Pedros Techno DOF IMS fix?

[Kirk]

Originally Posted by southernstar

I gather from your post that you have an engineering background - do you, or any of the other engineers that were present, have any concerns about aeration of the oil with DOF? Perhaps you can also chime on in the criticism that the oil in the DOF is unfiltered. That criticism seems to suggest that the oil is in a closed loop and will never pass through the filter. Although the oil does not exit directly from the filter, does it not pass through the filter as it cycles through the engine, just like the rest of the engine oil that is used to lubricate other components? Just interested in the bona fides of some of the criticisms that have been levelled at DOF.

Yes, I have an MS from Georgia Tech 1994. MBA from California State University 2011. I am also a certified Project Management Professional (PMP). I am not a bearing engineer and I have never played one on TV.

No, I do not see how aeration of the oil would be a problem. The oil flow is at system pressures (~30 - 60 psi) out of a very small hole. These are more like garden hose pressures rather than what you'd see from a pressure washer. The cavity where the bearing is held and the oil is sprayed is small with little chance for air entry. The oil will squirt in, the bearing will sling it around, and any excess oil will drain out the slit between the IMS shaft and cover. This isn't some crazy condition where we are just willy nilly spraying profuse amounts of oil around the engine sump. It's also not the "pressure washing" of the bearing that Charles Navarro described. It's a small amount of oil being sprayed into a small space. You know many Porsche engines have oil squirters that spray oil on the back of the pistons for cooling. I've never heard that aeration is specifically an issue with that either.

Honestly TuneRS already weighed in on where their oil comes from and even provided a diagram (it may be in the Pelican Parts discussion). The oil is filtered and cooled before it goes to the DOF.

On the other hand, any oil that the IMS Retrofit would be lubricated with through splash or oil bath lubrication would be oil from the sump and that oil has not been directly, immediately filtered. It is possible that there may be some contaminants in the sump, but generally contaminants will get pulled into and captured in the oil filter. We have to remember that as the engine is running the oil pumps are pumping and circulating oil through the filter over and over and over and over and over and over and over and over and over and over and over and over and over again... I think you get the point. To say that the oil going to the DOF is unfiltered is just silliness IMHO.

Kirk

[Jamesp]

I've been following the IMS discussions and mostly keeping quiet and taking data as I'm the new guy here, and to paraphrase one individual, "you can learn an awful lot just by listening". I think that premature AOS failure due to DOF oil aeration may be over stated. Think of the state of oil at the rod bearings after it leaves rod bearing / crank journal interface. The reservation I have with DOF may be with my understanding of the system. After spending a few days perusing bearing manufacturing sites low speed bearings can be in an oil bath only partially submerging the lowest ball, or can have a DOF like system. High speed bearings use an oil mist system for longest life. Does the DOF squirt a stream of filtered oil or mist oil? I don't know, but I assume a stream. A stream of oil on the internal workings of the bearings would put an additional side load, a point load, on the moving internal bearing components that quite frankly, I've not seen quantified. Splash oil appears to be a non starter for 6204 steel bearings, but may be useful for the 6204 ceramic or larger steel bearings. Replacing the IMSB with a plain bearing is all about the plain bearing design. Is there enough real estate in the area around the IMS to float a plain bearing with the available oil pressure? Apparently so. If the sealed bearing could remain sealed retaining its grease, it would last the life of the other engine components (IMHO), or at least 90,000 mi in top gear.

[Jake Raby]

Is there enough real estate in the area around the IMS to float a plain bearing with the available oil pressure?

Yes, the opposite end of the IMS assembly (the end that NEVER has issues) is supported by a plain bearing that operates with less oil pressure than the IMS Solution sees.

The difference between filtered oil and just filtered oil requires first hand experience with the internal manipulation of these engines over and over and over again to understand. Thats the thing that most experts don't have.

[Johnny Danger]

Let's see? I just did the IMSB ceramic retro-fit at 22k miles. I average between 1-2k miles per year. If I need to change the bearing again after 40-50k miles, for me that would mean anytime between 25 to 50 years from now. Hmm... I should be all set for a awhile. By the way, do they allow Porsches in assisted living communities ?