DOF IMS Bearing - remove 1 seal/pierce the other?
 

We are installing a DOF IMS bearing in a 5-chain 2002. Instead of removing both rubber seals, how about just removing the outer and poking some holes on the inner? Filtered oil is flowing from the outside in to the IMS interior.

The DOF instructions do not call for the removal of both seals on the bearing, just the outside seal.
Leave the inner seal intact. You don't want the IMS full of oil.
Happy Boxstering
Pedro

2002 Boxster S 5-chain 97K hard miles. IMS bearing NSK 782 6204DU17 ENGLAND in perfect condition observed visually. Seals removed; no evidence of any grease, all surfaces oil covered. About 1/2 cup of dark oil recovered from IMS. The oil from the IMS is compared with oil from the engine in an attached picture. A lot of oil apparently has made it through the bearing seals over time and miles. Removing BOTH SEALS would let the engine communicate with the IMS directly. With the IMS so low in the engine, the bearing would appear to only be protected from debris by the fresh, filtered DOF spray. The engine oil quite apparently gets by the bearing seals into the IMS, but does not get out so easily. The fresh, clean DOF oil continuously sprayed onto the outside of the bearing would likely ameliorate the old, possibly rancid and acidic, oil seeping through the inside seal from the IMS. Ummm? When in doubt, go with the recommendation of only removing the outside seal? I'll think about it for a bit before pulling seal/s.

A stupid question, what about the kits that run a oil line to the IMS bearing ??

This is really simple.

If you use a sealed bearing, it must be lubricated internally period.

On the other hand, if you use an unsealed bearing, you remove the outer seal to allow oil to lubricate it. The LN Retrofit experience shows that splash oil from the sump is sufficient for the unsealed ceramic bearings to last well beyond 50,000 miles before considering a replacement.

Whether you add DOF or not, you do not remove the inner seal. If you do, oil will accumulate in the IMS tube.

Note that the "Eternal Fix" has no seals and has a flooded IMS. I am not saying that is good or not.

This post is related to the IMS Bearing Direct Oil Feed (DOF)® kit from DIRECT OIL FEED (DOF) FOR IMS BEARINGS | TuneRS Motorsports

The IMS Solution is a plain bearing replacement option for single row bearing cars. It is lubricated by a direct oil feed from the filter assembly. The feed is part of the IMS Solution package.

Single and dual row, unsealed ball bearing IMSs require external oil for lubrication. As I said in my prior note, the LN Retrofit history shows splash oil is sufficient. While there is no objective evidence in my view to show oil feed kits will materially extend bearing lives further, other people hold the opinion that these kits do extend operating lifetimes. In this sense, the merits of these kits comes down to who's opinion do you trust.

thom4782 is referring the direct oil feed onto a plain bearing instead of either the roller bearing of the "Eternal Fix" by European Parts Solutions (oil flooded IMS) or the TuneRS DOF (earlier post).

Both the IMS Solution and the DOF rely on oil "sprayed" onto the front surface of either a plane bearing or a ball bearing respectively. Note that the oil has nowhere to go except back to the pan dripping off the front surface of the associated bearing. Not ideal IMHO (maybe see Pedro's Garage splash YouTube videos? https://www.youtube.com/watch?v=qj06dqBk0to )

Incorrect. The IMS Solution delivers oil through the bearing flange to both the radial and longitudinal load bearing surfaces without loss of control through "spraying". This oil is delivered to these areas where it creates hydrodynamic and hydrostatic load carrying capability. At no time does the oil supply for the IMS Solution "spray" oil within the engine.

Incorrect. Just like the oil returned from the layshaft of an aircooled Porsche/ GT3/Turbo and all rod and main bearings within the engine, the spent oil simply returns to the sump without creating further windage within the engine. The design of the IMS Solution offers very little waste oil to return back to the sump, since the unit meters the oil thats used dependent upon RPM and volume. This is much different than spraying oil uncontrollably against the face of a dynamic component as you have specified.

The opposite end of the IMS, which is also a plain bearing,(very similar to the IMS Solution) from the factory returns the oil to the sump in the exact same manner as the IMS Solution. People tend not to understand that; because they either don't want to, or because they don't know how both ends of the IMS assembly is supported.

One of my biggest concerns through the development that went into the IMS Solution was combating windage and the tendency for oil to foam, especially at high RPM. Aerated oil loses film strength and won't build pressure, which leads to engine- wide issues.

So....without starting a fight
 

What is the best solution ???

Which has the most empirical data

The "IMS Solution" has some appealing aspects with oil delivery as mentioned. The two parts of the plane bearing being 27 attached to the IMS internal to the engine and 45 attached to the engine housing. The oil delivery, as you stated, is through the bearing flange, part 45, to both axial and radial load bearing surfaces. The axial load, and end play issues, must be minimal or neither this type of bearing nor the "Eternal Fix" could ever work. The oil that is supplied to the radial surface of 27 must seemingly exit along the axial surface of part 24 into the IMS and at the other end of 27, along the axial surface of the circlip part 32 and returning to the oil sump. These circumstances have obvious conclusions. Perhaps my assumptions are incorrect. If practical, you might elucidate on this matter pedagogically but not heuristically.

Both the "IMS Solution" and the end bearing on the sealed end of the IMS are plain bearings; the oil paths share similarities. We both understand the simple oil path return to the sump for the end bearing.

Waste oil does not exit at part 24. The IMS tube is fitted with a plug that is designed to keep the oil exiting between part 27 and the male end of the flange. Part 27 includes a design integration that promotes oil shedding at this point, during operation. This doubles to act as a safety for cold starts before oil pressure is achieved.

The IMS Solution was the very first IMS Retrofit technology that we invented. It has more developmental and practical application time than any other product we've released to date.

Ceramic or Steel
 

Which is better ?

All other specifications being equal, ceramic is likely "better".

Steel bearings are inexpensive and available from the high quality brands NSK and SKF. (about $15 for a single row and $50 for a double row)

Hybrid ceramic bearings apparently have an excellent reputation; you will need to do some research if you want to avoid Chinese bearings. Costs seem about triple that of steel.

IMHO...

The IMS Solution is best retrofit for single row cars because plain bearings do not fail catastrophically as ceramic and steel ball bearings do when they collapse.

The Gen 2 Single Row Pro IMS Retrofit is the next best option for single row cars because its design allows it to carry loads almost as high as dual row bearings

Ceramic ball bearings are the third best replacement for single row cars and the best option for dual row cars because ceramic balls last longer than steel ones on tough operating environments.

Depends upon whose bearing it is. The right ceramic bearing should run rings around a steel counterpart; that said, not all ceramic bearings are the same, as some have discovered to their detriment. LN Engineering developed their own bearing system, experimenting with different materials both for the balls and the cages before settling on the design marketed. The resulting product is made exclusively for them, and is not available "off the shelf", regardless of what many seem to think.

And their design works, with over 10,000 installations there have only been a handful of failures, most related to poor installation techniques, retrofitting an engine already full of metal grit from an existing IMS failure, or contamination of the bearing by metal from an unrelated engine component failure.

Soon that number will be doubled, its already near 18,000 for all the various LN/ IMS Solution offerings. There were 350 installs last month alone.

DOF IMS bearing is in. Outside oil seal removed as suggested by Pedro.

The instructions call for: "Working from the top of the engine, remove the factory oil port plug on the left side of the top of the engine, next to the air filter box and
under the rear end of the fuel injector bar (on the Boxster)."

The oil port refused to come loose. Eventually I resorted to extraordinary means. I don't imagine anyone envisions this approach to remove a little plug.