I think upto 09 has keystone and square for 2010 and newer. but a shop can put anything in. keystone upside down is an interesting guess. I would love to hear the shops response if that was the case
Modern rings seal up quickly but the Diesel rings do need to be loaded to seat properly. Dyno operators tell me blow by is gone by the end of the first dyno pull normally but a Dyno pull puts 100% hard load on the engine and takes it from just above idle to max RPM at full throttle and full boost. Most would never drive their brand new engine that hard. Cummins says to run the Diesel at 100% max load using 70% throttle as much as you can for the first 150-200 miles to break in new rings. Your shop telling you 10-15K break in, tells me the shop hopes you get used to it and let them off the hook or 12 mos goes by and they say you are out of warranty. Sorry but the engine should be sealed up. Would you accept this type break in on the truck brand new? I would say NO, no one would accept that type blow by on a new truck so don't accept it on your new engine in a used truck.
Keystone rings are the same top and bottom so they can be flipped. the Square or rectangular type standard rings will have a bevel on the inside back of the ring. Top rings that bevel goes up. Second rings that bevel goes down. The bevel is there to help the cylinder pressure get behind the piston ring and press it out adding pressure on the sealing surface to the cylinder wall. When you roll to full throttle the amount of ring pressure on the cylinder goes up a lot as combustion gets behind that ring and presses it out, this helps seal the cylinder giving you more power and less blow by.
The second ring bevel faces down to do the opposite. On the down stroke any pressure in the pan helps push out on the second ring which is your oil scraper ring, extra pressure helps the second ring do its job of wiping excess oil off the bore.
The third ring is the oil ring but in function it is helped by the second ring. Top ring seals your cylinder.
Keystone rings are the same top and bottom so they can be flipped. the Square or rectangular type standard rings will have a bevel on the inside back of the ring. Top rings that bevel goes up. Second rings that bevel goes down. The bevel is there to help the cylinder pressure get behind the piston ring and press it out adding pressure on the sealing surface to the cylinder wall. When you roll to full throttle the amount of ring pressure on the cylinder goes up a lot as combustion gets behind that ring and presses it out, this helps seal the cylinder giving you more power and less blow by.
The second ring bevel faces down to do the opposite. On the down stroke any pressure in the pan helps push out on the second ring which is your oil scraper ring, extra pressure helps the second ring do its job of wiping excess oil off the bore.
The third ring is the oil ring but in function it is helped by the second ring. Top ring seals your cylinder.
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My forged piston motor that was setup on the looser side wasn't anywhere near as bad as that video as well.
I am on the same page as you, something isn't right inside and it needs to come apart.
I'm not ruling out blow-by, but I am thinking there is a bad seal in the turbo or maybe a valve seal. The smoke will NOT increase appreciably from blow-by if you put your finger over the vent.
Where else can excess crankcase pressure come from? Is there any way that boost can move through the turbo into the oil drain tube?
I also thought of valve seals, but they would all have to be practically missing to allow that much drive pressure into the crankcase.
what hes saying is the smoke you get at the exhaust is not a direct cause of too much blow by. hes saying the pressure inside the crank case must be pushing oil out of the turbo or elsewhere to cause it.
Valve seals are on the wrong side of your compression to cause this issue. Rule them out.
Blow by is pressure in the block below the piston rings. Every time the piston fires you will have some pressure blow by the rings. In your case you have lots of pressure blowing by the rings. Remove your oil cap at the filler. Do the same PCV hose block like you did in your video. The pressure should now be leaking out the oil filler cap.
Blow by is pressure in the block below the piston rings. Every time the piston fires you will have some pressure blow by the rings. In your case you have lots of pressure blowing by the rings. Remove your oil cap at the filler. Do the same PCV hose block like you did in your video. The pressure should now be leaking out the oil filler cap.
I'd be going back to that shop and demand them to tear it back down and find the issue. No way in hell I'd pay for a built motor with that low of compression and excessive blow-by. Do it before they say it's past warranty. Everyday you wait is a day closer to them being able to wash their hand of their mistake.
Wrong, the top of the head and the crankcase are connected partner. Both pressurize together.
Finally got the engine builder to call me.
This is all the specs he told me.
.016-.018 1st ring
.022 -.024 2nd ring
.0025 piston to wall .5" from the bottom of the skirt.
Hone 45° 525 grit
He said they did not file the rings at all, they were correct out of the box. So I'm assuming they checked them.
One interesting thing he said, is that they've had issues with a number of engine a year or two ago, with the rings not seating well.
This is all the specs he told me.
.016-.018 1st ring
.022 -.024 2nd ring
.0025 piston to wall .5" from the bottom of the skirt.
Hone 45° 525 grit
He said they did not file the rings at all, they were correct out of the box. So I'm assuming they checked them.
One interesting thing he said, is that they've had issues with a number of engine a year or two ago, with the rings not seating well.
I had my pvc reroute fill with ice and snow one winter and it caused oil to push out the exhaust, but never smoked. I never even knew there was an issue until my low oil light came on lol
That's an indication of a poor ring package OR (and I believe to be more of the culprit) poor quality machine work/assembly. Did they provide a resolution as to what they did to get them to seal on those other engines?
Blow By is created when combustion blows past the piston rings. When the combustion happens both intake and exhaust valves are CLOSED so blowby is not part of valve stem seal failure.
Leaking valve stem seals can certainly use a ton of oil. One drop of oil leaked per combustion will make an engine use 1 quart of oil per 400 miles driven, at least that is what Sealed Power Engineering used to preach. Leaking valve stem seals normally smoke terrible on first start up and then within 25 seconds that blue oil smoke is gone. It will still be burning extra oil but you won’t see it after start up.
He has something else going on. Compression on all 8 cylinders is to low, blow by is high. They are connected and the problem is inside the engine. Cylinder wall finish or piston ring fit would be #1 and #2 place to look.
Did he mention if the engine is using Oil? I do not remember this being an issue.
Reading the specs listed for his assembly notes it all looks good on paper.
Cylinder finish is an art, one operator can give you a proper finish and you use zero oil between changes. Another operator on the same machine doing the same job can leave you with low compression and a oil burner. Some of the more modern honing machines are more computerized and take a lot of operator control away but if the shop Does not change the honing oil often enough we would see problems with piston rings pop up.
I have not worked in that trade since 2018 and I am sure there are better honing machines available but most shops I have been in are still using machines that were first sold in the 80’s and 90’s And the operator of the machine makes it good or bad.
Diamond stones for the hones first started being very popular back in the early 2000 years and at first oil control was a huge issue for shops that switched to the diamond hones. There was a big learning curve but even the OEM engine builders switched to Diamond honing as years went by. They were just much less expensive because they lasted so much longer.
The OEM standard for Oil consumption was moved to 20,000 miles per quart of oil considered acceptable. This was pushed by the EPA. To reach that the OEM’s had to focus on the Ring Package and the cylinder wall finish and Valve stem seals. They all got much better and for the most part last an incredibly long time.
On the larger Diesel engines the cylinder is replaced at every overhaul, they use removable liners If the Cylinder liners are made properly you get a drop in factory cylinder finish and eliminate many potential issues. Some of the liners from overseas were not honed properly and gave the owners fits.
We used to take Fax Film tests off problem cylinders and ship them in to Engineering to evaluate. They could look at the Fax Film which is clear plastic you melt into the cylinder wall and then remove it for testing. Under a microscope they could look at the cross hatch, tear outs, which are micro tears in the metal finish caused by the bore and hone procedure and with this they would tell us how much oil the engine would be burning and what needed to be fixed at the shop to fix the issue. Many times that was new oil in the Hone, change of the angle of cross hatch or more pressure on the stones so they worked properly. Sometimes the hone would have been fine if they took out a little more material but they moved to another cylinder before the hone was complete. If you look at any honing manual the blow up pictures you see showing proper cross hatch and cylinder finish are all done with fax film technology.
The only way I know of Combustion getting into the oil pan is past the piston rings which goes back to, Cylinder Finish, Piston Fit or Piston Ring issue. Hope this helps.
Mark
Leaking valve stem seals can certainly use a ton of oil. One drop of oil leaked per combustion will make an engine use 1 quart of oil per 400 miles driven, at least that is what Sealed Power Engineering used to preach. Leaking valve stem seals normally smoke terrible on first start up and then within 25 seconds that blue oil smoke is gone. It will still be burning extra oil but you won’t see it after start up.
He has something else going on. Compression on all 8 cylinders is to low, blow by is high. They are connected and the problem is inside the engine. Cylinder wall finish or piston ring fit would be #1 and #2 place to look.
Did he mention if the engine is using Oil? I do not remember this being an issue.
Reading the specs listed for his assembly notes it all looks good on paper.
Cylinder finish is an art, one operator can give you a proper finish and you use zero oil between changes. Another operator on the same machine doing the same job can leave you with low compression and a oil burner. Some of the more modern honing machines are more computerized and take a lot of operator control away but if the shop Does not change the honing oil often enough we would see problems with piston rings pop up.
I have not worked in that trade since 2018 and I am sure there are better honing machines available but most shops I have been in are still using machines that were first sold in the 80’s and 90’s And the operator of the machine makes it good or bad.
Diamond stones for the hones first started being very popular back in the early 2000 years and at first oil control was a huge issue for shops that switched to the diamond hones. There was a big learning curve but even the OEM engine builders switched to Diamond honing as years went by. They were just much less expensive because they lasted so much longer.
The OEM standard for Oil consumption was moved to 20,000 miles per quart of oil considered acceptable. This was pushed by the EPA. To reach that the OEM’s had to focus on the Ring Package and the cylinder wall finish and Valve stem seals. They all got much better and for the most part last an incredibly long time.
On the larger Diesel engines the cylinder is replaced at every overhaul, they use removable liners If the Cylinder liners are made properly you get a drop in factory cylinder finish and eliminate many potential issues. Some of the liners from overseas were not honed properly and gave the owners fits.
We used to take Fax Film tests off problem cylinders and ship them in to Engineering to evaluate. They could look at the Fax Film which is clear plastic you melt into the cylinder wall and then remove it for testing. Under a microscope they could look at the cross hatch, tear outs, which are micro tears in the metal finish caused by the bore and hone procedure and with this they would tell us how much oil the engine would be burning and what needed to be fixed at the shop to fix the issue. Many times that was new oil in the Hone, change of the angle of cross hatch or more pressure on the stones so they worked properly. Sometimes the hone would have been fine if they took out a little more material but they moved to another cylinder before the hone was complete. If you look at any honing manual the blow up pictures you see showing proper cross hatch and cylinder finish are all done with fax film technology.
The only way I know of Combustion getting into the oil pan is past the piston rings which goes back to, Cylinder Finish, Piston Fit or Piston Ring issue. Hope this helps.
Mark
His only recommendation was to switch to Driven's DBR oil. Apparently that helped on his other engines.
Kinda. He says there rings were too hard for awhile when pistons were so hard to find, which is when I bought mine. But he thinks different oil will help over time.
But I agree with this. With what I've learned recently, oil is kinda unimportant, at least for initial performance.
I plan to take my truck to their shop sometime next week and let them see it, and ask what they'd like to do.
Right now I'm thinking I'll tear it down and take pictures all the way, measuring everything, etc.
Just an FYI, these is the exact piston and ring set I bought. https://www.xtremediesel.com/mahle-motorsports-cast-duramax-performance-pistons?variant_id=112366
If it doesn't show up, .020" over, 4.075".
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