Pedros Techno DOF IMS fix?

[Jake Raby]

All,
Charles and I are both tied up today, and all weekend with Porsche DFI engine developments.

Our responses will be posted on Monday.

[Steve Tinker]

Exactly what I said in #101 above..... the LN ceramic bearings are "very happy" in their splash / mist lubed enviroment.
And heres another hypothetical: how many people are going to own their Boxster / Carrera for multiples of 50,000 mile bearing chnges? Not many I suspect.
Other failures are going to take these cars off the road long before the original LN ceramic bearing fails.....

[southernstar]

Charles, once your bearings are sold and installed, surely it should be up to the owner whether he chooses to improve the lubrication of the bearing. Are you really suggesting that increased oiling of the bearing will lead to its failure? I can understand, if not necessarily agree, with your expressed concerns over the effects of DOF upon lubrication elsewhere in the engine, but as regards IMS bearing durability, your comment seems to be nothing more than a scare tactic intended to undermine a competing technology. It would be one thing to say in general terms "we do not recommend the installation of DOF" - we all know and understand that. It is quite another to say that DOF is NOT to be used with any LN Engineering Retrofit kit: that implies that it will cause damage to the bearing (or at least, your bearings). If a customer such as Kirk has chosen to upgrade the bearing AND install DOF based upon his own analysis, so be it. If the bearing subsequently fails, he will have much more to worry about that claiming the cost of your bearing.

In any event, I am beginning to see why TuneRs has tuned out of this discussion. At the very least, seeing as you are implying that DOF will lead to premature IMS bearing failure, don't you think it would be appropriate to give us your reasons?

Brad

[JFP in PA]

Originally Posted by southernstar

Charles, once your bearings are sold and installed, surely it should be up to the owner whether he chooses to improve the lubrication of the bearing. Are you really suggesting that increased oiling of the bearing will lead to its failure? I can understand, if not necessarily agree, with your expressed concerns over the effects of DOF upon lubrication elsewhere in the engine, but as regards IMS bearing durability, your comment seems to be nothing more than a scare tactic intended to undermine a competing technology. It would be one thing to say in general terms "we do not recommend the installation of DOF" - we all know and understand that. It is quite another to say that DOF is NOT to be used with any LN Engineering Retrofit kit: that implies that it will cause damage to the bearing (or at least, your bearings). If a customer such as Kirk has chosen to upgrade the bearing AND install DOF based upon his own analysis, so be it. If the bearing subsequently fails, he will have much more to worry about that claiming the cost of your bearing.

In any event, I am beginning to see why TuneRs has tuned out of this discussion. At the very least, seeing as you are implying that DOF will lead to premature IMS bearing failure, don't you think it would be appropriate to give us your reasons?

Brad

Actually, I believe that Charles has said that the design of the DOF flange is too thick (see Pedro' s published photos) to correctly obtain nut engagement and torque loading on the LN bearing, which is a real issue on IMS bearings, OEM or after market. Improper center bolt torque is a common source of IMS retrofit problems. Secondly, there is a real concern about how the oil is being fed to the bearing and how debris free the oil is when it enters the bearing, again regardless of what type bearing it is. Anyone that has disassembled one of these engine's can appreciate this concern.



The DOF system may or may not be a good design; but in lieu of significant test data on a large sample of cars, only the passing time and a large number of installs will tell. Unfortunately, this entire dialog reminds me of another very similar one were a poster that apparently botched the install of an LN retrofit choose to both denigrate LN and shout the praises of another aftermarket retrofit company's system, right up until his engine grenaded from an IMS failure. Opps.........

Rather than taking up sides, I think readers need to be aware of what is available in the market, and if concerned read everything that they can get their hands on about the subject. Generally, there are usually at least two side to every story, sometimes more. Some people, those that are less risk adverse, are going to be "early adopters" of new technology, others may choose to take a more wait and see position; both of which are completely justified. Currently, LN has the market based upon history and a very large base of successfully installed units, they also have the confidence of a large number of shops that do the installs. To be successful, the DOF system has to accomplish the same market penetration and earn that level of confidence. All the internet postings in the universe is not going to change that.

[southernstar]

Thanks Jeff, I had not read the expressed concern over the thickness of the DOF flange. I can see where that could cause issues if: 1. an identical length bolt is used, and 2. the flange has not be designed at the point of entry of the bolt to be used with an identical length of bolt (it is surely not the additional thickness of the flange per se, but rather the thicknes/spacing at the point of entry of the bolt that would effect torque). A very good question and one to which I have not read an answer.

As to the other point, if there is debris in the oil passages of the engine, then no doubt there will be various problems for every component of the engine including cam shafts, valve train, main bearings, etc.



Brad

[JFP in PA]

Originally Posted by southernstar

Thanks Jeff, I had not read the expressed concern over the thickness of the DOF flange. I can see where that could cause issues if: 1. an identical length bolt is used, and 2. the flange has not be designed at the point of entry of the bolt to be used with an identical length of bolt (it is surely not the additional thickness of the flange per se, but rather the thicknes/spacing at the point of entry of the bolt that would effect torque). A very good question and one to which I have not read an answer.

As to the other point, if there is debris in the oil passages of the engine, then no doubt there will be various problems for every component of the engine including cam shafts, valve train, main bearings, etc.



Brad

To be completely fair, Pedro has stated that they are now making a flange that will allow better engagement of the center bolt, but I do not know what other impact thinning out the center of the flange will or won't lead to. The DOF would appear to be a "work in progress" that is still working out some of the kinks you get with any new product launch; very few ever go to market cleanly, but that is the essence of product development.

[Ckrikos]

I love a good IMS discussion. Just think what would we be talking about if not for the IMS.

[mikefocke]

You presume, since the LN ceramic was chosen and designed and modified (they got at least one wrong the first time but that was long ago) by a retired bearing engineer and Porsche nut, that there was a reason why they used the parts and designs they did. You also have 10k of owner's experiences to tell you a little about how well they chose. So deviating from that would seem to require some theory, study, test, experience...wouldn't it?

Now if you want to run the experiment on your engine, why it is your engine.

[Nine8Six]

This is going on and on and on LOL

I can see a lot of member bragging about their engineering background but can't see anyone throwing any sort of stress-strain curve vs (x)modulus formulas designed for bearing type selection, materials and applications :/ Fascinating thread otherwise!

As little as I know on anything related to cars.... fuel dilution, glycol, calcium sulfonate contamination are the main cause of engine's internal parts/premature failures. Bearings and seals being mostly at risks. OIL BALLS anyone?! Why would anyone give a bearing more of that would be my first question.

Personally, I have better things to do than worrying about a dumb bearing, or a cheap engine (this is not a Ferrari or a Lambo!). I do however ensure to carry out the regular maintenance on my little 986 roadster, have the fuel injection system, MAF and O2 sensor system functioning spot-on at all time, use PORSCHE APPROVED OILS, and my engine (and bearings) simply works as the "professionals" engineered it. Make sense?

Some of the best bearings (perhaps overkill) in underground motorsport designs are made with TI(Ti-6Al-4V) races, 316 stainless steel balls, packed with solid oil, and sealed to prevent "contaminations". Already public info in case anyone really care to come up with a warranty for 50 years bearing (simple) design.... by all means be the Porsche engineering team's savior!

[Jamesp]

I had not heard of Ti-6Al-4V so I looked it up! "Ti-6Al-4V's poor shear strength makes it undesirable for bone screws or plates. It also has poor surface wear properties and tends to seize when in sliding contact with itself and other metals." Sounds like exactly the thing for a bearing. I'll take 2

[Nine8Six]

I'll take 4 (four) of those NSK steel-on-steel ball bearing then. Those have the same coefficients of friction in both static and kinetic values as of rubber on asphalt! I believe TI is used for its thermal, durability and non-toxic properties. Properly done, ssteel can be harden far beyond TI... those balls are the ones that carry the load capacity if my memory is good.

I just heard some young dudes talking about this in the R&D center I worked for 20+ years. I was just their janitor mopping floors all day long and know nothing about nothing sorry for wasting your time!

[thom4782]

Brad:

Nobody, including the LN developers, is denying that compromised lubrication did not play a role in IMSB failures. It probably was the root cause of most dual row OEM failures and about 1% of the single row ones. Poor lubrication doesn't explain the other 7% of single row OEM breakdowns. Weaker load carrying capacity probably does because that's the one key difference between dual and single row designs.

People need an answer to a critical threshold question before choosing between LN Retrofit or a DOF lubricated unsealed bearing, namely is lubrication still a problem for unsealed replacement IMSBs?

The LN data makes a strong case that the answer to the question is that there is no lubrication problem for unsealed replacement IMSBs. Not surprisingly, one DOF developer regularly says that lubrication is still a problem but he doesn't offer any hard facts to support his view.

Thom

[howe]

Something interesting as a comparison w.r.t. lubrication of deep groove ball bearings.
ROTAX 582, water cooled 2 stoke engine run 6207 and 6206 DGBB's on their crankshaft @6500 RPM,
Lubrication? 50:1 pre mix, that not a lot of oil.

[southernstar]

thom, if you read my posts you would see that we are largely in agreement: for example, in post 84 I suggest that for owners of the double-row bearings, the LN retrofit is the most cost-effective answer; for those with the single-row bearing, I opine that is likely also the case, although WITH BETTER EVIDENCE, I suggest that the DOF may also prove to be an important augmentation to a bearing upgrade/replacement.

We know that the dual-row bearing is more durable than the single row. We also believe that a properly engineered ceramic bearing should be more durable than a steel one. Finally, we know that inadequate lubrication is a causal factor in IMS bearing failure, regardless of the type of bearing. What we do not know is whether, especially for the single-row bearing, splash lubrication will be sufficient to ensure trouble-free, long term use. It would seem that LN are also unsure, in that they recommend replacement of their upgraded bearing every 3 years, or 50,000 miles. I wonder how many of the original sealed single-row bearings would have failed if replaced on that schedule!

Brad

[JFP in PA]

[Jake Raby]

It would seem that LN are also unsure, in that they recommend replacement of their upgraded bearing every 3 years, or 50,000 miles.

We are quite sure.. Absolutely positive, that the issue is not lubrication.

The single row retrofit bearing is recommended as a 50K component due to it's size and load carrying capacity- nothing more.

The single row bearing simply is not robust enough, even when superior ceramic balls and hardened races are utilized. Two rows are certainly better than one.

[southernstar]

JFP, to you it may be a dead horse, but to others it has been worthwhile discussing the various bearings and the lubrication of the same. Jake, we all now know that dual-row are better than single-row and Porsche's own numbers verify the same. Indeed, it seems that your own opinion on the same has also evolved over the years for, as I recall, a couple of years ago your opinions in that regard were much more circumspect.

Nevertheless, if lubrication is a contributing factor to IMS bearing failure (and I thought we were all in agreement on that as well), then does it not also stand to reason that a better lubricated bearing should outlast one with poorer lubrication?
You believe that splash lubrication with seals removed is not only adequate, but better than DOF for various reasons (aeration of the oil, etc.) and you may be right. Only time and further testing will tell.

Regardless, my understanding of the issues has been enhanced by this thread and I strongly suspect that the same is true for others. JFP, if it has been tiresome for you, so be it. Anyway, barring some new and unexpected news/information, I'm certainly out of here.

Cheers!

Brad

[JFP in PA]

Originally Posted by southernstar

JFP, to you it may be a dead horse, but to others it has been worthwhile discussing the various bearings and the lubrication of the same. Jake, we all now know that dual-row are better than single-row and Porsche's own numbers verify the same. Indeed, it seems that your own opinion on the same has also evolved over the years for, as I recall, a couple of years ago your opinions in that regard were much more circumspect.

Nevertheless, if lubrication is a contributing factor to IMS bearing failure (and I thought we were all in agreement on that as well), then does it not also stand to reason that a better lubricated bearing should outlast one with poorer lubrication?
You believe that splash lubrication with seals removed is not only adequate, but better than DOF for various reasons (aeration of the oil, etc.) and you may be right. Only time and further testing will tell.

Regardless, my understanding of the issues has been enhanced by this thread and I strongly suspect that the same is true for others. JFP, if it has been tiresome for you, so be it. Anyway, barring some new and unexpected news/information, I'm certainly out of here.

Cheers!

Brad

Let's see, Group A has an opinion based upon years of experience and thousands of successful installations, Group B has a different, and somewhat opposing opinion, based upon a handful of installations and a track record that can probably be measured in weeks. This is not even close to a fair comparison. Through most of this tedious debate, I have read a lot of speculation, supposition, hyperbole, and in some cases wishful thinking packaged as "a logical conclusion". Basically, those that support one view can not or will not accept the potential of the other, and visa versa.

If spraying unfiltered oil on the back of an OEM style steel bearing assembly truly is the future for the M96/97 design engines, in a year or two it may become more obvious, but right now it looks more like trying to develop a trend line from too few data points and a whole lot of arguing. Those of us that stake our business's reputation on how well an aftermarket part will perform will take a wait and see position until there is enough data to confirm its viability. And arguing and posturing is not going to change that.

[cheetah]

Just throwing this out there:

I work with very expensive rotating equipment everyday. A few years ago, we started converting most of our bearings from oil bath (either oil flung up by an oil ring or having a level of oil just slightly above the outer race at the bottom of the bearing) to an oil mist system. The oil mist provides the bearing with a very small mist of oil to be pulled through the bearing. Most people thought that there would be bearing failure because of lack of lubrication, but the data shows that this is not the case. This misting amount is so miniscule, hardly any oil at all.

Bearings do not need much oil to work properly and of course, too much is not better. They do need "good" oil though.

I am sure that Jake could test (maybe he already has) how much oil is splashed up to this bearing. It would show whether that was enough lubrication.

The only scenario where there might not be enough oil momentarily would be immediately upon start-up and under hard cornering.

My Boxster has a 3.4L from an 06 Cayman. So I have that huge, single row bearing. I talked to Charles when I bought the engine and since I didn't want to open an engine with 20K on it, he suggested that I remove the outer race. I did and have ran it that way for the last few summers.

[Kirk]

Originally Posted by JFP in PA

Let's see, Group A has an opinion based upon years of experience and thousands of successful installations, Group B has a different, and somewhat opposing opinion, based upon a handful of installations and a track record that can probably be measured in weeks.

I'm still at a loss as to why people question the benefit of properly lubricating a ball bearing... Yes, the DOF system is a new product and doesn't have thousands of installs, but the SCIENCE that it is based on is old and well proven. So why question it so much? Sorry for being so blunt, but I think it's time to call it like it is... I personally discount most of what LN Engineering and Jake Raby have said regarding lubrication not being the issue because Jake has made it very clear that he is out for blood in a fierce competition here. He's looking to crush alternative products. If there is real science that he wants to share to add to the discussion of lubrication, then add it. Instead we get vague responses about our AOS maybe failing...

I think the whole story on the importance of proper lubrication has changed. The IMS Retrofit website has been updated to sternly warn against direct oil lubrication now. Their UK distributor website hasn't been updated/changed yet though and it is very, very clear throughout - poor lubrication is the key contributor to the IMS failures.

PORSCHE Intermediate shaft upgrade kit for PORSCHE BOXSTER ENGINE 986 AND PORSCHE 911 996 ENGINE

The failure differences between single row 6204, double row, and single row 6305 bearings seem obvious to me. Without the proper lubrication what kind of problem are you going to have? Accelerated wear. Now if you have more balls or a bigger bearing will you be able to tolerate more wear before failure? Absolutely. So you would expect higher failure rates with the smaller 6204 bearing, but not because the bearing is so weak that it is failing due to low tensile strength. No, when we see IMS bearing failures we don't see shattered, broken bearing balls. What we see are worn races, worn balls, worn cages.

I don't need 12,000 installs and years of experience to tell me that proper lubrication is the best answer to wear. No, there are millions and millions of installs and decades and decades of experience that tell us that proper lubrication is the BEST way to minimize wear in a ball bearing. That's why I see the IMS Retrofit with a stronger bearing as just a band aid solution while the direct oil feed is a real fix, root cause solution.

Kirk Bristol