First time I heard of this theory... IMS

[JFP in PA]

Originally Posted by Nine8Six

There is only two things that can horribly go wrong in a high speed or heavy shaft/bearing design really. First is (as you've indicated) the TIR or runout, or both for this matter. Second is rotational torque vibration & noise caused by improper damping (as you've also indicated, the chainS, and which I also personally suspect; critical speeds). Lubrication is also a failure type however in a shaft application rotating >5000RPM the first two are far more subject to cause catastrophic failures way-long before, lubrication or not.

The good news is the two main issues above are easily detectable using modern vibro acoustic technologies. My advice for the key players in the IMS business would be to develop a tool that is capable of sensing and therefore take actions based on acquired data from healthy and failing engines. Same techniques used in the aerospace and other transport/military industries, whose those actually are 'real-time'. Basically "staring at the internals" in engineering terms.

You said "there is little left to analyze". You are getting this wrong, this needs to be carried out before the failure thus 'preventing it'. Its called predictive maintenance AKA "Solution".

Sending ppl out of fear to change their perfectly fine bearings to me sounds a bit primitive given the vast and widely available condition monitoring kits (high end sensors) and training offered commercially these days e.g. Mobius, Siemens, I pass so many others.

Some who aren't familiar with VA technology will tell you a miniature car engine is a noisy environment (LOLOL), by all means, please ignore these twats; the tech is used in both turbofan & turbojet engines and +50 tons machinery motors/shafts (e.g. ships, energy/nuclear facilities, etc).

Time to modernize a tad guys (if you really care about these Porsche cars anyway).

my 0.2

Some time back, an engineer with a background in vibration analysis tried to deploy what appeared to be a very sophisticated technique and equipment to do exactly that. Unfortunately, his efforts went no where due primarily to interference vibration signals from other sources in the engine. Google it, it has already been tried and discarded.

As for "sending people out of fear" to do anything, well that is more of an opinion than a fact. If I never installed another retrofit kit in one of these engines, it would not denigrate my business or income one iota. When people ask questions, we simply try to offer the best information as we know it; what they do with that information, or how they internalize it, is strictly their business. The simple facts are that while a large number of owners of M96/97 engines will never have a problem, others will not be so lucky. The percentage failure rates are documented and in the public domain. If you choose to take preventative action, alternatives are available. If you choose not to, that is your business. No one is hard selling anything.

[356Guy]

We use VA in all sorts of industrial electrical motor driven rotating equipment but I've not seen it used in IC engines. There are a number of reasons why not. Perhaps a prox probe on the shaft would work if somebody could figure out how to install one. I'm sure smarter people than me are on it. As far as predictive technology goes there is of course oil analysis and the IMS Guardian (is it still available?) although I can't say how well that works. I may end up using oil sampling and filter inspections myself. It can be done cheaply.

[Nine8Six]

Originally Posted by JFP in PA

Some time back, an engineer with a background in vibration analysis tried to deploy what appeared to be a very sophisticated technique and equipment to do exactly that. Unfortunately, his efforts went no where due primarily to interference vibration signals from other sources in the engine. Google it, it has already been tried and discarded.

IC engine, rotary machinery, source doesn't matter or perhaps VA is misunderstood here. Aquisition would come from the horizontal, vertical and axial planes near the shaft/bearing (not from an object particularly e.g IC engine). Vibrations are 'freq' (in words) and can easily be filtered out if somehow seen as 'interference' by your equipment/engineer. In fact the more you have the better really. Seriously I'd just call your local Siemens rep and get them to help as one of their Eng Dept is doing this all day long (yes, on cars too, google it). They offer completely free training shall you decide to use their technologies (as in, you could do it yourself afterward bud).

Please Try, what can you loose.

Originally Posted by 356Guy

As far as predictive technology goes there is of course oil analysis and the IMS Guardian (is it still available?) although I can't say how well that works.

Predictive: That is exactly what I am talking about and I don't see why not this guardian thing wouldn't work (if I've understood its concept correctly). Actually a brilliant idea and I couldn't recommend it more. Certainly a better technique than just wacking out perfectly fine bearings.

OT. Can someone let me know why my Porsche dealer categorically refuses (even if I pay) to periodically replace my bearing? They strongly recommend me NOT to do it. Would it be because it'd be seen an acknowledgement to the class action in a way? Are your P dealers fine with it in the USA?

Don't believe me? just call the dealership here in Shanghai (although this was back in 2008/09)

[Nine8Six]

5800 Granite Parkway
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[JFP in PA]

Originally Posted by Nine8Six

Please Try, what can you loose.



OT. Can someone let me know why my Porsche dealer categorically refuses (even if I pay) to periodically replace my bearing? They strongly recommend me NOT to do it. Would it be because it'd be seen an acknowledgement to the class action in a way? Are your P dealers fine with it in the USA?

What can I lose? Simple: time and money. Multiple fixes already exist for the problem, and I am not in the business of re-engineering Porsche's problems. As previously mentioned, and experienced engineer in this field could not make it work, even with help from a university.

Porsche very quietly released a memo to their dealer network years ago stating that in their "official" opinion, it was not possible to replace the IMS bearing without taking the engine apart. This gave the dealers an out, both not to get involved in retrofits, and to void warranties on engines that had one done. So while some dealers actually sent techs to Jake's IMS class and quietly did do retrofits, most dealers stayed with the factory line" It cannot be done."

Another point is Porsche's parts network; they only sell complete replacement IMS shafts with the bearing already in them, they have never offered the bearing as a separate part.

[Nine8Six]

Originally Posted by JFP in PA

What can I lose? Simple: time and money.

Time & money: I'd rather spend this on cocaine and prostitutes, well, if I had any of that time OR money to spend at the first place anyway

Originally Posted by JFP in PA

Porsche very quietly released a memo to their dealer network years ago stating that in their "official" opinion, it was not possible to replace the IMS bearing without taking the engine apart. This gave the dealers an out, both not to get involved in retrofits, and to void warranties on engines that had one done. So while some dealers actually sent techs to Jake's IMS class and quietly did do retrofits, most dealers stayed with the factory line" It cannot be done."

Another point is Porsche's parts network; they only sell complete replacement IMS shafts with the bearing already in them, they have never offered the bearing as a separate part.

I c, thanks for the explanation. Sux they don't really. I was forced yo learn how to live and enjoy with the risk