IMS "Solution" plain, oil-fed bearing

[Coles]

Hi

I am a new owner of a 2003 Boxster S and have had a look on the web at LN Engineering's IMS Solution (as opposed to their IMS Retrofit ceramic bearing). The IMS Solution is a plain bearing with its own dedicated pressured oil supply (ie no balls,rollers or cages to disintegrate).
I have enquired of Autofarm if they are aware of this IMS bearing and they are making enquiries of their supplier for LN bearings, but their seem to be problems getting them (the plain bearing) from the States. They are pursuing it nevertheless. My thought is to replace the IMS bearing when the clutch is done (current one on 76k miles but OK at the moment). Has anyone heard of this plain bearing system - any thoughts? There is a good video showing installation of the system at the web site IMS solution.

Brian Coles

 

[Richard_Hamilton]

Welcome Brian! I believe Revolution Porsche were the first to fit one in the UK. See here: http://www.revolution-porsche.co.uk/the-ims-solution/

 

[Coles]

Thanks Richard! I emailed LN Engineering yesterday to ask if any UK companies could fit their "Solution" and got a reply from Jake Raby himself who said that so far no UK companies were willing to travel to the USA undertake the required training and assessment which they require. He must have overlooked Revolution! It seems to me that if you are going to have an upgrade this is the best engineered so I will probably go to Revolution for it. I do love my new Boxster but I have these niggling worries at the back of my mind! I have just sold my BMW R1200 GS Adventure to move to Porsche. The bikes are great but you do get some grumbles about reliability on the BMW Forums as well! Brian Coles

 

[Boxstercol]

Anyone know the approx cost of this to be fitted?

 

[Coles]

I have emailed Revolution to ask for costs and will post this when I hear back. Brian

 

[Coles]

Russ at Revolution Porsche West Yorks has quoted me an approximate price of £1400 plus VAT but he would have to import the kit from the States so price would reflect currency variations, duty etc. Currently it seems the UK importer/distributor has not been able to negotiate a deal with LN and they have also set a requirement for fitters to attend their course in the states before they are certified. Revolution can import the kits direct but without the course there would be no warranty on the parts. Revolution will not be attending the course but are confident that they have the experience and skill to fit the bearing without the training course, and customers seem willing to accept that. Revolution do feel that this bearing is the best. When I get my clutch done I will probably get this bearing fitted as it seems bulletproof looking at the design. But maybe any engineers out there might disagree?

 

[Motorhead]

Brian, Being a (retired) mechanical engineer, I'm not sure that I'm better placed than anyone else to offer you advice. However, although LN Engineering appear to have an excellent - and established - track record with their IMS Retrofit product, it's not clear to me how recent or well-developed is their IMS Solution product which you favour. By replacing the troublesome ball bearing with a pressure-fed plain bearing, it does look to be a very well-engineered and promising solution to the IMS problem, but you could end up being a guinea pig for the product. Personally, I would be more inclined to opt for the IMS Retrofit which is well tried and tested and will carry some sort of warranty if fitted by an approved installer. Unless, of course, LN Engineering/Revolution Porsche can convince you otherwise. Jeff

 

[Coles]

Thanks Jeff I believe the plain bearing has been developed and tested over several years (read that somewhere) but I will give it all serious thought before I decide. Cheers Brian

 

[howe]

Surely Porsche would have considered a plain bearing solution. The thing that would concern me is that all plain bearing housings are line bored e.g. crank and camshaft. How would you expect that a cantilevered stub would have precise alignment? A deep groove ball, will tolerate more misalignment and also IMS shaft deflection and much better w.r.t radial load. If I ever do mine it will be with a ball bearing again. Howe Retired Mech Eng

 

[Coles]

Thanks for that Howe. I am not an engineer although I like all mechanical stuff, eg cars, motorbikes, aircraft ships etc. I was hoping to get some debate on this subject since it seems to be the cause of much concern to 986/7 owners (including me). My 2003 Boxster S has done 77000 miles and I do wonder if the IMS bearing might go soon, or may never go.My local Porsche Centre and a couple of local Porsche specialists say it is very rare and not to worry about it and just enjoy the car. But there was a class action in the States and Porsche also seem to have replaced engines in a number of cases (how many?). The problem seems to be caused by a lack of lubrication of the original bearing, so the idea of a pumped, filtered oil supply direct to the bearing seems to be sensible. Two aftermarket systems seem to offer this: The LN plain bearing "Solution" and the "Eternal" bearing which is a caged roller bearing said to be 5 times stronger than ball bearings. The LN ceramic ball bearing "retrofit" does not have pumped lubrication but seems to rely of splash lubrication from the engine "sump". I am not sure, but I think the other end of the IMS is a plain bearing (that never fails)? Is a plain bearing unlikely to break up at all (and unlikely to ever let the IMS flap around letting the timing chain jump?) Is a roller bearing less likely to break up than a ball bearing? So which of these options/combinations is best? and would not any type of bearing last longer with a pumped filtered oil supply? Porsche sealed grease lube'd steel ball bearings Ceramic ball bearings Steel roller bearings plain bearings pumped and filtered oil feed splash oil feed I am not sure I understand the problems you mentioned about the plain bearing but perhaps you could expand a bit on that. I love my Boxster and think that Porsche are great engineers, but maybe they made a mistake in the original IMS design? They seem to have eliminated it from 2009 onwards models. Given the worries many of us have about the IMS bearing, it would be good to hear from owners what they think. And how many have 986/7s with the original bearing at over 100k miles? Thanks again Brian

 

[Motorhead]

Brian, If you read the sections on Lubrication and Roller Bearings on LN Engineering's website ( http://imsretrofit.com/ ), I think it will answer some of your questions on choice of bearing (ball rather than roller bearing) and lubrication (splash versus forced, etc.). It is true that one end of the IMS is carried in a plain bearing and it does seem puzzling as to why Porsche chose to adopt the method they did, but they will have had their reasons. To me, immersing a sealed grease-filled ball bearing in engine oil strikes me as a strange approach if you're seeking long-term durability. Returning to the point I made in my earlier post, from what I've read it does appear that the LN IMS Solution product has only just become available to the market (late 2013?) and as such is not as well tried and tested as their IMS Retrofit product. The point, I think, Howe was making is one of plain bearing alignment or - rather potential misalignment - with the IMS Solution since the two bearings are not machined simultaneously as would be the case in production. Potentially this could lead to premature bearing wear and failure. Just my tuppence worth really..! Hope you manage to reach a decision. Jeff

 

[Coles]

Thanks Jeff I hadn't seen those web pages before and they set out the arguments very well. Also I now understand about the simultaneous boring of both ends of the crankcaes to centre both plain bearings accurately. I guess LN do not see this as a problem? Jake Raby emailed me to say that an IMS solution had been installed in the UK early in 2013. Nevertheless, still relatively new. The website also talks about single and double row retrofit bearings and a retrofit plus single row bearing(stronger than the basic retrofit) which has a 75000 mile replacement interval. Maybe the plus is the one to go for. Thanks again Brian

 

[howe]

Hi Brian, My Boxster 2001 has done 88,000 klm and my insurance is simple. Change the oil every 5000klm, remove, inspect, replace the oil filter. Listen to the engine when idling every time you use it, get familiar with the sound. Ball bearings start to make noises well before they are about to fail. You would have to be tone deaf not to hear it. Last but not least if the engine has ever been over heated in its life expect the bearing seals to be shot completely. regards Howe

 

[Coles]

Thanks Howe I shall listen out for any unusual engine noises as you suggest plus frequent oil changes and examination of the oil filter. But when the clutch needs to be replaced I shall probably have the bearing replaced at the same time. I believe "planned maintenance" is the best strategy when a car is 10 years old or more. I have already had a new water pump and drive belt fitted anticipating possible failure and may also get the oil/air separator replaced too. It's the sort of car that one wants to keep in top condition and to feel confident for some long distance travel. Thanks again. Brian

 

[Coles]

Just had oil and filter change at OPC Portsmouth and took the old filter home to check for metal debris and pleased to find nothing at all. That makes me feel a whole lot happier. I shall replace oil and filter every 6k miles so hope to keep IMS bearing problems at bay.

 

[Coles]

Just been reading the 986 Forum discussion on the IMS Solution which has some intense debate between Jake Raby, who designed and manufactures the "Solution" and various others who question it. It covers a lot of issues and Jake seems to defend the engineering principles, design and testing very strongly. You can find the discussion at: http://986forum.com/forums/general-discussions/43114-yet-another-ims-solution-3.html I've also had a look at some websites on ball vs roller vs plain and there is much more to it than I realised. Brian