Cracks in the bearing cage? Various frequencies created as a result?

Nope.. But this could increase load on the cage and lead to premature failure :-)

Are you seeing a build-up of some kind on the bearings??

Jake,do u believe that regardless of how well the bearing is lubricated (ie DOF) the inevitable is bearing failure eventually regardless off single ,double ect. From what ive read
it would appear that lack off regular oil changes,wrong oil viscosity,driving at slow paces in higher gears,staying at 3000 rpm for extended intervals ect all will contribute to earlier failure but basically at standard bearing in this application is a bad idea and nothing but taking the bearing out off the equasion is the only SOLUTION!!

Based on my direct experience the problem is the application of a ball bearing. The constant that I have mentioned in this thread applies to every IMS Bearing equipped engine from 1997-2008.

Opinions will vary and mine is very biased. Some contend the exact opposite of this.

The attendees of my class just learned of this constant today. Their jaws dropped when I held the bearing in my hand and illustrated just one thing. I could see the "dots connect" pretty quickly, then came the comments.

Tony is going over the IMSR procedure now in class :-)

Jake,
Any idea of the typical run out on the IMS driven gear? I had the failed IMS from my engine measured at 0.015. Quite a bit for a gear, but as it is a chain drive if may be ok. In any event that was a major driver in replacing the damaged shaft with an undamaged one. My thought at the time was if the IMS gear run out was poorly controlled in the design, additional side loads could shorten bearing life in high run out cases even with a deep groove ball bearing.

Good thought that few consider. The acceptable runout is less than 1 thou. for my engines.

Too much runout, and the associated timing chains see accelerated wear as well as the replacement bearing. This is one reason why we highly discourage cutting the race of a failed bearing out of a shaft and resurrecting it, because the heat and trauma associated with bearing failure often creates runout that can lead to shaft separation or future bearing failure.

One supplier of "rebuilt shafts" is selling shafts with another bearing design that have previously failed and have been "repaired". We'll see how that works out for them and the buyers.

Jake, without getting into semantics, surely you must agree that the problem is a combination of the original bearing design/s AND inadequate lubrication. Indeed, even on your own site you highlight the same under the heading IMS Failures Explained:

"Next, while the grease seals may still be intact, the permanent lubricant inside the housing has been dissolved. The compromised grease seal now provides a barrier, preventing the seeped-in engine oil from leaving the chamber, but also preventing enough fresh engine oil to enter that might cool and lubricate the bearing surfaces." Then "as inadequate lubrication, extreme heat and corrosion continure, mechanical deterioration accelerates."

IMS Failures Explained

I can only assume that you continue to believe, based upon your likely unparalleled experience in rebuilding M96 and M97 engines, that these are amongst the stages of IMS failure and that inadequate lubrication is a significant contributing factor.

What can we safely conclude about IMS ball bearings?

1. BALL BEARING IMS BEARINGS CAN WORK:
We know this because the vast majority of M96 and M97 engines do not suffer IMS failure. Many have gone well over 200,000 miles on their original bearings (both double-row and single-row) without suffering a failure. We must keep in mind the numbers released by Porsche and the fact that they are based upon hundreds of thousands of cars produced and up to 17 years of real-world use.

2. SOME SEALED FACTORY IMS BEARING DESIGNS ARE MUCH MORE RELIABLE/DURABLE THAN OTHERS:
- based upon the data obtained from Porsche during the discovery process in the class-action suit, the original dual-row bearings failed at a rate of much less than 1% regardless of mileage, use and maintenance schedules, whereas 8 to 10% of the original single row beaings failed.

3. CERAMIC BALL BEARINGS ARE MORE RELIABLE/DURABLE THAN STEEL BALL BEARINGS OF THE SAME DESIGN:
- As you indicate in reference to your own ceramic IMS bearing retrofit (and as confirmed by testing and years of experience in various applications), properly engineered ceramic ball bearings are more durable/reliable than properly engineered steel ones.

4. ALL BALL BEARINGS NEED ADEQUATE LUBRICATION:
Trite, of cousre, but important. Porsche erroneously chose not to lubricate their IMS ball bearings with oil, but relied upon a seal to keep the bearing packed in grease. As you highlight on your own site, as the seals start to fail on these bearings, sufficient oil is allowed in to wash out the grease, but insufficient to allow adequate lubrication of the bearing by oil. Ultimately, the result is failure of the bearing. Pedro echoes your observations in this thread when he says: "The oil that seeps into the IMS is not replenished and that's why (the bearing) is cooked."

5. THERE ARE TWO WAYS OF IMPROVING THE LUBRICATION TO THE BEARING:

The most simple of these is by removing the outer seal to the original IMS bearing - something which you and many others recommend as a stop-gap measure for those with the later, larger single-row bearing who cannot afford an engine tear-down in order to upgrade the bearing. Indeed, it is also why your (and Pedro's) ceramic retrofit bearings are unsealed. This method eliminates the grease and relies upon splash oil to lubricate the bearing. A question remains, however: is splash oil lubrication adequate in the long run, regardless of how the engine is used? There is insufficient data at this stage to answer that question definitively and, indeed, you recommend replacing your own ceramic bearings every 50,000 miles or 4 years.

The second method of improving the lubrication to the bearing is by DOF (direct oil feed), rather than splash lubrication. This is the method extolled by Pedro. Clearly it will provide much more oil and lubrication to the bearing under all driving/idling conditions than splash lubrication. Using it will undoubtedly eliminate the inadquate lubrication problem that you and others highlight as one of the stages of IMS failure.

Will DOF cause inadequate lubrication elsewhere in the engine? As we all know, oil pressure varies wtih oil viscosity, oil temperature, rpm's and engine wear. The M96 and M97 engines were designed and built to take this variation into account and there is no reason to believe that directing a small amount of oil to this bearing will reduce oil pressure elsewhere to a point of inadequate lubrication ( unless, of course, the engine is already suffering from low oil pressure). Indeed, you include direct oil lubrication to the bearing in your IMS Solution and must have come to the same conclusion.

Will DOF cause increased aeration and foaming in the oil that modern oils are incapable of coping with? Comparing the oil on the dipstick of a DOF equipped car versus a non-DOF equipped car after a hard run should go a long way towards answering this question. I, for one, encourage Pedro to produce a video checking the oil of two comparable cars (same vintage, mileage and with fresh oil of the same type) after comparable on-track drives. Common sense, IMO, also suggests that, after the initial start-up of a DOS system, air cannot enter the bearing housing as it is a sealed system: by definitioin, without air there cannot be aeration of the oil.

Is the IMS solution an upgrade over the original sealed IMS bearings? Undoubtedly. Is it also a significant upgrade over a properly lubricated, unsealed, ceramic ball bearing IMS bearing? Possibly - although in the case of dual-row bearing engines with upgraded ceramic bearings and improved lubrication, the 'solution' will have to be unbelievably durable to get better results over time.

Considering the cost, at this stage I still believe that using an LN ceramic bearing and splash lubrication is the way to go for most people - certainly for those with dual-row bearings. I am also inclined to believe that for the larger single-row bearing equipped cars (where the bearing cannot be upgraded without engine tear-down), removing the outer seal is an essential first step. However, for these engines, I believe that DOF is the way to go. Whatever theoretical risk there is of aeration should be overcome by dramatically reducing the known risk of IMS failure due to inadequate lubrication. Finally, with more evidence on the issue of aeration, I would also think that DOF and an upgraded bearing would be the most cost-effective fix for the remaining cars, rather than merely an upgraded bearing.

If money is no (or virtually no) object, then I would go with the LN Solution. History from Porsche's own non-ball bearing IMS cars has proven it to be a reliable component design that should all but eliminate the worry of IMS failure. If only the M96/M97 engines had been designed that way in the first place!

Brad






-

IMS bearing failures have dozens of contributing factors that we have discovered. There's probably just as many that we haven't discovered yet.

If we knew all about it, what I do wouldn't be called research.

Southernstar... wow great summary and analysis!

I can buy the multiple failure mode theory. Seal failure leads to a lack of lubrication. A lack of lubrication leads to increased heat, pitting, wear, failure. How much surface area you have affects how quickly you realize failure - single row bearing thus will fail quicker than a double row, etc. The argument back and forth about whether it is a bearing load failure or a lubrication failure sounds a lot like the argument about which came first, the chicken or the egg. I looked at LN's website and see that they recognize the lubrication issue certainly as a contributor. It does seem then like the best solution would be the biggest, strongest bearing that you can fit with good (DOF) lubrication.

Personally, I understand the bearing weakness argument, but I just don't buy it. It seems to me that a steel bearing with proper lubrication should last just fine. That's my opinion and I think that's what I'm going to do with my car - steel bearing, outside seal removed, DOF. Will I still change the bearing with clutch changes? Honestly, yes I probably will, but mostly because it's just cheap insurance for me personally. I do my own work, so the extra labor cost is zero and the time won't be bad. I also buy a LOT of bearings at my work and can get the steel bearing for the same cost as a good lunch.

I'm not really concerned about oil getting into the shaft. Most people removing their IMSB have found oil in the shaft. It happens. It doesn't seem to be an issue. With the DOF at least that oil would not be stagnant.

I'm not really concerned about aeration either. If you look at the videos and good pictures of where the IMSB is installed you'll understand that it is a very, very tight place. That's why I don't like the splash lubrication approach... I don't really see a good path for oil to get into the bearing. Sure, maybe while the car is sitting and oil has drained back and filled the sump. But with the car running, oil pumping sloshing and moving about, I don't see a consistent, reliable way for oil to lubricate the IMSB. That's why LN uses a high wear bearing. The beauty of DOF is that it takes a lot of variables in lubrication out by providing a consistent flow. But you're pumping this oil into a very tight space. What's going to happen? The void is going to fill with oil, you'll probably even get some backpressure in the oil hose, and the excess will seep out of the small gap between the shaft and case. How is a lot of air even going to get in there? The bearing will be flooded and it should be happy.... then I'm happy. :p

Kirk

So Jake... if we guess this super secret factor will you confirm if it is correct or not? I have seen Charles Navarro of LN state that he would take this secret to his grave!

I am going to throw out my guess and I am going to bet that I am spot on.

The issue is that in the design of the intermediate shaft the ball bearing application is compromised (not optimal) and the magic number (or constant) that it is compromised by is 20%. We state load numbers for the 6204 bearing based on manufacturer's numbers, but those numbers assume that the inner race of the bearing is turning. In most applications the inner race is fitted to a shaft through an interference fit, the shaft rotates, the inner race rotates, and the outer race is held in place in a fixed housing. Bearing load numbers are based on this scenario.

This is not what happens on the intermediate shaft though. That scenario is exactly the opposite. The inner race is fixed and it is the outer race that is pressed INSIDE the intermediate shaft that rotates.

So who cares if it's the outer race that rotates rather than the inner race? Engineers care because this one little difference has a significant impact on how much load the bearing can take. The general rule that is used in bearing calculations is that the impact is a 20% decrease in load. Decreased load effects calculated bearing life and failure rates.

Is this significant then? 20%? Damn straight that is significant. So how to address this? LN went to a stronger ceramic bearing with a much higher load rating than OEM. But eventually LN went to a plain bearing with significantly different load characteristics altogether.

So what do you say Jake? Do I get the gold star??? :dance:

Kirk Bristol

LN Engineering didn't...

IMS Solution LLC did. LN doesn't sell the IMS Solution, neither does Flat 6 Innovations.

Kirk,

Thanks for pointing out the bearing life factor. Do you have independent calcs on IMS bearing life utilizing the 1.2 factor? I'm deciding what to do with my IMSB right now and have not had time to do more than look up the 1.2 factor for rotational arrangement. I'll run the calcs later, but would like to see a second set to verify my work. This may have a big impact bearing selection.

So you are saying that LN and Flat 6 had nothing to do with the development of the IMS Solution??? :rolleyes: Just because you started a LLC to cover your other businesses from liability lawsuits means very little if it is still the same people (George Navarro and Jake Raby).

Jake, you didn't answer my question though, do I get the gold star for exposing your super secret, the one that Charles was going to take to his grave???

I can see how this is significant. It should have had an impact on the class action suit against Porsche as their DESIGN is flawed and compromises the bearing! I can also see why Feelyx's idea got bought out for a patent. Yes, he was working on a direct oil feed system, but that's pretty straight forward. The main project he was working on was moving the bearing out of the shaft. He was focused on using a bigger bearing, but his design also moved the rotational point from the outer race to the inner race. I don't know if he realized that this one change would increase the life of the bearing by 20%.

Who has done an IMS change (New Oil Fed Design Idea) - Pelican Parts Technical BBS

Kirk Bristol

This is just another piece of the very complicated puzzle. When we first started looking at this problem, the use of the bearing in outer race rotation was one of the first problems I knew exactly how to tackle. That's the reason for a ceramic hybrid bearing with sintered silicon nitride balls to be specific.

Jake and I have been using sintered silicon nitride for various components including lifters in pushrod Porsche engines primarily for their wear performance, but the added weight savings is huge.

Now consider the reduced mass of the ceramic balls and how that relates to the loads exerted on the races during the constantly varying acceleration and deceleration of the IMS bearing. This is even more important considering the load on the IMS bearing isn't even across the whole circumference of the races. Since the sintered silicon nitride balls are only 40% of the weight of equivalent steel balls, centrifugal force is lower - the lower weight of silicon nitride balls enables rapid accelerations and decelerations with reduced wear.

At any given time a very small surface area of the bearing is carrying all the load. To simplify what's happening, the balls are slung round 3/4 of the circumference of the bearing and they go from unloaded to fully loaded with only 1 to 2 balls carrying all the load. This is why we see flat spotting of the balls and skidding in the races leading to pitting and eventually complete bearing failure.

Integrated Reliability Solutions

Considering the bearing is in outer race rotation and already prone to skidding, this is just one of the reasons we chose against roller bearings from the very beginning and focused on ceramic hybrid bearings.

However, I will clarify that just going to a ceramic hybrid doesn't give you a higher load capacity than an equivalent conventional bearing but their benefits certainly outweigh the cost.

Hybrid Ceramic Bearings | Applied.com

PS. George is my dad. He used to work in the aerospace field in sales and he came to LN a few years ago to help my wife and I.

James, I'm not trying to design a new bearing for this application, so I have not run any calculations. I have no interest in providing any competition for LN, IMS Solution, Flat 6, or TuneRS. I am just searching, exploring, discussing, and even arguing about what is the best fix. It's difficult though because there is money involved here and some people are pushing their products with pretty hard sales methods. You have to read what is out there pretty carefully.

For example, IMS Solution has this statement on their website:

"By replacing the factory sealed ball bearing with a pressure fed oil-lubricated plain bearing, the IMS Solution eliminates potential damaged caused by foreign object debris, eliminating 11 wear components from the assembly."

I think this is misleading at best, but more likely deceptive. 11 wear components are eliminated, really? I call baloney on that one in a heartbeat. The bearing is eliminated and the weak shaft that presses into the inner race of the bearing is eliminated. So what are the 11 components then? Well this is an extreme stretch, but I honestly think they are counting the eight individual balls in the bearing as being separate "components", the inner race, the outer race, and then the shaft = 11. When Porsche assembled these engines though they only bought two components from suppliers - the bearing and shaft. Calling that 11 components to try to make the change seem more significant is baloney.

So tread carefully and try to sift through the baloney.

If you want to post your calculations for sizing a bearing, feel free to. I am sure you can get some good feedback. You are limited though simply by what will FIT inside the IMS. If you look at off-the-shelf ceramic bearings be careful about the cage material. Most use a nylon cage. I don't believe the IMS Retrofit does. I believe that is what makes their bearing "custom" is that it probably uses a steel cage or some other metal. I would check the temperature rating for the nylon cages that are standard on ceramic bearings. I don't believe they will hold up in this environment and I believe that is the main factor that stops most folks from just grabbing any old ceramic bearing and selling it as an IMS fix.

Kirk Bristol

bad choice of words
 

Kirk,

While I have enjoyed this thread and the depth of the discussion. I do feel that your few use of words discount this thread and your your participation. :mad:

Thanks Charles, the information you provided is very helpful!!!

I do have one question that has been bugging me. Looking at the Applied website that you provided you will see that they recommend grease first and foremost for ceramic bearings, but that's not practical in our application as the grease would need to be changed very regularly. In that situation they recommend oil lubrication and they note that a ceramic bearing does not need as much oil as a steel bearing. However, lubrication is still key. The LN Retrofit relies on oil bath and oil splash lubrication, which Applied notes is fine in some applications. However, they also note that oil jet and circulating oil are also acceptable.

So what if someone does not feel comfortable with the LN Retrofit approach? What if they think that oil bath/splash in this application of high RPM's and high heat is marginal and that a more consistent oil flow is better? What would be the problem with a direct oil feed to a bearing like the LN Retrofit? The LN Retrofit website discourages this practice:

"The LN Engineering IMS Retrofit kit should not be used with any forced oiling products for which they were not designed for."

But ceramic bearings in general are designed for all forms of oil lubrication. Since you are providing some technical detail regarding your ceramic bearing would you mind providing some better detail on why the LN Retrofit does not work with direct oil feed?

Kirk Bristol

Sorry if I've offended. I've edited my post to tone it down. :D I get too passionate when it comes to engineering and technical discussions. I just love this stuff!

Kirk

All is good...:)

Kirk,

I'm not trying to design anything to sell. I'm just looking for an IMS redesign that provides adequate bearing life and addresses the root cause of the bearing lubrication failure. Your 20% discussion points to inadequate design by Porsche. Doing the calc on the existing bearing answers the L10 question.

Those 8 balls inside the single row IMSB sure do become "individual components" when they are expelled into the engine oil and create engine wide collateral damage.

Kirk,
You are not the first to point out the outer race rotation Vs inner race rotation. No gold star yet.

I am with you. Okay, I think I will do some calculations this next week too. We know the load ratings for the NSK stock bearing. I posted on Pelican Parts a link to the SKF bearing calculator that makes it easy to get an L10 calc. This assumes that the inner race is moving though. I suspect you can just multiply the results by 0.8 to get an answer for the outer race rotating.

SKF Bearing Calculator

You can use the numbers from the stock bearing to compare to other options. I believe I have seen LN post their ceramic bearing load figures in a forum post. You will have to "assume" a certain level of radial and axial loads. Thus you won't get a definitive answer, but you will get calculations that you can use to compare the options available.

The one variable I don't know is what TuneRS is using for their ceramic bearing. What is the load capacity of that option? Does it use a nylon cage? I plan to call Mike at TuneRS next week to ask these questions and add it to the mix for comparison. I want to include them because, although I am still investigating, my gut feel right now is that the TuneRS DOF with ceramic bearing is the best "bang for buck" option that I can install myself in my own shop. If the radial load rating of their bearing is good and you've got consistent oil feed, then it seems that this solution would address the major failings of the stock bearing.

Kirk Bristol

The things that motivate the DIY installer are quite different than those who are looking for an installation program and a Certified Installer to carry out the process. The majority of those reading these threads do not have the proper resources to carry out a DIY IMS intervention process, no matter which of the technologies will be employed.

We made the decision long ago not to support DIY installations and to do whatever possible to have Certified Installers apply our technology. Its no fun having to travel across North America as a WTI Instructor, and its much less fun to host my "M96 102" classes here at the Flat 6 Innovations 2-3 times per year to train the installers and evaluate them. It puts such a hiatus on R&D and engine assembly that I am having to build yet another training center off site to support these classes.

While there are other technologies on the market now, none of the others offer a true program for the installers.

Kirk, you are a fairly sharp individual. You are one of the few who I believe could carry out a successful DIY of most any IMSR intervention. I don't hand out compliments, they have to be earned.

To me, this whole DOF debate is really simple. If one sets aside all the theorizing about why IMSBs fail and starts from the point where one has installed an unsealed ceramic replacement bearing, the DOF question boils down to these two questions:

1. Does DOF substantially extend the operating lifetimes of unsealed ceramic replacement IMSBs compared to ones lubricated by being submerged in sump oil and splash oil?
2. Does DOF create additional risks to engine and IMSB longevity and reliability?

No one that I know of has put a number on the table (or even an estimate for that matter) that answers the first question. If the answer to the first question is "no" or "not by much", then one doesn't need to know the answer to the second question because it wouldn't make sense to take the risk.

thom, what numbers do we have for the longevity of unsealed ceramic bearings using splash oil ( I mean, apart from the recommended replacement at 4 years/50,000 miles)?

Brad

Spot on. How does spraying oil at a bearing extend it's life when it is already submerged or at the worst case scenario, partially submerged in oil in a crankcase filled with oil being whipped around by the chains?

Jake and I researched all our options as far where to supply oil for the IMS Solution and the only location we found suitable that didn't adversely affect operation of the engine was from the spin on oil filter adapter, which thankfully we had already developed and gone through the whole patent process years ago knowing we would be using it for such a purpose later on.

Whatever data we have is empirical evidence gained through the many years and thousands of bearings we have installed and serviced. Without any precedence for bearing life, we had to give our best guess for what would be a conservative service interval for these bearings. We now know that the dual row, triple row, and later 06-08 bearing, when upgraded with one of our IMS Retrofit or IMS Upgrades, is likely a permanent fix to last the life of the engine (or until something else fails in the engine).

As far as the single row IMS Retrofit, we've seen many easily clear this 4 year, 50,000 mile interval with zero issues. We use the same single row bearing as part of the bearing stack for the triple row IMS Upgrade and with over a 1000 of those in service with zero issues- the bearing itself isn't an issue. However, there have been some limited failures of the single row bearing.

We know that of the failures we've seen, most of them can be attributed to installation error, but that aside, I know that there have probably been an equal number of improperly carried out dual row IMS retrofits and those haven't had problems. Case in point, we have seen several dual row bearings that were installed in engines where the original bearing had failed. Even with extensive cleanup of the sump and many oil changes, contamination from the original failure damaged the replacement bearing, but they keep running and don't fail, whereas, when the same was done with a single row, they almost immediately fail.

So if all these other ceramic hybrid bearings have been working flawlessly with zero failures only with lubrication from the sump, what conclusions would you draw.

The single row bearing by itself has the lowest load capacity. The bearing's lack of load capacity is the only variable here.

Granted, many single row bearings last well over 10 years/100,000 miles with no problems where others fail much sooner. There are lots of variables affecting bearing life, all of which have been discussed at length over the years. Although the IMS Retrofit with the single row 6204 ceramic hybrid bearing addresses many of the issues of a conventional ball bearing in this application, the issue of load capacity is one that could not be addressed with a direct replacement until we released the IMS Solution and which will be addressed next year with the next generation of IMS Retrofit.

I for one won't won't be happy until we achieve a 100% success rate.

L10 life of the 6204 bearing is 90,000 miles assuming an average speed of 60 mph in top gear (the speed mph isn't really what is important - it's the engine RPM that is as engine rpm is directly related to IMS rpm to ball bearing life). Driving habits play directly to this.

How does adding more oil to a bearing that is already submerged address the major failing of the stock bearing and furthermore constitute being the best bang for the buck?

This is one of our tests to qualify an IMS for our upgrade procedure. If the shaft has more than .005" of runout on the main sprocket, we fail it. Most shafts however don't have any. Only when the shaft has been subjected to an IMS failure or some other kind of trauma (broken chain), is it that we see runouts starting at .015" and only getting worse from there.

The other issue we check for is concentricity of the bearing housing bore as well as runout and taper. Most usually have a few tenths, but we've seen some that have several thousands when the sprocket has zero runout and in those cases, we will junk those shafts too. Unfortunately, this is all stuff you can't easily check for when the intermediate shaft is still in the car and specifically why carrying out a retrofit procedure on a bearing that has failed or is close to failure is not advised (excluding the foreign object debris that has already compromised the engine and will compromise the replacement bearing).

Is the IMS bearing submerged? I thought I had been told it was mist lubricated.

The only time the IMS would be lubricated by mist would be if the engine is suffering from oil starvation. The IMS is located well below the where the oil level sits during normal operation in the integrated dry sump (i.e. wet sump).

Charles, the successful history of your ceramic bearing upgrade is precisely why I recommend the same for all except: 1. those with unlimited budgets, for whom I suspect that the LN Solution would be the way to go (in spite of the relative lack of vehicles on road to prove the technology); 2. those with the large single bearing who cannot upgrade the bearing without an engine tear-down. For those I would suggest that DOF lubrication of the original bearing, even if there are minor risks of aeration and oil pressure loss, would be better than leaving in the original bearing and hoping that it lasts now with just the removal of a seal.

I wonder, however, if a dual standard is not at play here. When LN introduced the ceramic bearing upgrade, customers installed the same even though they had not yet been proven in large numbers over a long period of time. They were convinced by the initial testing and the inherent logic of the design - something which you and others are now suggesting would be inappropriate for prospective customers of DOF technology. What is more, your new 'solution' is also not supported by a large number of installations over long periods of time. To remain logically consistent, doesn't that mean that the upgrade should also be preferrred to the solution because of its proven track record?

Brad

In this discussion we've tried to focus on facts and what has been proven through testing. I believe this view though that the IMS bearing is well lubricated without the seal through oil bath or splash lubrication is an assumption not based on actual testing. It would be pretty hard to measure, but I don't think the actual sump level has been measured through the dynamic loads that a car would see during normal driving. I would like to see any data that has been collected, if this has been done.

As such, I personally do not hold to this assumption that the bearing will see adequate lubrication with simply the seal removed. What I have seen, on the contrary, points to mediocre lubrication at best. Seeing is believing though and this is what I have seen, stolen from Feelyx on Pelican Parts:

http://986forum.com/forums/uploads01...1382389089.jpg

The intermediate shaft sits up relatively tight against the engine case, allowing just a small slit for oil to get through to lubricate it from the sump below. Some oil will fall off the chain from above, but will still need to get through this small slit. This picture does not show the cover that would further block flow of oil through splash lubrication to the bearing.

http://986forum.com/forums/uploads01...1382389219.jpg

http://986forum.com/forums/uploads01...1382389244.jpg

Some more pictures of different views further illustrating this point.

So, would I depend on splash lubrication for this critical bearing? Absolutely not!

But what about oil bath lubrication? Maybe the bearing is partially submerged...

http://986forum.com/forums/uploads01...1382389365.jpg

http://986forum.com/forums/uploads01...1382389396.jpg

These photos from Feelyx again show where the oil bath is located. Obviously the chain was designed by Porsche to be lubricated by an oil bath. The IMS bearing was not.

So how much oil does the bearing get then if you just remove the seal? The truth is that we don't really know. LN Engineering "assumes" that it is enough. I personally look at the location of the bearing and I do not come to that same conclusion. Instead, what I am willing to bet on is having a good, consistent flow of oil directly to the bearing - direct oil feed. With DOF there is no guessing, no assumptions, you KNOW the bearing is going to get enough oil regardless of how much oil is in the sump and regardless of vehicle dynamics (hard braking, hard cornering, etc.). With a very expensive engine on the line and a car that I love, I am going to trust something that is a lot more certain and consistent - direct oil feed. This is why I've been such a big proponent of the DOF system - it just makes sense to me!

Kirk Bristol

Given my last post with the photos I will pose this question again... if I don't feel comfortable relying just on oil bath and oil splash lubrication, what is wrong with direct oil feed to a ceramic ball bearing - specifically the LN Engineering bearing??? Wouldn't the DOF allow the bearing to run with less wear and cooler? Wouldn't it remove variable lubrication and make it more consistent? These all seem like good things to me, and I really can't see aeration and system pressure losses as being significant down sides. So what exactly is the problem with DOF on a ceramic bearing?

Kirk Bristol

Time and studies will tell.

Kirk, It sounds like you've made your mind up. I believe that decisiveness is a key to anything, so it looks like stage 1 is complete for you.

Charles and I had our version of the DOF in 2007, the studies that we did then, and the data that we collected are the reasons why we do not support a DOF when being utilized with the LN Ceramic hybrid bearing. We did this when having a difficult time extracting OEM dual row bearings, hoping that it would be an alternative to a retrofit, which at the time seemed was not an easy process.

The mistake we made then was not patenting the procedure. We've learned from our mistakes, and trust that from this point forward we'll not only protect the things that we plan to bring to market, but also competing technologies, even if we don't prefer them, or have any plan to bring them to market.

Let us know how the DOF install goes.

Been there and done that before... Remember, we were the guys getting chastised here on the forums for "a retrofit" back in the day. Back then any retrofit wasn't accepted and people basically made these same statements about anything that we did. Thats what happens when you pioneer something.

Does anyone believe that Porsche even remotely looked into any other solution when they updated once again the 06 and up IMS bearing design.Simply installing a larger bearing seems pretty limited outlook for thease world famous engineers it seems.If they had already dropped near 20 million in warranty claims before the law suit even surfaced i would have thought that they would have put there best tech on that one. Apparently not !! I love my car (06 boxster s) but if i had to do it all over again,i wouldent touch an IMSB Porsche auto.Worth noting is i contacted my Porsche private shop that are very well established in ontario,Canada to ask if he could install one off thease systems and cost,he told me not to waste my money and the whole IMS issue is blown out off proportion.Strange! I am sure those that have suffered the financial loss don,t feel that way.By the way Porsche lawyers did contact his shop for a customer list for which he declined.

What do we know about what happens if you remove the seal?

With product H we have a use the OEM part but remove the seal process. Done in the UK and done for several years. Unknown quantity and unknown miles and unknown analysis of long used bearings. UK forums not full of failure reports.

With product N we have a ceramic part and remove the seal. Lots out there and comparatively lots of years and miles. The forums aren't full of failure reports so we know at least something. Not the ultimate shape of the failure curves but something out to 50k.

With product C we have something similar to the N but small quantities.

And then there are two pressurized oil lubed bearings that are both different in their lubrication method but how many have been used and under what conditions? We have no data. Not even the sketchiest.

Since someone are doing an IMS to reduce risk, how much added risk is there to using one of the lesser known-about products even if their logic appeals to you?

Isn't the one common thing about the two approaches that have been in the wild for the longest that they use the "remove the seal" approach? Doesn't that tell us something about them getting enough lubrication? Maybe not enough to last forever but for a long time?

Good feedback Mike but that brings me back to same question then why did Porsche not use that same procedure and remove one seal off the bearing,whay through another sealed bearing in,they have to have a good reason not to.

By that time the 9a1 was already a reality. They knew that the crankcase would go away in 2008, and the easiest way to address the issues that were occurring at low engine speeds was to increase bearing diameter, increase surface speeds and reduce load the bearing sees.

Reinventing the wheel for only 2-3 years didn't make any sense. They didn't even alter the crankcase, if they did we'd be able to retrofit M97 bearings, too.