A Different IMS question - Experts Weigh In?

Guys, Im a new-ish owner of a 2002 911 cab. Found it with 21k miles on it in June, now has almost 25k on it. I read up A LOT on the IMS issue and options to prevent/repair/replace, etc. LN bearing made sense to me until.... Talking with a very good friend of mine (known him all his life) who owns a race team and shop, and I was discussing what he would charge to do the retrofit, and he claimed to me that there was NO WAY that he would ever put a ceramic bearing in an engine. He went on to discuss the vibration requirements and characteristics and how ceramic bearings werent right for that application, etc. Problem is, I trust him, and he knows what he is talking about. He is co founder, owner, and technical director of a shop that campaigns cars at the professional level (3 cars in the continental tire series, 1 in the Grand Am GT series), and 95% of their work is done on race cars for pro drivers and privateers. They focus mainly on BMW, Porsche, and Audi. Prior to opening the shop, he worked on cars in several IMSA series, ALMS, and also on Target Chip Ganassi IndyCar teams. So he is fairly knowledgeable and experienced. Not trying to start a flame war, but was wondering if anyone had any data or mechanical engineering background that can say why a ceramic hybrid bearing is or is not a good application? Thanks!!

Thats funny. If he races in Grand Am he has raced against M96 powered Boxsters and 996s that have ran ceramic IMS bearings. NEVER had one of those fail on the track. Not once, not ever. If you don't trust a ceramic bearing, just install the IMS Solution and omit the ball bearing wear components completely. Ask a dozen different "experts" these questions and you'll get a dozen different answers. I've utilized 282 Ceramic hybrid LN IMSB retrofits (serialized) and we have NEVER had one fail. Those range in applications from little old lady drivers to full blown PCA/ SCCA and Grand Am series race cars. Those are all over the planet, not just here in the USA. I installed the very first LN IMSB and its still alive, hasn't been changed and has hardly been serviced on purpose.

Mr Raby, I appreciate your response and respect your opinion. However, Im trying to understand why you ended up with a ceramic hybrid bearing? Im trying to understand, as he was pretty adamant about ceramic hybrids being a bad choice for engine internals. However, we were in the paddock at Road America and didn't get to go into details, and he has been on the road ever since, so I haven't been able to connect to follow up. Understand, Im not knocking any of your options, Im just trying to understand better. Thanks!

Everyone has a different opinion. Some of us have over 10,000 installs of products and have proven ourselves. Who is he and how many Porsche engine problems has he solved?

I wonder if your friend understands how the M96 IMSB bearing is designed... It sounds like his issue is more with the material than with the bearing design. If you compare ceramic to metal in a bearing application, you'll see that ceramic will provide better wear performance. It's a harder material than metal. It offers improved performance when wearing against ceramic or metal. It offers greater wettability and is superior from a tribology standpoint. The only downside of ceramic that I can see compared to metal is that ceramic is more brittle than metal and can fracture under some circumstances. Some ceramics are more susceptible to fracture than others. The risk of ceramic fracture can be mitigated by bearing design. In a roller bearing application, it should be a very, very low risk. Could it be that your friend is worried about ceramic fracture due to vibration? That's what it sounds like to me...

There is a big difference between a ceramic bearing and a HYBRID ceramic bearing. That might be the crux of the opinion difference.

Rgrove, Your friend may be misunderstanding as to how "internal" the IMS bearing is. The orginal bearing was supposed to be in an oil free environment (the IMS tube). That's why the original came with a sealed bearing with "permanent" grease. Unfortunately, the best laid plans usually jump up and bite you in the a** There are internal engine parts (rod bearings, pistons/rings etc) and there are "internal" engine parts like the IMS bearing that were meant to perform a function of the engine while not being part of the traditional rotation process. At least that is how I see it.............. and I have a LN bearing in my car.

If your friend has always dealt with GT3 motors, he's the wrong person to be asking. Just sayin...

Based on my anecdotal discussions with a career Timken engineer and various GE Aircraft Engine engineers, their consensus is (1) the choice between ceramic vs. steel bearings depends entirely on the application, but (2) ceramic generally offers superior wear characteristics with less heat build-up compared to steel. When I explained the Porsche IMS application to them (disclosure: I am not a trained engineer), they thought ceramic to be a very good choice, but were surprised Porsche persisted so long with an inadequate lubrication system design for the IMSB. relinuca

Thanks everybody for the responses. A little about his background: shop has been in business for over 12 years, 95% of the cars they do are track car builds, mostly porsche and BMW, and has been bulk of their business for years. They have a lot of experience with many of the variants of the 911, the 996 included. They also have a satellite shop to do the tuning/prep for an active road course. He was very familiar with the IMSB design and reported issues, although he said that he didnt agree that the issue was as pervasive as the internet hype. I asked his opinion about using a ceramic bearing upgrade, and that was the origin of the response. perry and relinuca, thank you, that is the type of response i was hoping to get; someone who had another opinion/source/fact that indicated that the hybrid ceramic was good for the application. Either that or maybe thought Mr Raby would chime in as to why he chose that type of bearing vs just "everyone is doing it..." Just looking for a different perspective; reality is Ill likely end up doing the LN retrofit just to be safe(r). Thanks! Ron

Actually, I didn't. My first IMSB invention was the IMS Solution plain bearing design. I assisted in the development of the ceramic hybrid IMS Retrofit bearing offered by LN from day one as well. The IMS Solution would take years to perfect, and we knew it would, but in the mean time there was an immediate need for a retrofit bearing that was better than factory, to save engines immediately. This is why the LN ceramic hybrid bearing was developed and it has served its purpose with over ten thousand units in service worldwide. In a perfect world the IMS Solution would have been available a decade ago; however the product was not ready and on top of that the market also wasn't ready for it. It ended up taking us years to work through the 7 generations of development to bring the IMS Solution to market. You can read all about it in Excellence Magazine's December 2013 issue. The article was 3,000 words based on what the writer told me and their interview with Charles and I was exhausting, to say the least. I personally can't wait to read it myself.