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The machinist that did my work recommended Hylift lifters and the DBR break in oil. I went with a Colt stage 2 cam and she’s running great on Schaeffer’s 15w-40 every 5k.
The oil filter, like every other design, has the ability to bypass when the oil is cold, to prevent the media from blowing out. This is because the weakest lobe goes first, and while some say it's always the last lobes, that's not true.
There can be several manufacturing causes too. Material, grinding speed and pressure, final surface finish. You can also have issues if the oil allows the roller to slip on the surface. There are a vast number of studies looking at lobe failure, not so much lifter roller failure. There is no reason for a research engineer or scientist to look at parts they do not believe are failing. I spent about $150 buying SAE papers on the subject. Read what I am allowed to post.
Look at my posts where I calculated the Hertzian contact stress. The 6.0L has very high compression under the roller. I won't be using any higher-rated valve springs. However, since it's a surface fatigue issue, the concern is based on the product's expected life. You can run high HP engines for short periods and be happy.
The crankcase is a mass oil throwing event; there's no curtain. More so with the Powerstroke due to the cooling jets.
Powerstroke engines make it to 300k, 500k, 1,000k... what is the trend is people who have oil cooler blockage. Unless you have a Ph.D. in material science or a Master's from MIT (my old bosses) and the research assets of an OE company, you're not going to have a hard answer.
Cool info thanks. My deltas never exceeded 18 degrees when my EGR cooler was taking a dump. Which is only 3 degrees of the generally accepted variance. If the oil temp is that sensitive then the 15 degree variance is prolly too high to go by. So what's a guy to do to above and beyond to lower oil temps? Add a secondary air-to-oil oil cooler somewhere? I don't race my truck, or pull heavy loads, she is mainly a commuter and grocery get'er or weekend trip to the coast truck. B.
Eighteen degrees when doing the differential test or during the hardest work the engine has ever seen? I know, grocery getter.
As Mark has noted repeatedly, the temperature measured across the oil cooler is not necessarily the hottest oil in the engine. So if you are reusing that block, check the piston jets for anything that might be in them clogging the nozzles, especially those with the poorer cylinders. Piston cooling oil rains down on the camshaft lobes, and that's hotter than what is out of the cooler. But an injector that is pushing more fuel will also cause a hotter piston and therefore hotter oil. An injector issue at 6?
There is more to it than just the oil temp; as I said, the weakest lobe will go. I'm not a fan of the hardened layer thickness the OE cam manufacturer uses. Neither is Geoff Bardal of Colt cams, which said the words I wanted to hear when hunting for whose cam to buy. But that's just me. I sent my OE cam back to Tasca when I found inclusions in the lobe surface. To me, that is an indication of the QC done. From my history of working for a company that supplies the assembly line, service parts, and the Aftermarket, the best quality parts go to the assembly line. Things go downhill from there, and the aftermarket side of an OEM will never invest in the quality aspect of the manufacture. They can't without being priced out of business.
Continuing on .....
You can see the same characteristics on the next two pages in Dexter's cam lobes.
Read the dialog about debris distribution.
The Hertzian contract stress is projected through the hardened layer into the softer material. Both have the same load-deformation, but the transitional area has crystalline inclusions, which can be the fault. The deeper you go, the stress is reduced as the force is spread out. Therefore, you want the transition layer to be deeper into the material, and you want the grinding of the lobe not to introduce any abnormalities.
I also polished my Colt cam, but that's another story. Too smooth and the surfaces can slide; too rough and stress risers. Let you know if the motor ever gets to 300k,
The contact stress on the 6.0 cam is much higher than the 7.3 cam by 31% to 35%, and the depth of the stress is deeper by 20% (same suppliers of cam and lifters), and the 7.3 has a lower failure rate than the 6.0.
Another example of cam lobe failure.
When the wear-resistant hard shell of the M&M is popped off, you are left with soft chocolate.
Awesome information there Jack. It makes perfect sense. I DID have an injector failure about 20 months prior to my current string of issues with this engine. AND, it WAS on cylinder #6 in fact. After it was replaced I experienced low performance on that cylinder for a few weeks as the rings resealed. Then she ran great until September'ish of last year. When she again started running rough with a cylinder miss. That may explain why the rings eventually failed on that cylinder AND the exhaust lobe on the cam got wiped out.
I really need to pull that piston out and see what it looks like. B.
Ok, I pulled the "damaged" lifter apart from cylinder 6. Considerable amount of damage to the roller axle. You can also see where the roller was hitting the under side of the lifter. And the roller is obviously no longer round. I don't see any discoloration or caked on oil residue indicating excessively over heated oil from an over fueling condition caused by a bad injector. I'm kind of wondering it was just a bad lifter? Take a look. B.
Ok, here is the cylinder, piston and rings. The top ring is beveled? I have never seen that before. The side are not parallel. The end gape on the top ring was .013". The second ring has parallel sides. And the end gape was .054". Excessive I would think. And the oil control ring is um..... unique? I have not seen that design before. And the coils are not consistently would. Is that normal? Take a look. B
In my 2004 LandRover Defender TD5 I have such a centrifugal filter as a secondary filter, it works very well. It would be interesting to know if 6.0 with retrofitted micro filter have less lifter / cam problems.
I honestly don't believe that filtering the oil is the answer here. And there is not enough cam and lifter failure to go off with our hair on fire. It happens, but not to the frequency of head gasket failures.
It's hard to say without extensive research what the initial failure is. You have to catch multiple failures and see the trend. For example, did a needle start the process and hurt the lobe, or was the rough lobe the cause of the needle failure? Or did the surface of the hardened axle fail first? From my viewpoint, you will not see carbonized oil on the surfaces of failed parts; it's not that kind of failure. I believe this is why there is so much research being done for the last decades about cam failures.
From Chevron's paper that I posted here already, highlighted for my video, not for this discussion. However, this 2000 paper is oil-based. All the highlights from my posting are related to the video. Since then, we've gone through many oil modifications, and those of us who have done oil analysis has low soot %, nothing like 5%. Mark has gone through a lot of gymnastics about the changes in oil over the years.
The valvetrain is highly loaded with a 6.0. It's why I spent so much time publishing work and still have more to finish.
When I did the Hertzian contact pressure calculations for the lifter needle bearings, it wasn't as high as what's achieved on the cam lobe. But the rotational speed is much higher. When I went through my needles, I did find some fractures and some debris scoring. I found the same from Pete's (87crewdually) when I took his front, easy access lifters apart, although not as bad as mine. As yet, I haven't had time to do Dexter's lifters.
So what type of oil additive should I use when breaking in a new cam and lifter? Is this the normal profile of the top ring? I have never seen a top ring with a taper to it. B.
I haven't had the pistons out of my one and only Powerstroke, so I can't comment on the rings. However, Mac (Smackdaddy) has. But I've encountered tapered rings over my lifetime.
Is that your worst-case cylinder bore because that does not show any deep scoring, just light scuffing. Is there a wear groove at the top (ignoring carbon buildup) of the cylinder where the ring stops? And your rings gaps are within spec. Do you feel any play in the piston rod bearings?
Let me add the International Service manual as it's better than the Ford manual. You might want to peruse page 215.
Considering the trouble you have finding a local machine shop, have you considered the engine may just need a complete cleaning and a ball hone refresh? I don't remember how many miles you have on it. It's always hard to tell about deep scratches without being there.
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