The Machinist

The internet delivers again.

I believe this picture from an eBay auction shows a block off plug for an oil gallery.

It would not be difficult to test oil pressure at this plug, or route external oil feed to this plug on both heads.

VektorPerforman

DLC is a generalized term. The higher end plasma deposited coatings do not wear off like paint as they are made specifically for wear applications. I should have been more specific. I've spec'd many more coating types than I can name or remember since the mid-90s; zinc, zinc/chrome, Tin, TiCN, TiAlN, and even Armaloy. Armaloy is basically a 'proprietary' coating that's been a round for a long long while. Some of the legacy (i.e; old) stuff I've worked on has had it, and we continued to use it since it did the job. There are several other 'proprietary' chrome coatings that are similar in premise and promise. I've never had issues with any of the chrome wear spec coatings I've used, but it wouldn't be my preference for this application. I'd lean towards a higher end machine tool coating as they have more similarities in operation and environmental conditions experienced with a camshaft. Although, as I've said before, the coating is going to prolong metal-on-metal wear, but if there's good lubrication, there never should be metal on metal.

A very quick search for a technical paper showing camshaft wear and coatings concurs... LINK HERE.

Thinking more on this, you'll also find surface finish can also improve minimal lubrication conditions. Again, I've not seen these cams in person or under magnification, maybe they are awesome, but I've never seen cams that didn't have an improved finish after applying a micro or super finishing process. Again, I think the bigger fish to fry here is proper lubrication.

Thanks for sharing the pic of the head. I'll see if I can dig up a factory lubrication circuit diagram to see what's last in line. Does anyone know if there's an actual oil pressure sensor (and where it is) on these engines or just a low pressure switch? If there is a sensor I can likely do some logging on the dyno via the OBD2 port. If not, we can still log it, but installing the pressure sensor is obviously more involved.

roadtalontsi

confirmed all adjusters are the same m156 and m159.

The Machinist

Its doubtful that it is anything more than a pressure switch. Oil pressure gauges seem to be a thing of the past. If the oil pressure can be verified at the ports in the head as adequate, there is little to be done other than adding supplemental oil squirters directly to the camshafts under the valve covers. It’s been covered here before but the consensus is that the wear is made worse by a dry start condition which can be reduced with an Accusump.

Oil squirters..... Does anyone have a set of aluminum valve covers for sale? I might be needing to weld some nozzles to them.

Have read that DLC paper.


TiM TiAN et.al and DLC are still a Vapor Deposition process regardless of what temperature, pressure, or voltage it is performed at (the plasma part).

Armaloy TDC has a CoF .09 Their XDC has an even lower CoF but is 30% more expensive.
DLC has a CoF of .13

The “proprietary” part of it has to do with how they apply it, Not what the coating actually is. Normal chrome plating processes result in very uneven accumulation with sharp edges requiring further machining to the profile. The TDC coatings have a uniform thickness of .0001-.0003” which is quite a bit thicker than that of the DLC process, and about 10 times thinner than a typical engineered chrome coating applied via traditional chrome plating process.


I don’t know what the Titanium based coatings have for a CoF and my experience with them is mostly on carbide tooling or compressor blades for certain gas turbine engines. In both cases it is designed for abrasion resistance in those applications with little regard to the sacrificial surface it is operating against. Once it fails, it fails all at once and in a big way.

In the plastics industry they use TiN in certain parts of mixing equipment for corrosion control. We did not use it for wear surfaces like shown above because it is too thin, and too expensive.

If money were no object as some of the more high-end coatings seem to demand, I would simply pay the $8000 for the billet camshafts, and the $2,000 to a certain parts supplier for black series lifters.

I want to send my existing cams and lifters before they wear out to get coated and see how long they last. If I have to pay a little bit of money up front so my parts last longer it is worth it to me.

Chrome has been used in automotive applications on piston rings for decades for its tendency to resist wear and stiction.

Ideals are a luxury most of us don’t want to pay for over and over again, I already bought the damn car. It’s why Audi’s are all worthless after 10 years. No one wants the unpaid repair bills. If there is a well tried and cheap alternative(chrome) to buying camshafts, lifters, adjusters, and a bucket of TTY bolts every 100k miles amid the withering stares of family members thinking “I told you so,” I’m willing to try it.

The Machinist

On the pictures of the mixing rotors I posted, I should clarify that the black material stuck to the rotors is not missing or damaged chrome, but carburized rubber that was burned and stuck to the insides of the mixer. The customer was complaining of poor throughput and we traced the problem to a component downstream causing the rubber to dwell in the mixer for too long and burn.

VektorPerforman

Machinist, you know for sure this accelerated wear is mostly from startup? I as many others are not a big fan of an Accusump as a means for protection from in operation starvation, but as a priming tool they work very well. My personal experience with them for priming is all based on turbo applications as using them to prime a fresh engine is generally a very bad idea. If startup on these engines can benefit from an Accusump prime, that seems to be a cheap alternative to valvetrain.

I will reach out to some of my contacts in the high performance oil industry and see what they recommend. 10 or so years ago I was recommended an oil that was made specifically for 'limited use'; typically high end/high HP cars that spend most of their time in storage. Its characteristics included additives that improved oil adhesion to metal parts over the long-term (reduced hydrophilic properties as well), as it was designed specifically for those applications. If the M156 has similarities at startup to cars that are stored long-term, maybe we could benefit as well?

I'm going off limited experience here and have only a couple Oil Analysis results for this car so far. I'll scour the forum for those that have good historical oil analysis results, and have experienced accelerated cam wear to see what trends to keep an eye out for.

The Machinist

Be careful. Discussing engine oil here is about as useful as discussing politics.

I am skeptical of a Mechanic in a bottle. It is wishful thinking. I have had to eat my words with Ceratec and MoS2 additives before, but they still do not work miracles.

The Accusump method works on other engines that have similar problems with valvetrains that are heavily reliant on hydraulic components. chain driven Audi V8s are notorious. I own two of them.

It will help with preventing collapsed lifters from destroying themselves, and it’ll reduce the rate of wear on the adjusters, which is another topic that I have a solution for up my sleeve.

The dry starts aren’t helping. The truth is that every engine experiences a dry start every day just like this one. The M156 just sucks at it.

Pages back, we all but confirmed that the problem with the cams is related to a **** poor job done with the case hardening process before the finish grind. The grinder went right through the case leaving a soft spot on the tip of the profile. While not on camshafts, I have personally ground right through a case before and it is very obvious when it happens. The sound of the wheel on the steel changes, the color of the sparks change, the wheel spindle load reduces, and the tolerances become a lot more difficult to hit. On a mass produced item like these cams it would have been difficult to notice unless the machinist was standing right there when it happened. More than likely, he was what we call a button pusher. Load the part and press the green button.

That is why they are wearing out.

VektorPerforman

I have a good 10+ years designing oiling products and have always stayed clear of those conversations. Even with the contacts and resources I'm fortunate enough to have doing what I do, I tend to keep my opinions to myself as there are always others that know what's better (even if it's not), lol.

We have a 15 year and hundreds upon hundreds of testing history with Blackstone labs, so I also reached out to them requesting M156 data and they got back to me already. Nothing conclusive unfortunately. The engines generally wear well when the OEM spec oils are used. They did say the 0W oil would improve startup lubrication time, which makes sense as the lower weight has less resistance to flow.

You have hardness sections across the cam profile? If these cams crap out this often I'm sure they can be had for cheap to cut and test. A coarse test would be a rockwell across the faces in 2 directions, and a micrograph cross section would show even more detail in the hardness depth and profile.

One of the most common issues with cams is hardness, as the manufacturers tend to have a one size fits all approach across trim levels. This means more aggressive cams tend to have the least material removed and the best wear rates; contrary to conventional thinking, because more of the case is intact. Anyone have cam specs across all the M156 powered vehicles? That data might be fairly telling. I've never re-case-hardened a camshaft before or have any idea how bad of an idea it may be, lol. My instinct says they would likely twist up pretty good.

The Machinist

I do not have a set of cams in front of me, but have been working with Go Team who does have a set.

He found that the cams did not have a consistent hardness around the profile of the lobes by doing a file scratch test.

I do not have access to an electron microscope for the micrographs. I did in college, but that was then this is now.


Redoing a case would not be a bad idea if it was done by someone who knows what they are doing.

The cam would need to be annealed, the. Heated to quench temperatures, quenched, then tempered down to the hardness you want.

That process is dependent on the chemistry of the steel, which as close as we can come is some form of high carbon forged steel.

As I said earlier, the cams were hardened and done so quite well. But too much material was left on the cams prior to the finish grinding.

The cam grinder blasted right through the case before he got to finish size.

Parts of the cam that are not machined are as hard as a coffin nail.

roadtalontsi

I've definitely found that using 0w40 vs 5w40 or 10w40 has aided in lifters not sticking first hand. Back at the dealership I had a come back from another tech who did a service. Ever since on cold start the lifters would stick and knock until warm. I drained the oil (knowing it wasn't correct) from the generic reel oil (alleged to be 10w30) to 0w40 mobil 1 and poof it was fixed immediately. I know everyone hates on mobil 1 but I'd take regular 5-10k oil changes with it rather than 15-20k intervals with the best oils known to man.

The Machinist

That right there puts some weight on the insufficient oil supply to the head theory.

I have seen an entire cylinder head on a certain DOHC 4cyl GM product fed by a tiny orifice about 1mm across. I drilled that ***** out to 1/8”. That head was silent after that.

VWs are fed by an orifice next to one of the head bolt holes. The oil supply follows up alongside the head bolt and enters a port near the top of the head next to the gallery.

Maybe I need to put together some external feed lines. It certainly would be interesting to know what the actual pressure in the head oil gallery is.

go team

Should help provide a nice transition in/out of phaser lock 😎. Stock adjuster pin on the left. Took this thread off-topic oh well

Cwagon

From watching Tasos's videos he does the pin flip to get the sharp angle back.
He it makes the pin lock better into the plate as the plates wear the groove out of the hole.

go team

That new sharp edge from the flip will grind that soft plate even more. You don’t want pieces of that pin breaking off in your head. It’s like 60 HRC. Failure analysis doesn’t always mean maintaining stock dimensions just for the sake of doing so and having a fresh edge. The wear pattern tells you what needs to be adjusted in this case.

i also believe he flips the pin to help it stay in the plate as it has worn down and turned into a ramp with no lip, the plate that is.

go team

Lots have happened in this and a few more data points to put in.

The DLC coating I chose for the plates because of its chemical strength in molecular bonds (p-orbitals completely filled). As such you will find endmills and various bits and bobs in the machining world coated in DLC for its superior wear resistance and chipping resistance.

Further research on this can see benefits of wear resistant to the 10^3 degree. When two DLC surfaces come in contact with each other the resistance is exponential to 10^6 degree.

Problem: DLC is a lose term and different practices and films of DLC are not necessarily regulated. There are few companies that perform the DLC coating to a satisfactory degree where repeatability and reproducibility is present. I have only dedicated to use such companies. These companies also provide certificates and analysis guarantee to ensure the film is measured therefore assisting in quality control.

Another datapoint is in the medical field where knee replacement hardware that have historically lasted 15 years have now a lifetime expectancy from DLC coating on BOTH hardware surfaces.

In conclusion re: DLC, chipping is an issue for poorly coated parts and it all depends on how the parts are prepped and the DLC film quality that’s used.

Now onto cams:

I have now plans to treat a FULL set of cams in a diffuse heat treatment to encase the cams in a strengthened case of metal to enhance the metals properties. I had to try several times as the cams are induction hardened and depending on where on the camshaft you are testing it will have a different hardness value.

So the treatment does a few things. It actually has shown to enhance the surface finish, thus lowering its CoF, it has a barely noticeable dimension change barely a few microns, it has hardened the lobe to closer to 60+ RC and you can tangibly feel the cam journals spin freer within the head when compared to the stock cams. I coated the whole camshaft journals, threads, EVERYTHING!

Testing on delamination specifically to the threads: I had another project which was aftermarket bolts that are reusable. I torqued the bugger to 190 lbs/ft on the treated camshaft threads. I had no issue with thread deformation when I put several fresh bolts in. I had another test on delamination albeit on the (camshaft adjuster cover) to see if the countersunk bolt recesses would fold or chip away. This was not the case. The thinner edge of the recess deformed from getting whacked a few times but never chipped off. This is a good data point that shows the properties of the patent material remains and a great example of what an impregnated layer means. NO delamination NO chipping. The front adjuster cover however is also very soft.

The benefits: if you had questioned chipping as an issue with DLC, that would definitely be not the case in the case hardened impregnated treatment. If you encounter a low oil supply situation if you have the updated lifters with the coating it will be more resistive to wearing due to the tribological properties it has attained. The core spring-ability of the camshafts are maintained. The camshafts do not deform due to the low heat applied in the treatment. This is NOWHERE near as heavy as any aftermarket billet camshafts out or to be released in the future so parasitic losses from rotational inertia is not a factor.

The negatives: this is by no means a power mod. This is a mod to ensure the top end is bulletproof and will not experience anymore premature wear. Next, one will still need camshafts in mint condition to benefit from the treatment which means purchasing new cams or hoping to hell that your camshafts are in good condition to begin with. If you do this treatment you have to replace your lifters. The reason is with the treatment in effect “sealing” micro-imperfections on the lobe the old lifters that have been engraved with the original camshafts will eat and act as sand paper to the new treated lobes. You would want fresh lifters with fresh surfaces. And lastly you could still find yourself in an oil starved situation as this does not fix poor oiling of the head. So while this is close to a solution, the big target has now become adequate oiling. I know that the coating will improve the outcome of inadequate oiling but to what point? I’m not sure. I am hoping there’s an end to this 🤦‍♂️. Maybe I’ve overthunk it and hopefully what I’ve done is enough. I may readdress the oiling issue after the findings that come out this year with the cams.

Machinist is looking at a solution for supplemental oiling but I that is something I can’t do justice explaining.

Just another bit of addendum from the discussions above. PVD coatings I would happily apply to smaller simple systems like the adjusters. I do not offer the recommendation to apply it on the camshafts for my own fear. But the coating on the BS lifters appear to be DLC. Personally I would much prefer an impregnated diffuse layer on the camshaft knowing it’s springy properties. For anyone interested here is the DLC coating DLC. This is nothing against DLC but more a personal view.

Bank 1 and Bank 2 below. Excuse the dirty threads that is not a final production camshaft.

VektorPerforman

Looking forward to seeing historical wear data and oil analysis results. Enough of us out here are collecting analysis results for every oil change, so there may be clear trends in wear metals that support the hypothesis.

How many engines or test time is this going to have before offered to the general public?

go team

My baseline oil changes are in the UOA thread. I will probably put at least 15,000 on the setup with plenty of oil changes to keep track of what’s happening. If the UOA are clean I would be keen to offer it. If I see trace amounts of anything in UOA that’s outside base it’ll be held back. Driving conditions will be mix of track and road.

The Machinist

I will be continuing on the Armaloy route for my cams, running on OE new non BS lifters. I will keep apprised of my data.

I think what’s sold me on the Armaloy most of all is not only my experience with it in the plastics industry, but also the fact that it is used to coat gear teeth too. That tells me that it takes point load as well as sliding forces which is exactly what camshafts delivers.

I can’t say as I’ll be doing oil analyses as I do not have that kind of self control. I will be tearing my valve covers off periodically to have a look. Reminds me I got to call that dude to see how he’s doing with his build.

I will be continuing to work with Go Team on the oil flow supplement as I implement it on my engine.

E63007

I had removed my Heads when I first got my 2007 E63 due to the idle revving at 1200rpm. It turned out to be the Intake Throttle Body Plenum which was riddled with holes. Then I saw the intake runners coated with carbon buildup, so off with the Heads it was. It turned out there were numerous other issues I've mentioned on other Threads and wont go into detail here, but all is completed now and this thing runs just Great!!

That said, because of those issues, one of which was both Cam Adjusters were Not Only installed on the wrong Cams, but the insides of them were flipped around backwards such that the little Oil Barrel Pin was on the opposing side facing the Cam, instead of the Sensor!! This, of course rendered them being not only ineffective but also resulted in each Adjuster to be pulled away from the Cam because the Cams would not seat properly against that Diamond Washer because of the fact that the inner face of the adjusters were the side that was supposed to seat the Cam Bolt instead!! As such, the end of the Cam was restricted from fully seating due to the diameter of the inner face being too small. So the Cam Bolt itself and the pressure of the the Cam being jammed up against this smaller recessed hole coupled with its being barely precariously supported by drive gear below, was the only thing enabling the Cam to turn as the Diamond washer wasn't even close!! This explains why 8 of 16 Intake Valves were bent. Moreover, as mentioned, this placed each Adjusters Teeth precariously offset with the the Drive Gear below it!! Amazing it didn't self destruct before I took possession!! I never asked the owner/re-builder of Xtreme Heads from which head they were predominantly taken from, but my bet is that all 8 were on the side where those Cam Adjusters were installed *** backwards!!!

I did end up installing the SLS Black Valve Tappets that I understand are coated and therefore more durable than standard. Since I had to rebuild my Cam Adjusters, I did notice they were fairly worn where that Barrel Pin seats. Therefore, I will get in there at some point and rebuild them with E63 Motorsports fine offerings. At which time I would very much like to be able to install new CamShafts to boot! Yeah, I'll have to spring for new Valve Tappets when I do hopefully do this!! I understand Tasos, our M156/157 YouTube Guru from the UAE, is getting close to being able to offer his iteration of M156/157 CamShafts as he points out in one of his more recent videos that the New M156 CamShafts aren't uniform in that some come with properly cut Oil Journals and some don't! Yikes!! The jury is still out with regard to exactly how they will be crafted however.

As such, it would be great to get an update from "The Machinist" with regards to perhaps an even more durable M156 CamShaft product!!!!

swedepat

I´ll tell you why the cams are worn down but you need to be openminded.
It is known that the intake camshafts are seeing more wear than exhaust, this is due to there is no oilbath above the buckets(when static) on the intake camshafts, the exhaust do have it.
This make the startup lubrication far superior on the exhaust compared to intake.

And if noticed different HRC around the lobes can also have its cause in the lubrication error, as the most wear is on the highest point of the lobes(most pressure, less surface area, most friction, heat buildup)
Finally, going above 58-60HRC to deep into material on engineparts is to beg for problems, they get brittle.