Dual row IMS replacement now possible?

[mikefocke]

At http://www.flat6innovations.com/saving-an-...ne-ims-retrofit Jake has posted pictures of his experimental retrofit of a dual row IMS (later 986s and 987s IIRC) without having to completely disassemble the engine. The intent is to replace the lifetime lubricated IMS bearing Porsche used with a more robust bearing lubricated by the oil in the engine. Read to the end of the article and you'll see him discuss what he sees as the risks and that he is looking for people willing to be alfa testers of this process.

[Jake Raby]

This is not the first time that this has been done.. It just took us a while to put the pieces of the puzzle together and make it more of a streamlined procedure. There are dozens of cars out there that have used the procedure in the past, but they used a Porsche single row bearing with a spacer that makes up the difference in bearing width.

We certainly take no credit in finding the puller that allows this to be a reality, (that credit goes to Scott Slauson) but we are taking it a step further by having a specially designed bearing made that is more robust and more resistant to wear than the stock 10 dollar bearing that Porsche used in this position.

There are risks associated with the procedure, but I took those risks with one of our test cars that has a 40K mile engine installed without even blinking an eye.

Only time will tell, we will be pulling these bearings in test cars at some intervals to inspect them for wear and etc and also we'll be monitoring used oil samples to see if any new materials show up in the short or long term..

My car will be back on the road on Monday that has this bearing mod, I decided to pull it down for an intake cam enhancement while we were at it and had the tranny out and now feel confident that I'll be making much more respectable numbers as well :-)

[flyingpenguin]

Great stuff Jake!

I have been following your efforts for a while now and this seems like a pretty solid solution.

I have a 2000 996 with the 3.4 engine replaced in Aug-06 (the previous owner D-chunked it). I am mostly using the car for the track and am obviously concerned about the replacement engine bombing on me some day.

Would you recommend I sign up for your R&D program?

Joost

[pk2]

Looks intriguing. Is it suitable for earlier cars like mine?

Regards, PK

[Jake Raby]

Looks intriguing. Is it suitable for earlier cars like mine?

Regards, PK

The IMS Bearing retrofit is applicable to ALL M96 engines, despite year or model. The only exception are those engines with the latest generation bearing updates from Porsche, these are the replacement engines currently being sold.

[jmatta]

Jake, I read your write up with great interest, but do have a question. I thought I'd read in prior comments that the dual row bearing was actully larger than the outer diameter opening in the case? After looking at your photos, this is obviously not true. It appears the difference is the retaining clip that collapses when you pull the bearing with the special tool Charles devised. That sucker must be pressed in really tight from your comments about forces and possible case breakage.

Thanks for the great write up!

[Jake Raby]

The only bearing thats larger than the opening in the case is the unit that is used in the Gen II 997 engines as well as the Porsche remans and new engines...

[Steve Tinker]

Jake, what's the situation for us poor guys on the other side of the pond who would like to sleep real easy at night by retro fitting one of your double row bearings? Is there going to be a kit (bearing/puller/instructions/etc) available over the counter and could it be performed by an indipendant Porsche mechanic. Or are you saying that fitting is too tricky and that (at the moment) only you guys are installing them?

Boxsters here in Oz cost more than double what you pay, so we have a lot more $$ invested in our cars, so a Raby bearing retro fit would be more viable than a reman motor from Porsche (which costs here about the same as an acre block in Manhatten).

My 2001 Boxster S has "probably" got the double row bearing fitted and a couple of thousand dollar preventative maintenance up front is a hell of a lot better scenario than a possible engine black hole.

[mikefocke]

What I think Jake has said is

that he is working towards a kit with parts, instructions and tools. But right now he isn't sure enough of the workability of the procedure on every car and wants many more cars and miles in test vehicles before he is sure enough to release into the wild. That is why he is asking for volunteers to be fitted at his shop where he has control of the process and can learn the many variations of product Porsche produced until he is assured that the procedure can be trusted to a first time installer.

It's pretty serious because once you start pulling that bearing, if something goes wrong your next step is drop the motor and disassemble the whole engine. Lots of AU or US dollars. So he is right to make sure that it works repeatedly and that the fix lasts under all driving conditions.

I shudder at the legal implications. Jake get a good lawyer to go over the disclaimers when you do release your instructions.

See the last couple of paragraphs of explanation in his writeup on the dual bearing experiments for his own words on this. I hope I've described his intent correctly from memory.

[Steve Tinker]

Thanks Mike - I will stand in line with the (many) others who no doubt are following this with interest.......

Steve

[Jake Raby]

Mike is 100% correct in his post concerning the future for this bearing kit.

If we encounter ONE engine that can't have the bearing pulled, I'll not offer the kit because at that point a preventive ends up compromising a complete engine.

At the present we are working to save engines that are already failing. These already have rattles, rumbles and leaky IMS flanges already so if they end up having to be dismantled, so be it.. Its no loss.

IF this ends up being sold a sa kit you can bet there will be a twop page long disclaimer that details why we are not libel for issues related to this procedure. The variables and risks are numerous and unless a vehicle is in my shop for the work I care nothing about dealing with the risks as of today..

I want to make it clear that I have no doubt that the bearing that we are using is superior and is overkill for the task, my reservation is limited to the original bearing extraction procedures and the risks involved with them.

Another car hits the road today with the bearing installed..

[Bladecutter]

Mike is 100% correct in his post concerning the future for this bearing kit.

If we encounter ONE engine that can't have the bearing pulled, I'll not offer the kit because at that point a preventive ends up compromising a complete engine.

Jake,

Are you now saying that it looks like the upgrade can be applied to the '97 to '99 2.5 engines?

I had thought that you mentioned at one point in time that it's IMS bearing is entirely different in comparison to the 2000 and newer designs.

BC.

[Jake Raby]

Are you now saying that it looks like the upgrade can be applied to the '97 to '99 2.5 engines?.

Read the article!! The car in the article is a 98!!

I had thought that you mentioned at one point in time that it's IMS bearing is entirely different in comparison to the 2000 and newer designs

Thats correct.. Until this development we had never been able to remove the dual row bearing before..

We were proven wrong, but thats a very good thing!

[Bladecutter]

Are you now saying that it looks like the upgrade can be applied to the '97 to '99 2.5 engines?.

Read the article!! The car in the article is a 98!!

I just read through the article, and that's great news for all of us Boxster owners!

Although, no where in the article did you mention that the car being worked on was your normal '98 2.5 equipped test car. ;)

Also, I have had another question bouncing around my brain for a while ever since seeing the tear down and rebuild article of the Boxster engine that was put up a couple weeks back. It concerns the need to use a tool to insert the piston wrist pin retaining clips.

I was wondering if you had ever considered simply tapering the bottom of the piston bores in the crankcase half for the 2,4,6 cylinder head, so that you can fully assemble the pistons to the connecting rods, and then just simply slide the crankcase half onto the pistons without having to use the tool, and run the risk of having that retaining clip either not be properly installed, or pop free before installation, thus requiring full disassembly of the engine again?

Just about every motorcycle engine I have ever worked on simply requires the piston ring gaps be set to their proper positions, the piston, rings, and bores are then well lubricated, and the bores are gently tapped into position due the to bottom of the bore being tapered.

There obviously must be extra material outside of the piston travel section of the cylinder bores in order for there to be a hole placed to allow the insertion of the wrist pin retaining clip tool, so I was thinking that that area could be the tapered section that would allow you to simply slide the bores onto the pistons.

Chances are you have probably long since thought of that, and ruled it out, but I would love to hear the explanation of why that wouldn't work with this engine for the one cylinder head.

Thanks,

BC.

[Jake Raby]

I just read through the article, and that's great news for all of us Boxster owners!

Although, no where in the article did you mention that the car being worked on was your normal '98 2.5 equipped test car.

This particular car was not.. It was a 98 Owned by a Customer thats in Atlanta. My test car also has the bearing implemented, but it was already done when this article was put together..

Also, I have had another question bouncing around my brain for a while ever since seeing the tear down and rebuild article of the Boxster engine that was put up a couple weeks back. It concerns the need to use a tool to insert the piston wrist pin retaining clips.

The pictures do not do the components and the challenge the assembler has to overcome justice.

I was wondering if you had ever considered simply tapering the bottom of the piston bores in the crankcase half for the 2,4,6 cylinder head, so that you can fully assemble the pistons to the connecting rods, and then just simply slide the crankcase half onto the pistons without having to use the tool, and run the risk of having that retaining clip either not be properly installed, or pop free before installation, thus requiring full disassembly of the engine again?

**** right, that was one of the very first things we tried. I even had a special set of ring compressors made that would allow this.. There is NO WAY to do this without taking more risks of more severe damage to components. This is due wrestling a 55 pound, very bulky crankcase half onto THREE pistons at once, all at different phases of stroke.

Just about every motorcycle engine I have ever worked on simply requires the piston ring gaps be set to their proper positions, the piston, rings, and bores are then well lubricated, and the bores are gently tapped into position due the to bottom of the bore being tapered.

Thats because the cylinders are either individual units and installed as such or at most they are siamese units that do not weigh 55 pounds!

I assemble all our aircooled Porsche engines with the method you refer to, but this engine is impossible to assemble in this fashion- if you saw one up close and personal you'd see why.

There obviously must be extra material outside of the piston travel section of the cylinder bores in order for there to be a hole placed to allow the insertion of the wrist pin retaining clip tool, so I was thinking that that area could be the tapered section that would allow you to simply slide the bores onto the pistons.

There is enough room for this, but there is no way to get inside the case half to even hold the pistons for assembly into the bores.

Chances are you have probably long since thought of that, and ruled it out, but I would love to hear the explanation of why that wouldn't work with this engine for the one cylinder head

I hope I addressed it well enough.

I learned long ago that there are time that we do what is required, taking the time to do the procedures required. If we lose a clip inside the engine we have to also do what is required. (and some people wonder why what we create isn't cheap!)

This is just part of playing the game for us and if it wasn't a challenge I'd have zero desire to work with the engine..

[Bladecutter]

Hey Jake,

Thanks for all the information, I learned quite a lot from what you just provided.

I wouldn't have expected the case half to weigh 55 lbs, but I can definitely understand that it would be very difficult for one person, or even two people, to juggle that engine half, and keep the pistons in proper position in order to assemble things.

From all the various photos that I have seen of the Boxster engines, I have seen so many different similarities to the motorcycle engine world, which is my preferred tinkering point. And yes, there aren't many motorcycle cylinder bores that are 55 lbs each, though my guess would be that the Flat 6 engine in the Honda GoldWing and Honda Valkyrie would most likely be the closest in complexity to the Porsche engine.

It would be interesting to see a side by side breakdown of the two engines.

Now you've given me something to search for on the internet!

Thanks Jake,

BC.

[Jake Raby]

You won't find many pictures of an M96 online... There are a few, but until last year you could count them on one hand and thats primarily due to the fact that so few people have seen these engines internally and fewer have ever built one...

The M96 case half is huge compared to any motorcycle engine and it's bulk is much more difficult to work with than the weight..

The major issue is holding the rod/ piston assembly in the position necessary for installation, since ANY tool that would be used for this could not be retrieved after the block half was put into position over the 3 pistons..

More than likely all of this work would do nothing more than slow the process down, after you have done this procedure it becomes second nature and we have made some revisions to some of our updated parts that make it more easy to install the tools and the clips.

In our training classes we'll be giving the students first hand experience with the piston install procedure in an actual block half set up to practice the procedure.. Before I attempt to do this procedure on any engine I practice it and that makes the event much more simple and less risky.

I see people work twice as hard trying to save themselves time or money.. Just suck it up and do whats required! The engine isn't smarter than a human..

[atmorris]

The only bearing thats larger than the opening in the case is the unit that is used in the Gen II 997 engines as well as the Porsche remans and new engines...

So Porsche is now using their "latest" IMS bearing solution on all the rebuilt M96 engines and new (replacement) M96 engines then ? Interesting....

[Jake Raby]

Yes, every unit I have seen has had this, including a 3.2 thats still in the crate on the floor in front of me..

[Jay H]

So Porsche is now using their "latest" IMS bearing solution on all the rebuilt M96 engines and new (replacement) M96 engines then ? Interesting....

That seems to be very typical Porsche behavior. Quietly modify the offending part, then release only that part.

I just had my RMS replaced. I was led to believe Porsche is on their 4th revision of that seal...

I'll bet that in time, we'll see the 2006 - 2008 Boxsters as extremely reliable cars with this new IMS bearing update...

Edited May 14, 2009 by Jay H

[aracerx]

am getting ready to do another rms and wondered if I should use a different seal and tool from prior jobs? this is a 00 996 not gt3. thanks...should the IMS bearing be replaced always as a matter of caution on a 40K engine?

[marine8541]

This is not the first time that this has been done.. It just took us a while to put the pieces of the puzzle together and make it more of a streamlined procedure. There are dozens of cars out there that have used the procedure in the past, but they used a Porsche single row bearing with a spacer that makes up the difference in bearing width.

We certainly take no credit in finding the puller that allows this to be a reality, (that credit goes to Scott Slauson) but we are taking it a step further by having a specially designed bearing made that is more robust and more resistant to wear than the stock 10 dollar bearing that Porsche used in this position.

There are risks associated with the procedure, but I took those risks with one of our test cars that has a 40K mile engine installed without even blinking an eye.

Only time will tell, we will be pulling these bearings in test cars at some intervals to inspect them for wear and etc and also we'll be monitoring used oil samples to see if any new materials show up in the short or long term..

My car will be back on the road on Monday that has this bearing mod, I decided to pull it down for an intake cam enhancement while we were at it and had the tranny out and now feel confident that I'll be making much more respectable numbers as well :-)

Hello Jake,

While I thank you for the credit for the puller I have been replacing these for several years and not with a single row roller or what L&N is selling. This information was all given to Wayne R. Dempsey CEO, Pelican Parts Inc who has apparently given it out to L&N etc. This and other information was specifically told to Wayne D in confidentiality until the release of his latest book as most of it was considered proprietary. This was to be then released with a kit that I would offer at a very good price and done more for the community. This kit would be at a fraction of the price that L&N is selling them for .

Should anyone have further questions please contact me at the email that I have used in the PCA for years Marine351@aol.com .

Many Porsche enthusiasts should know me from the PCA, Softronic ,PCNA or many Technical Bulletins.

Best Regards,

Scott Slauson