel is indeed up.

 

[PureHybrid]

Either Mahle knows something we don't, or they're wrong

 

[Chevy1925]

Mahle's response to these same pictures:

From the engineers:


The skirt wear does look high for little run time.


"The cross hatch looks really rough. They should not be able to catch your fingernail on the cross hatch.



The 2nd ring is correct. For DMAX rings, the bevel goes up.



I hope this helps.



Kind regards,

Joseph Maylish"


The ID bevel is indeed up.

Until you can verify about that outer edge I was talking about, i take that with a grain of salt

 

[danzick]

I'm wondering about the hone job? after reading what Mahle said about it, I went back and looked at pictures of mine when I got it back and it doesnt look near that rough. Maybe the pictures are deceiving?

 

[715Hunter]

It should be the correct stone. Mahle reccomends a pretty rough one for their stainless rings.

I'm wondering about the hone job? after reading what Mahle said about it, I went back and looked at pictures of mine when I got it back and it doesnt look near that rough. Maybe the pictures are deceiving

 

[LBZ]

Finally had a couple days to pull this thing apart on get a good look at it. Pictures below. There's no wall glazing, which surprises me. But tons of half-burned oil above the first ring and a bit between the first and second rings, as well as some weird deposits on top. I pulled one cylinder to check gap before sending it back to the shop. 1st ring was .016" and second is .022".

That piston looks like it was in there for 100 000 miles with those wear marks on the skirt and above the top ring. I’d be asking for ALL the measurements from that shop of Piston to wall, ring gap and bearing clearances too! Something looks off for that low mileage.

 

[PureHybrid]

It should be the correct stone. Mahle reccomends a pretty rough one for their stainless rings.

What grit did they say, and are they wanting a fine grit to finish in a plateau?

 

[Bdsankey]

That piston looks like it was in there for 100 000 miles with those wear marks on the skirt and above the top ring. I’d be asking for ALL the measurements from that shop of Piston to wall, ring gap and bearing clearances too! Something looks off for that low mileage.

Now that you say it, that is a ton of wear on the skirt coating.

 

[danzick]

That piston looks like it was in there for 100 000 miles with those wear marks on the skirt and above the top ring. I’d be asking for ALL the measurements from that shop of Piston to wall, ring gap and bearing clearances too! Something looks off for that low mileage.

what would cause that? large PTW clearance and the piston rocking in the bore?

 

[LBZ]

Possibly PTW and I have seen it look like that when someone puts the piston in backwards.

 

[turbovan]

Pics are deceiving but that cross hatch looks like it wasn't even ran.

Another shop had the same issue, mega blowby after the rebuild, turned out they put the front seal or rear main in backwards. Can't remember which one. It was literally puke smoke, oil out of the crank seals and pcv. Would build pressure on a gauge. Put the seals in properly, fixed.

 

[715Hunter]

Long-awaited update.

Back in February I had a great conversation with someone from Total Seal, (I forget his name) and he basically told me the problem was with the hone, just like everyone else has.
On his recommendation I took the short block to Baldwin Racing Engines in Friedheim, MO. Almost a 4 hr drive for me. He put a profilometer on it, and it's simply way, way too rough. I'll post a pic of the reading below. It appears to have started correctly, but never had the finish hone needed to knock the peaks down. This is why the extreme skirt wear, brand-new-looking cylinder walls, and of course the blowby.
It's now been sitting at his shop about a month, where it's getting done right, as well as new gapless rings from Total Seal. He's giving me a pretty good price on the work needed, and ironically, when combined with the last shop's bill, adds up to what most places quoted me way back. Anyway, it'll be awesome to have it back together soon. I'm swapping the turbo and CP3 for better stuff while it's open as well.