Jake, you are right that my mind is made up about the DOF. What I do will most definitely include the DOF. My big question is what kind of bearing will the DOF be spraying oil on??? I called Mike at TuneRS today and I am awaiting bearing data from him for what he offers. He made it clear though that he is not trying to sell a bearing solution. He is trying to sell a lubrication solution and leaving the bearing question mostly up to others. Your response though still leaves me looking for an answer. So you tested the DOF and found it unsuitable for your ceramic bearing, but WHY, WHY, WHY??? What is the reason, what did the data show? Doesn't the quote that Charles Navarro gave apply here?

Christopher Hitchens - "That which can be asserted without evidence, can be dismissed without evidence."

You make me think that there is no good reason not to do this by not supplying one.

Kirk Bristol

Sharing the things that we know about spraying uncontrolled oil inside the crankcase would be targeting and would be frowned upon.

What we did was not a DOF, as that is the name that they have chosen for their specific product. Essentially it was the same thing, and there are more than a few ways to do it, some better than others.

I was simply stating that we have first hand experience with this form of potential increased bearing life. That's where our standing comes from, not just saying "Don't apply the pressure fed oiling to an LN bearing because we said so".

Like anything else, time will tell.. In fact you may experience some of the things that we did yourself. Just pay attention and share your findings fair and balanced, good or bad. Don't stop analyzing after the install, watch oil consumption, fuel consumption and pull the hose from your AOS after a hard drive before and after the intervention. Pay attention to every noise and every smell. In fact remove the hose from the AOS and block off the port on the intake and see what happens after a hard drive before and after.

Moreover, run your engine at 6,000 RPM for 10 minutes and drain the oil immediately after it shuts off, then do the same test and install a cut off valve in the line feeding the oil flange. Then shut that valve off and do the same test at the same RPM and drain your oil and see what you notice. Then carry out UOA and compare before and after.

The majority of development is just paying attention; listen to the engine as it doesn't know how to lie and it will tell you what it wants and what it likes. Throw the engine on an engine dyno, or the car on a chassis dyno and shut the valve off and on between runs, or utilize an inline electronic fuel shut off to kill the flow of oil at WOT during a run and see what happens. When you do that you can integrate some transducers in the exhaust system and wee what you find then. Maybe you'll see something, maybe you won't and you have to be looking for issues when doing this, because everything is guilty until proven innocent- right?

You might waste your time and thousands of dollars, or you might find something that someone else hasn't.

What I stated here barely scratch the surface of the things that one would need to pay attention to when carrying out this sort of development. These kinds of things are all I do, all day everyday and it is enough to drive someone crazy. Fortunately I was already crazy before I started all of this.

Exactky. Your mind was made up before you even started posting.

The decision to reduce IMSB risk with what technology would be an easy one in a world of perfect information. That world doesn't exist for the Boxster community today and will not exist for years to come if ever. Owners can only rely today on the available empirical information and the opinions of the developers and other community members.

My calculus is simple...

1. The differential IMSB bearing failure rates documented in the class action law suit make it more likely than not that single row bearing weakness is the root cause of the majority of IMSB failures.

2. The LN Retrofit dual row real world experience over many years and thousands of miles make it more likely than not that it is a life of the engine fix as Charles opines.

3. The LN Retrofit single row experience suggests it is a long term fix, at least 50,000 miles, but its developers caution about inherent single row bearing weakness suggests it is a wear item that one should consider replacing at the 50,000 mile mark.

4. DOF may extend the worry free lifetimes of single row ceramic bearings far beyond wear intervals, but there is no empirical experience or developer opinion to suggest by how much.

For me, the above is more than enough to make an informed decision regarding how to mitigate risk. I don't find further hypotheses about possible failure mechanisms or the merits of one technology versus another helpful. They are speculative and their degree of correctness is unknowable without more data. And that's the beauty and curse of the scientific method - hypotheses are just informed guesses that beg confirmation through laboratory or real world observations before they are proved correct or not.

At the end of the day, each owner must look at the data, opinions and speculations that lie before him or her and decide for themselves if, when and how to deal with the IMSB risk problem.

Jake, I agree totally - the criticisms you received upon introduction of the retrofit bearing come with the introduction of any new technology that has not yet been proven on many vehicles over many miles in real world usage. It is the same criticism that is now being levelled at the DOF (and at the new IMS Solution).

I still maintain that for owners of double-row bearing engines, the retrofit is probably the most cost effective answer. For owners of single-row bearing cars, I suspect that the retrofit with your recommended replacement schedule is likely the most cost effective answer - although with better evidence on aeration, I would be inclined to see DOF as an important augmentation to a bearing upgrade/replacement. I also believe that for those for whom money is no object, the new IMS Solution is likely the best available technology, in spite of the fact that it has not been tested on the road by a large number of cars over a large number of years: the technology just makes sense to me. By the same token, I also believe that for owners of the larger single-row bearing engines, which cannot be replaced without engine tear-down, DOF seems like a low-risk upgrade. Lets face it, even if it leads to some premature replacements of the A/OS (and that is a big if, bearing in mind that the A/OS failures tend to be based upon failure, over time, of the internal rubber flap), it is much cheaper than complete engine replacement if the IMS bearing fails. As to minor oil pressure variances, again I believe that the engines were designed to accomodate significant variations in oil pressure as occurs naturally depending upon various factors such as oil viscosity, oil temperature, RPM's etc.

Customers who purchased your retrofit bearings at the time of their introduction did so not because it had been proven on many cars over many years, but because the technology made sense. Today, after many years and many units, that logic has been supported in real world usage. I believe that we are in exactly the same position today with respect to the introduction of the DOF and IMS Solution as those who originally purchased the retrofit: prospective customers must look to logic, risk, costs associated with those risks and the particular engine that they have. It may be, as I ssupect, that one size (or one solution) does not fit all.

Brad

From all of these posts going back and forth, here and other forums, it seems that the point of our product has become lost. We developed a lubrication kit for the IMS bearing (ANY type bearing, original or aftermarket, steel, ceramic, ball or roller), not a bearing replacement kit as some have said. We have a mechanical component in a harsh environment, with friction and inadequate lubrication – it needs proper lubrication and cooling to increase its reliability.

We don't normally get too involved in message boards because responses can often lead to situations like this. Our posts online in different discussion boards were mainly to answer a few questions from members and to inform the community of a fix for the bearing lubrication problem. Unfortunately there are some board members with competing technologies and a self-preservation agenda that would rather engage in character assassination as well as internet muscle matches than to actually discuss our oil lubrication kit for the IMS bearing. Like someone mentioned, “this is a PR nightmare for companies.” All this back and forth is just confusing Porsche enthusiasts and owners in regards to the whole IMS bearing situation, doing more harm than good to both sides.

In the very near future we will produce a short video explaining our product in more detail, introducing another new product and answering your e-mailed (through our website) or PM’d questions during the next 10 days.

Just picked up the Nov issue of Excellence magazine and read the article on IMS issues and the law suit with Porsche.Interesting to note the editors state that the best fix for 06 thru 08 boxsters and 911,s with IMSB is to just pull the trans,flywheel,clutch ect and remove the bearing seal and let the oil from the engine lubricate the bearing rather than wait for the lifetime grease to possibly wash out . I really love this mag and respect the info they offer.Are they engineers,builders,Don,t know but theres lots of ads in there mag this month on IMS fixes from many suppliers with different theorys BUT they don,t recommend any,just to pull the seal.They do state worth getting is the LN engineering oil filter/adapter because if the bearing starts to fail there is no bypass (as with the stock oil filter) and the metal fragments will not run thru the motor causing total destruction before hopefully noticeing it when doing an oil/filter change. This has been a really interesting and informative thread .
Warren

Exactly. This is the same thing that we are recommending and it seems to be more than adequate.

The larger M97 diameter IMSB has more load carrying capacity and is proving to be very resilient to lower speed performance in comparison to the M96 diameter bearing. This is the big difference as the surface speeds of the bearings is one of the main issues and the larger IMSB becomes unloaded at a lower engine speed than the M96 bearing diameter does.

Charles and I see no reason to provide fixes for the M97 IMSB, because the small amounts of failures that we see are immeasurable. We have made sure that our patents cover the M97 series engines and while we have already developed the components for them, we have no desire to offer them. We even have a version of the IMS Solution that can be retrofitted to the M97.

If I had an M97 car I'd pull the seal, use JGR DT40 engine oil, install a Spin On filter adaptor (to keep the oil free of debris and therefore keep the seal-less IMSB debris free) and change the oil every 6 months/ 5K miles. Then just drive it. You won't fine me making that statement for any M96 IMSB car.

[QUOTE=southernstar;368706]
Customers who purchased your retrofit bearings at the time of their introduction did so not because it had been proven on many cars over many years, but because the technology made sense. Today, after many years and many units, that logic has been supported in real world usage.

You are correct.

I had my LN ceramic bearing fitted back in 2010 when many people didn't know & didn't care about retrofitting the IMS bearing.
But I come from an engineering background, so the logic of the ceramics and the commitment in $$ portrayed by Navarro and Raby convinced me that it was a better solution than the factory original. Convincing enough for me to stump up close to $4,000 for the retrofit which to me is a serious cost for something you can't see, feel or hear!.
Does it really, really matter if the bearings are splash, force or mist lubricated - as southernstar says, many years & many units later they are still out there and working, so somethings right with the design ......

I don't know how much time, effort or dollars Flat6 and LNEng has sunk into the whole M96 bearing debacle (and probably they don't either), but you've got to give credit where credit is due - both Navarro & Raby will be bearing enough scars on their gonads to last a liftime - a bit like war wounds to be worn with pride.

This is a fantastic discussion on the IMS bearing. It includes opinions from folks like me with an engineering background and many engine rebuilds, but very little (say zero) experience with the M96 engine, other than tearing it down for rebuild. It also has experts who do this every day for a living. Perhaps a little self promoting to be sure, but usually with the caveat, "I am biased, but..." . I did not see any one beating on anyone's character, their product approach perhaps, but that is expected in the marketplace. I'm also not sure why anyone would view this string is a "situation", it's a free exchange of ideas, some good, some maybe not so good. It is up to the participants to decide what they think. I enjoy the spirited technical discussion, and would hope folks would contribute to it with their ideas and products. If you've got something to say, put it out there, we all want to read it. I've learned quite a bit about the IMS - the latest comment on low speed loads (a little hand tip perhaps?) supports a thought I had on lubrication viscosity. Lets keep the technical discussion flowing, and maybe we can get the technical experts to tip their hand a little more...

Jim

[QUOTE=Steve Tinker;369011] It matters in the following $350 sense…

The apples to apples trade off in rough price terms is this: the $650 custom manufactured LN Retrofit lubricated by sump oil versus the $1000 combination of an off-the-shelf ceramic bearing (@ $200) lubricated by DOF (@ $800). People struggle because they are trying to figure out what approach provides the greatest IMSB reliability – LN supposedly better bearing or the combined DOF fix’s supposedly better lubrication approach.

If the bearing is the problem, then the LN approach might be best. If lack of lubrication is the problem, then the DOF approach might be best. And if these two points of distinction – bearing quality and lubrication method - don’t matter much in real wprld applications, then the low cost option is the rational economic choice.

TuneRS, I can fully understand why you would not want to get involved with a discussion of competing technologies except through PM or email. Indeed, one might even consider a refusal to get involved in what will inevitably devolve into public mud-slinging as taking the 'high road.' Neverhteless, from a reading of this entire thread I do not believe that anyone has suggested that DOF is a bearing replacement - although most posters who reference the system are suggesting both a bearing replacement/upgrade AND DOF where possible - i.e., in all but the later large single bearing engines in which the bearing cannot be replaced without engine tear-down.

Frankly, I and various other posters have been not only interested in the DOF technology, but supportive of the concept. To date it would seem that the only concerns expressed (apart from, like the LN Solution, the understandable lack of real-world use in a large number of cars over a number of years) is with respect to two issues:

1. potential oil pressure loss/differing oil flow characteristics in the engine;
2. potential aeration of the oil and the effects on the A/OS and upon lubrication generally.

I and others have already opined that, as the engines are engineered to take into account significant variations in oil pressure, the small amount of oil being directed to this bearing should not have deleterious effects upon lubrication of other parts of the engine. Certainly your successful testing even in racing environments would tend to support this.

I and others have also opined that, with oil entering under pressure through a line that should not contain air, aeration should not be a problem. Nevertheless, I and others have also encouraged a test that would compare oil on comparable vehicles both with, and without DOF, after equivalent hard runs. While I suspect your technology would pass with flying colors, a test/deomonstration should go a long ways towards dispelling concerns that are clearly held by a number of prospective customers.

Surely, answers to these questions in a public setting can only benefit your company. You would not be required to attack other products as, from what I can see, your DOF is the sole product on the market that is attacking the problem from a lubrication, rather than bearing design/construction approach. It is also the only product that can be used on the later, large diameter single-row bearings - which, in spite of some suggstions to the contrary, have suffered a significant number of failures even though the engines are newer and in some cases, much newer than the earlier single-row and dual-row bearings. I think we can also safely assume that without adequate lubrication, the number and percentage of failures in those large bearings will go up with increasing mileage and the passage of time.

Is splash lubricaton of the IMS bearing through the removal of the outer seal adequate in all driving conditions? The fact that this is apparently the only recommendation made by Excellence magazine is in no way conclusive; indeed, in a magazine that relies upon advertising revenue, it is understandable that they would not support any one technology over another. I also find it difficult to believe that if the solution was that simple, Porshce would not have merely removed the outer seal in later vehicles and recommended the same in a service bulletin on cars that had suffered failures, or required a clutch replacement.

In sum, this thread has shown that there is a great deal of interest in DOF technology even though there are some questions that remain unanswered. I, for one, believe that you would be doing this group of potential customers and yourself a real service by attempting to answer them. Don't take the bait - don't engage in mud-slinging with posts from competing technologes who are obviously proceeding from a biased perspective. Do, however, take this opportunity to not only explain your technology and to extol its virtues, but to answer some legitimate questions which have already been posed.

Brad

This and other IMSB evaluations are currently being carried out by a third party. We have no affiliation with them, we only learned of the evaluation when they called us looking for test components, after they found the IMS Solution was out of stock everywhere they looked.

I made sure they received a component, though the unit I had to send to them already had 10,700 miles on it :-)

What they find will be interesting, and why they are doing the work is still both mysterious and interesting. They are NOT from the automotive world, but rather the General Aviation engine industry.

Maybe we'll have the opportunity to compare notes based on our own studies after they are all finished. I asked what they were comparing and their one word reply was "everything", but thats all they'd say.

I still made them pay for the unit, no freebies here and I charged them retail for a part that they know was used with more than 10K on it!

Jake, very interesting indeed. Do you know if they are prepared to share the results with you (or to make them public)? I am not familiar with aviation engines, but do you (or does anyone else) know if any of them use an IMS?

Brad

After watching Pedro's video....

Why would a vertical mount display of the bearing throwing oil be relevant to a horizontally mounted one? What testing was done to validate this relationship? Isn't the load at startup (when it is immersed in oil if the seal is removed) that is greatest?

Why wouldn't there be a discussion/description in the September 4th video on removing the outer seal so the oil can more easily enter the bearing? And why not just replace the bearing then?

There seems to be an acceptance at the point the video was made at continuing to use the OEM bearing yet in more recent postings that seemed to have changed.

With the DOF, where does the oil go once it gets past the intermediate bearing ball/race and hits the inner seal? Into the tube like it is said it does now? If a different route, what causes the difference? I see a port in but no port/path out is described.

How would one know on pulling the transmission that they should remove the outer seal? Or is this is even part of the DOF kit install procedure? How would they know to replace the bearing? With what bearing and why isn't that an optional part of the DOF kit?

There is the statement that "people" started reporting failures with the LN kit. Curious where the reports came from as the failure rate from any cause has been said to be less than 1/10 of 1% by LN. I've seen only one forum-posted claim and tracing it back the install was a first time install and very questionable.

The statement was made that there were hundreds of the DOF kits installed as of the posting on 9/4. Can't see why anyone would shy away from saying that when asked here. It is a far cry from a few done recently that might have been assumed.

Absolutely! Bearings are NOT happy if they are not lubricated. We've had this before at my factory - a piece of equipment is returned from rebuild. It's not lubricated by the rebuild shop. We assume it is and put it in the machine. How long do you think it lasts? :confused: Not long!

This is from the LN Engineering IMS Retrofit website:

http://986forum.com/forums/uploads01/301382641223.jpg

See that tiny slit between the IMS shaft and the IMS bearing cover? That's what the IMS Retrofit depends on to get oil bath, splash, or mist lubrication from. That's what scares me about that solution - there is not a great, reliable path for consistent lubrication. Now if you could pump in oil from inside and just let it drain out of that slit you would end up with the area between the end of the shaft and the cover filled with oil - thus flooding the bearing at all times. Both the TuneRS DOF and IMS Solution plain bearing put oil inside and drain out of this slit. I don't see why aeration or anything else would be a concern in either application.

Kirk Bristol

There seems to be an acceptance at the point the video was made at continuing to use the OEM bearing yet in more recent postings that seemed to have changed.

Personally I question whether the OEM steel bearing isn't sufficient, with proper lubrication. I just posted on Pelican data for the OEM bearing and it is actually stronger in dynamic loads than the IMS Retrofit ceramic bearing. OEM double row is unquestionably strong enough for the application (again see my Pelican post with the comparison chart). TuneRS doesn't come across as real strong in having to replace the OEM bearing if it is not worn - kind of the "if it ain't broke, don't fix it" idea. Personally, as long as I'm in there I'm going to at least install a new steel bearing.

With the DOF, where does the oil go once it gets past the intermediate bearing ball/race and hits the inner seal? Into the tube like it is said it does now? If a different route, what causes the difference? I see a port in but no port/path out is described.

See my picture in my last post and in a previous post. The oil drains through the slit between the shaft and the cover. As this is a small opening the area around the bearing will probably fill with oil and maybe even provide back pressure to the in-feed.

How would one know on pulling the transmission that they should remove the outer seal? Or is this is even part of the DOF kit install procedure? How would they know to replace the bearing? With what bearing and why isn't that an optional part of the DOF kit?

TuneRS has not focused their discussions on the bearing, but instead the lubrication kit that they offer. The kit does come with a new SKF steel single row or double row bearing. They are both RS types - which means sealed on one side, open on the other, ready to install. They also offer ceramic bearings that are significantly stronger (static and dynamic load). More details are on their eBay listing:

Porsche Intermediate Shaft Bearing Direct Oil Feed DOF Kit Single Row IMS | eBay

I am familiar now with what comes with the kit because I've called Mike and asked him a ton of questions and he has e-mailed me specs on the stock and ceramic bearings. All of this was to help me make an informed choice for myself and my cars. I've done that and last night I got my first kit from TuneRS. I think I'm going to install this one in my 2003 Carrrera 4S with a single row SKF 6204-RS steel bearing. I will see how that goes and then get a kit for my Boxster.

Kirk Bristol

Mike, I believe that a new bearing is and always has been an option on the DOF kits - except, of course, for engines with the larger single-row bearing that cannot be replaced without engine tear-down. Indeed, as I recall TuneRS had originally included a new steel bearing with the kit, only the ceramic one being an extra cost option. And Kirk, thanks for posting that photo - it certainly does make clear the limited path available for splash lubrication. I am not saying that it IS insufficient, but it at least begs the question.

Brad

What bothers me about depending on splash oil is the sprocket on the IMS shaft looks like it would act as an impeller moving oil away from the bearing.

The example from the photo posted is equivalent to the gap on the dual row IMS bearing and flange assembly. That photo is actually a quadruple row IMS Upgrade we used to do on dual row bearing IMS shafts. We used conventional bearings in the very beginning, of which there are probably a dozen or two still in service.

The LN single row IMS Retrofit kit actually has a larger gap and we actually redesigned the flange last year providing an even larger gap to allow significantly more oil to get in there along with cryogenic treatment of the single row ceramic hybrid bearing to further improve the wear characteristics of the bearing races. However marginal an increase, we found a study claiming positive benefits of the process for 52100 bearing steel.

To quantify the lubrication requirements of the IMS bearing, I had a lengthy discussion with our bearing manufacturer and the lubrication requirements for a ceramic hybrid bearing are minimal and that barely more than one drop per minute is required, so about 1/20th of a cc.

As such, I will re-iterate that the IMS is submerged in oil and there is more than adequate lubrication with an open bearing in the M96's wet sump.

Where are you getting your data from on load capacities?

I'm sorry, but our ceramic hybrid bearing can't be weaker than OEM but TuneRS's ceramic hybrid is stronger. It doesn't work that way. There is a given load capacity for a 6204 single row bearing, whether conventional or not. Just by going with a ceramic hybrid will you gain load capacity. In fact, some charts say you might loose a bit, but by all measures, a ceramic hybrid bearing is considered superior to a conventional and is a logical choice for this application.

As far as conventional bearing replacements, there already is a kit with a conventional bearing - the Pelican kit. If you want to allow engine oil to lubricate it, just pull the seal.

Kirk,
My comment was not questioning the correct lubrication of bearings but the fact that THOUSANDS of the earlier LN ceramic ball bearings are in service since 2007/8 & significantly without any reported failures. To my mind this means that the (presumably) questionable oiling from splash or otherwise is adequate for ceramic hybrids. Perhaps not so for the original steel deep groove ball bearings as fitted by Porsche.

Its only relatively recently that the "lubrication" mousetrap has been mooted as a primary cause of bearing failure - previously everything hinged on the original bearing type being at fault.

This is something we have been re-iterating for years now, particularly in the case of the 06-08 which uses a 6305 bearing that cannot be serviced without dis-assembly of the engine. Following the research of shops like Hartech and Autofarm in the UK who have been removing seals off bearings for years to allow the sump oil to lubricate the stock bearing, we have recommended doing the same.

Yes, we offer a ceramic hybrid IMS kit for the 06-08 IMS shaft, but honestly, a conventional bearing with the grease seal removed will probably be sufficient. But that said, why not put something in that is better while the engine is apart and same goes for the stock single and dual row bearings if you go through the trouble to service or change it.

If you are going to do it yourself and value your time as free, then maybe a Pelican kit that needs more frequent servicing is the logical choice for some. For others it might be a different choice. It's a free country - you can make any choice you want. However, it is our job to make sure that the information being shared is truthful and accurate, otherwise you can't make a well-informed decision.

As far as the spin on oil filter adapter, it is great to keep debris from recirculating into the engine, but more important is my recommendation of a magnetic drain plug along with frequent oil changes to allow for closer inspection of debris. Knowing there is a problem and being aware of it rather than ignoring it or even worse, not knowing, is the point of these articles and discussions.

For the record, the DOF is not to be used with any LN Engineering Retrofit Kit:

tuneRS Direct Oil Feed - Page 2 - 996 Series (Carrera, Carrera 4, Carrera 4S, Targa) - RennTech.org Forums

The 'tiny slit' can't be a serious problem if the LN folks are seeing their bearings going more than 50,000 miles with no wear.

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.....

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.

http://i83.photobucket.com/albums/j3...psaf40437b.jpg

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.

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.

Thanks Jeff for providing the answer. Presumably the thickness of the flange at the point of the center bolt is now identical to the original and hence, should not only allow appropriate torque but equivalent strength. I was not aware of this change in design since introduction and I must agree, it would appear that at the time of introduction the DOF was still something of a 'work in progress'. Whether that is still the case is uncertain, but regardless, it does stand as an argument in favour of waiting a bit longer before rushing into this new technology.

Brad

I am getting my load data for the steel bearing from SKF as I plan to use this brand in my personal car. The load data for your bearing came from your website:

"The 6204 bearing currently used in the LN Engineering IMS Retrofit has a dynamic load capacity of 2900#"

If that is not correct, then I would invite you to post static and dynamic load ratings for your IMS Retrofit bearing. But based on this information the SKF 6204 with a dynamic load rating of 3,032# certainly appears to be comparable to the IMS Retrofit, if not marginally better. More details are in the Pelican Parts thread.

Kirk Bristol

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

Our responses will be posted on Monday.

The available data strongly suggests there is not a lubrication problem AFTER one removes the IMSB seals. Unsealed bearings hardly ever fail. So it looks like we are having a grand "belt and suspenders" debate over reducing the risk of something that isn't a risk in the first place. My 2 cents for the day.

I've been out reading the technical literature on various bearing manufacturer websites concerning lubrication. The takeaway is more is not necessarily better, particularly at high speeds, and required viscosity goes down with speed. Spinning the IMS slowly after oil has replaced the grease might not be best approach for IMSB life. Looking at the lubrication requirements makes it clear that a correct application of lubrication is important. Simply squirting oil at the bearing does not appear to be a technically sound solution.

With my 60,000 mile 06 Boxster S currently with no problems i am kind off waiting for either the clutch or flywheel to give me issues and then address the IMS issue with one off the remedies mentioned,at the very least pull the seal and let engine oil lube the bearing.(definately not pulling motor and splitting cases) alough the "Solution" would be my ONLY option if i could afford it. Anyone know how long clutches or flywheels usually last,i dont track the car.
Ps: surprised to read that the DOF is already being tweeked .A year from now we will all be much better informed as to the BEST fix for this IMSB issue and the company with the most affordable,reliable and proven method will surely prosper.Good luck to all and we the consumer will be the winner!

Some food for thought, I'm not sure I would worry about the size/strength of the bearing in MY 06-08 cars. The 6305 bearing in those cars is a monster compared to the single row 6204 in MY 01-05 cars. Here are some comparative pictures I just took. In these pictures the 6305 is just a standard SKF steel bearing. The 6204 is a ceramic hybrid bearing but it's the same size as the OEM steel 6204 bearing.

http://986forum.com/forums/uploads01...1382748124.jpg


The 6204 is actually smaller overall than the inside of the outer race of the 6305!

http://986forum.com/forums/uploads01...1382748148.jpg

Kirk Bristol

Thx for the pic Kirk,Wow!! I have never seen the two bearings side by side,u are correct thats a monster in comparison.Does it also have a thicker wall? I would guess that the seals on the larger bearing are also thicker and therfore stronger which may also help in regards to oil penetration. With regards to the law suit strictly related to autos 01 thru 05 , i wonder if people with 06 thru 08 autos that in time start to have similiar IMS problems.
Will they have less problems making a claim with Porsche now that there has been a documented and proven problem.Based on how Porsche handled this issue of denial over the last 10 years or so,knowing full well that there was an legitimate concern or problem i don,t feel reallly comfortable in purchasing a DFI car with all new technology which may down the road prove to have problems that they will deny until people force them to act!
Raby has already shown pics off excessive cylinder wear on low milage units of DFI cars that werent tracked (probably heat related). Good luck.

If lubrication really is the problem, then why would bearing size even matter?

You can see in the picture that the 6305 bearing has thicker races. The width of the 6204 bearing is 14mm while the 6305 is 17mm wide (or what I believe you are calling thick). So yes, the 6305 bearing is bigger all around. It also has bigger balls... :p

Kirk Bristol

Great question...

In theory the answer could be that it takes bit longer for friction to destroy a bigger bearing just like it takes a saw a few more strokes to cut through a few more millimeters of wood. In practice, it doesn't matter unless the actual failure mechanism is related to load bearing capacity.