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.