LN Engineering Ceramic IMS Bearing Failure at 30k miles
#106
Nordschleife Master
Join Date: Nov 2008
Location: Mooresville, IN (Life Long Cheesehead)
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I'm stepping in.......I think the bearing failure is a result of another cause. I think it was installed out of alignment. Look at the threaded stem the nut goes on....do you see how distorted the end of the stem is? Was it whacked into place? I also think the rear collision shook a bunch of debris loose......stepping out with food for thought.
#107
Drifting
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An interesting bearing issue has been lost.Lets get back to fixes ?
Whatever the cause of this bearing failure - would any particular bearing type have survived better than the single row deep groove ,ceramic hybrid shown in the photographs ?
Martin speculates that a cylindrical roller bearing is the solution without having identified the cause of the problem.
Unless we know the cause of the failure ,how can anyone recommend a specific bearing type ?
The misalignment issue is new(for me and many others it seems) in the IMSB saga .
The theoretical solution is a spherical bearing ,not a roller,not a deep groove ball. A plain,spherical bearing, or a ball-type spherical bearing maybe -like a CV joint.
Why measure for misalignment ? Just fit a spherical bearing !Ducking for cover !
Whatever the cause of this bearing failure - would any particular bearing type have survived better than the single row deep groove ,ceramic hybrid shown in the photographs ?
Martin speculates that a cylindrical roller bearing is the solution without having identified the cause of the problem.
Unless we know the cause of the failure ,how can anyone recommend a specific bearing type ?
The misalignment issue is new(for me and many others it seems) in the IMSB saga .
The theoretical solution is a spherical bearing ,not a roller,not a deep groove ball. A plain,spherical bearing, or a ball-type spherical bearing maybe -like a CV joint.
Why measure for misalignment ? Just fit a spherical bearing !Ducking for cover !
#109
Former Vendor
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If misalignment exists anything that's installed into the engine will operate in less than optimum conditions. If it's misaligned, then nothing will be anything more than a band aid that sooner or later will be compromised.
This misalignment issue is not new.
This misalignment issue is not new.
#110
Rennlist Member
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"The misalignment issue is new to the IMSB saga .
The theoretical solution is a spherical bearing ,not a roller,not a deep groove ball. A plain,spherical bearing"
I don't think "the misalignment issue" is new at all - it's just that Jake Raby only recently identified it as such (I think it's safe to say he's known about it for a while). As for "the theoretical solution" of the spherical bearing, I think Jake would take issue with that description as he recently received a patent for such a bearing. Just coincidently it's called "The Solution"
The theoretical solution is a spherical bearing ,not a roller,not a deep groove ball. A plain,spherical bearing"
I don't think "the misalignment issue" is new at all - it's just that Jake Raby only recently identified it as such (I think it's safe to say he's known about it for a while). As for "the theoretical solution" of the spherical bearing, I think Jake would take issue with that description as he recently received a patent for such a bearing. Just coincidently it's called "The Solution"
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#112
Rennlist Member
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"Nope, I just started talking about it."
That's exactly what I meant when I said
"I don't think "the misalignment issue" is new at all - it's just that Jake Raby only recently identified it as such (I think it's safe to say he's known about it for a while)"
That's exactly what I meant when I said
"I don't think "the misalignment issue" is new at all - it's just that Jake Raby only recently identified it as such (I think it's safe to say he's known about it for a while)"
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#113
Instructor
Thread Starter
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I just ran across notes from my mechanic while the old engine was still in the car. He read out the camshaft deviation at 1.69 degrees on bank 1 and 0.88 degree on bank 2, which are well within Porsche's spec of 6 degrees. He said that this meant that the IMS bearing was not installed crooked; it it were, the deviations would be a lot worse.
#114
Drifting
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Which leaves a manufacturing defect (like adverse cumulative tolerances) as the potential cause of shaft or bearing misalignment ?
If this is correct, changing to a roller bearing will not be a long term solution.
Spherical bearing maybe?
If this is correct, changing to a roller bearing will not be a long term solution.
Spherical bearing maybe?
#115
Race Director
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I propose an immediate adoption of Michell/Kingsbury fluid bearing retrofits. In addition to the bearing itself, it will be necessary to tow a compressor/gas generator to supply the necessary air pressure and volume, but otherwise this is foolproof. Note that some modification to PCV will be required to discharge the extra few hundred CFM of high-pressure air. Probably the motorsport AOS will work.
Last edited by 5CHN3LL; 04-23-2015 at 08:46 PM.
#116
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lol
I'm beginning to come around and see some of the logic in Jakes' thinking. I had no idea the engine cases could be machined with such inaccuracies. Hard to believe, but if true, explains so much about the unpredictability of these failures.
Still subscribed
- begs the question: can this machined misalignment be corrected?
That is my next question.
regarding "shock" and its' effects, while I may struggle translating it to a vehicular accident, this is where I live:
I'm beginning to come around and see some of the logic in Jakes' thinking. I had no idea the engine cases could be machined with such inaccuracies. Hard to believe, but if true, explains so much about the unpredictability of these failures.
Still subscribed
- begs the question: can this machined misalignment be corrected?
That is my next question.
regarding "shock" and its' effects, while I may struggle translating it to a vehicular accident, this is where I live:
Last edited by TSMacNeil; 04-23-2015 at 10:53 PM.
#117
Former Vendor
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I just ran across notes from my mechanic while the old engine was still in the car. He read out the camshaft deviation at 1.69 degrees on bank 1 and 0.88 degree on bank 2, which are well within Porsche's spec of 6 degrees. He said that this meant that the IMS bearing was not installed crooked; it it were, the deviations would be a lot worse.
It takes considerable IMSB wear to show up as a cam deviation as well, and even then it will ONLY impact bank 1, as the end of the IMS thats supported by the IMSB only drives bank 1. I typically find cam deviations that are measurable well into Stage 3 IMSB failure; but, not before.
I do not agree with his statement, or theory at all.
The misalignment will not show cam deviations, because it is both very slight and also because the cam timing procedure and hydraulic chain tensioner will mask this.
The only way to find this slight misalignment (measured in thousandths of an inch") is by using a precision device that measures three different dimensions simultaneously giving an actual value.
A slight misalignment is HUGE to the IMSB as it places loads in a localized region of the inner race.
#120
Race Director
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OK, guys, not to steal any of the thunder from other inventors here, but I decided to tackle this one.
Took me nearly 10 minutes to design a frictionless magnetic flux bearing. No more oiling systems needed, no ball, roller, or other contact-type bearings, and you can whack the car from the rear, front, side all you want and it will remain perfectly centered.
I'm going to name it The Ultimate Solution. Is that name taken? I expect retail price to be approx. $19.95 if I can get the right Chinese fabricator.
You're welcome.
.
Took me nearly 10 minutes to design a frictionless magnetic flux bearing. No more oiling systems needed, no ball, roller, or other contact-type bearings, and you can whack the car from the rear, front, side all you want and it will remain perfectly centered.
I'm going to name it The Ultimate Solution. Is that name taken? I expect retail price to be approx. $19.95 if I can get the right Chinese fabricator.
You're welcome.
.
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Zuffwerks (11-10-2022)