IMS solution,or Pedro's DOF

[flmont]

who was first and who is correct,

[elgyqc]

Yes... but than again, no... or maybe, maybe...
Here we go again?

[Geof3]

We need a popcorn emoji/smiley

[paulofto]

Boy Oh Boy!

[elgyqc]

Originally Posted by Geof3

We need a popcorn emoji/smiley

Right on!

But seriously, as a Boxster owner who has been wrestling with the IMS question since I bought my first Boxster I would suggest looking at other products... why should I be the only one who changes his mind weekly after reading a different article or thread? Personally I am leaning towards the FVD but considered the EPS roller bearing kit, if I do anything. Since both my cars should be dual row bearings I will likely not touch the green one which has less than 90K miles and a good clutch. The blue Boxster with 115K miles and a clutch that feels a bit tired is a candidate for a disassembly and inspection.

The original poster does not mention the year of his Boxster... if I had a 2001 or later I would definitely perhaps maybe change the IMSB right away.

[kk2002s]

Let the games begin

My bet is on Mobil-1 0-40

Actually it a decent question as they are different solutions.
I think they are both oil feed but I believe Pedro's still uses a bearing while the IMS solution is a non-bearing, same as the front (For a Boxster) of the IMS

I also believe the IMS Solution is touted as the 'Final solution'

[paulofto]

Originally Posted by kk2002s

I also believe the IMS Solution is touted as the 'Final solution'

Yikes, never use that term when talking about anything from Germany

[PaulE]

I think LN refers to the IMS Solution as a Permanent Solution. Final Solution has a bad historical reference. What I find interesting is that RND is another Charles Navarro company and they offer the RND RS Cylindrical Roller IMS bearing retrofit, which is what the use in their RND rebuilt M96 and M97 engines. The IMS Solution has a journal bearing, just like the bearings used on the crankshaft and rod big ends in the rest of the engine, along with the front bearing in the IMS. Why Porsche ever thought using a grease filled sealed bearing (lubricated for life, ha ha) was a good idea, along with a 15,000 mile oil change interval by the way, will always be a mystery to me.

For my rebuild after a ceramic IMSB failure, I went with the IMS Solution. For me it is the final solution, because if the engine fails again I will be done with this car!

[JFP in PA]

Originally Posted by PaulE

I think LN refers to the IMS Solution as a Permanent Solution. Final Solution has a bad historical reference. What I find interesting is that RND is another Charles Navarro company and they offer the RND RS Cylindrical Roller IMS bearing retrofit, which is what the use in their RND rebuilt M96 and M97 engines. The IMS Solution has a journal bearing, just like the bearings used on the crankshaft and rod big ends in the rest of the engine, along with the front bearing in the IMS. Why Porsche ever thought using a grease filled sealed bearing (lubricated for life, ha ha) was a good idea, along with a 15,000 mile oil change interval by the way, will always be a mystery to me.

For my rebuild after a ceramic IMSB failure, I went with the IMS Solution. For me it is the final solution, because if the engine fails again I will be done with this car!

The two products are based on different technical premise's: The IMS Solution is based upon the long proven bearing design used in the air cooled turbo engines, the DOF is based upon the questionable premise that "it is not the bearing, it is the lack of lubrication". The reason this is questionable is that if it really was the lack of lubrication, the dual row bearing with twice the bearing surface contact area should fail more frequently than the single row, "due to a lack of lubrication", which is exactly counter to reality.....

[Homeoboxter]

Originally Posted by JFP in PA

The two products are based on different technical premise's: The IMS Solution is based upon the long proven bearing design used in the air cooled turbo engines, the DOF is based upon the questionable premise that "it is not the bearing, it is the lack of lubrication". The reason this is questionable is that if it really was the lack of lubrication, the dual row bearing with twice the bearing surface contact area should fail more frequently than the single row, "due to a lack of lubrication", which is exactly counter to reality.....

It’s actually the opposite, since the bearing wear is twice as fast in the single row because of the double load compared to the dual row. So the single row starts pitting much sooner. DOF would make sense if the failure was the result of lack of lubrication. But that’s not the case in a bearing that’s swimming in oil all the time.

[JFP in PA]

Originally Posted by Homeoboxter

It’s actually the opposite, since the bearing wear is twice as fast in the single row because of the double load compared to the dual row. So the single row starts pitting much sooner. DOF would make sense if the failure was the result of lack of lubrication. But that’s not the case in a bearing that’s swimming in oil all the time.

The theory on the DOF is the lack of lubrication causes heat build up, leading to galling and failure. As the dual row has twice the contact area, the heat build up in the bearing should be both faster and to a higher temp, which should be leading to its failure sooner than the single row. But that is not what happens in the real world, were single rows fail at a rate near ten times that of dual rows.

[Homeoboxter]

Originally Posted by JFP in PA

The theory on the DOF is the lack of lubrication causes heat build up, leading to galling and failure. As the dual row has twice the contact area, the heat build up in the bearing should be both faster and to a higher temp, which should be leading to its failure sooner than the single row. But that is not what happens in the real world, were single rows fail at a rate near ten times that of dual rows.

I don`t think the contact area really matters here. The axial force on each ball is double in a single-row bearing as compared to a dual-row. The contact surface from the bearing ball`s point of view is identical in both single-row and dual-row. Heat dissipation is similar too, as it`s like putting two bearings next to each other. What is different, is the load. If the bearing was running completely dry, the dual row would still last longer.

[jaykay]

Originally Posted by JFP in PA

The theory on the DOF is the lack of lubrication causes heat build up, leading to galling and failure. As the dual row has twice the contact area, the heat build up in the bearing should be both faster and to a higher temp, which should be leading to its failure sooner than the single row. But that is not what happens in the real world, were single rows fail at a rate near ten times that of dual rows.

Yes all good thoughts but I am not sure a dual row would produce more heat, or critical heat levels because there are more points of contact. Friction is driven by “normal” loading of one element against another and in the case of a dual row one can argue the loading is split between two bearing assemblies. Normal loads are lower at each yielding lower friction forces perhaps below critical levels.

Having said all of this I am of the opinion that poor brearing design is a main factor and that no amount of lubrication in a rolling element bearing will circumvent an overload condition

[Javi Cooper]

Originally Posted by Homeoboxter

It’s actually the opposite, since the bearing wear is twice as fast in the single row because of the double load compared to the dual row. So the single row starts pitting much sooner. DOF would make sense if the failure was the result of lack of lubrication. But that’s not the case in a bearing that’s swimming in oil all the time.

But that's actually the reasoning behind the DOF; the bearing, even though it's submerged in oil at rest, is NOT submerged in oil at all when the engine is running, contrary to popular belief. Here's a visual explanation from Pedro:

https://www.youtube.com/watch?v=qj06dqBk0to

[SC-986]

Certainly not an expert here and all I can offer is my own personal experience. I purchased my ‘04 S about 1 1/2 years ago. One of the selling points was that the IMSB was upgraded in 2014 at 87,000 miles. The car now has 114,000 miles on the odometer. The DOF option was used and at the time of purchase I hadn’t researched the major differences between the DOF and LN’s offerings.

Fast forward to today and my ‘02 base at 168,000 mi. recently threw a cam deviation code. It is in the shop for further diagnosis and so I have spent a good bit of time researching the different IMSB upgrade options in the event that is the problem.

It seems the naysayers of the DOF system claim that where the oil is drawn from the engine to lubricate the IMSB is problematic in that it could be contaminated with debris or cause oil pressure problems on bank 2.

To date with nearly 30,000 mi. on the DOF system I have not experienced any oil pressure issues and I drive it pretty hard through the twisties of the Blue Ridge Mtns.
The drain plug magnet and filter do not have any ferrous material on or in them.

Most people will not write about a thing if it is working as designed, they only write about it when it fails. In my research I ran across (3) occurrences where LN’s ceramic retrofit bearing failed between 30,000 - 40,000 miles resulting in catastrophic engine failure. I found (1) occurrence of a DOF system concern where there was some valve train noise on bank 2 and when the oil feed was disconnected the noise went away - no failures per se.

On my ‘02 base if it requires an IMSB replacement, because of the high mileage, I will probably go with the DOF option. The IMS Solution is the gold standard and if the car had lower mileage I would opt for that. With the DOF system I can take the 1000.00 saved over the Solution and apply it to future engine repairs.

[Homeoboxter]

Originally Posted by Javi Cooper

But that's actually the reasoning behind the DOF; the bearing, even though it's submerged in oil at rest, is NOT submerged in oil at all when the engine is running, contrary to popular belief. Here's a visual explanation from Pedro:

https://www.youtube.com/watch?v=qj06dqBk0to

Yeah, I came across this video. Still, I don`t think it justifies the need for DOF. The IMS is submerged almost all the way to the top of the shaft when your level is at the max sign, and is submerged around half way up when it`s at the min level. So, the inner ring (that is fixed) is always submerged in oil that will carry excessive amount of oil onto the balls and the outer ring. Centrifugal force has nothing to do with this because the inner ring is not spinning. Ball bearings do not require DOF. There are motorcycle engines with ball bearings operating at much higher rpm and temperature that an IMSB and they are totally fine with submerged or splashed oil lubrication or even oil mist in 2-stroke engines. But you don`t have to go that far, look at the ball bearings in your transmission, they are lubricated by splashing oil, and they don`t fall apart, even if the input shaft is spinning at much higher rpm than the IMSB.

[B6T]

Originally Posted by PaulE

Why Porsche ever thought using a grease filled sealed bearing (lubricated for life, ha ha) was a good idea, along with a 15,000 mile oil change interval by the way, will always be a mystery to me.

This is my interpretation of it...

Option A:
Provide a means of supplying lubricating oil to the plain bearing arrangement at the back of the engine by increasing the complexity/weight of the engine case casting, the machining cost to gun-drill all the oil passages, and the potential failures related to poor machining/casting from this additional oil passage, in addition to the more complicated/costly bearing components. RND was probably the second group to evaluate the oil-fed plain bearing, Porsche being the first.

Or...

Option B:
Install a sealed bearing that doesn't require lubrication.


People seem to think that Porsche doesn't know what they're doing. At the design stage for this engine, all relevant data would have suggested that the sealed 6204 bearing was the best option based on reliability and cost (cost being the most important factor in automotive design).

[particlewave]

Twice baked potato gets my vote.

[Burg Boxster]

Originally Posted by particlewave

Twice baked potato gets my vote.

Vehemently disagree, PW... rice pilaf pairs much better

[particlewave]

Originally Posted by Burg Boxster

Vehemently disagree, PW... rice pilaf pairs much better

That's BS and you know it. You have no data to back that up.