Another IMS bearing thread

[Jamesp]

So is the thought to run a pump inside the IMS shaft using the rotation motion of the shaft and the stationary bearing retaining stud? The oil then exits through an open bearing into the crankcase? I'm not sure what type of pump would lift the oil, but this concept is intriguing. Maybe some type of modified stator vane pump? First pumps air to create a vacuum and lift the oil, and then can handle oil as well? That would eliminate any new moving parts, make the stator and vanes part of a new stud and IMS tube closeout? Neat idea. Lots of technical challenges come to mind. Keep going and have fun!

[Walter White]

I'm looking at pumping the oil. It would be nice if it could be done. As I see it, the oil only has to be lifted about an inch. There are several types of pumps that may be viable. But yes I have considered the stator type too. Plan B is to be able to pump grease into the bearing. The biggest question now is can a tube fit down into the sump from the flange. Always looking for help. That's why I post the pics.

[Jake Raby]

Always consider the windage that your "fix" may create. Foamy oil has no film strength.
Nothing like solving one problem only to create another thats 10X more critical for the rest of the engine.

[Walter White]

It looks like there is plenty of space between the case wall and the end of the IM shaft for a tube in this picture. But is the shaft pushed back I wonder.
Another way to get to the oil may be through one of the lower bolts.

[Jamesp]

Originally Posted by Jake Raby

Always consider the windage that your "fix" may create. Foamy oil has no film strength.
Nothing like solving one problem only to create another thats 10X more critical for the rest of the engine.

Jake, I always go to the big knobs on a system. For windage I look at the crank/ piston/rod bearings as the main movers of air in the crankcase and for splashing/foaming oil. Add timing chains for splashing/foaming oil to the preceding and that's about it. Any other items appear to be second or third order effects. What am I missing?

[Jake Raby]

Anything that disturbs the oil, in any way will lead to added windage.

[BYprodriver]

Originally Posted by Jamesp

Jake, I always go to the big knobs on a system. For windage I look at the crank/ piston/rod bearings as the main movers of air in the crankcase and for splashing/foaming oil. Add timing chains for splashing/foaming oil to the preceding and that's about it. Any other items appear to be second or third order effects. What am I missing?

I'm thinking the pressure relief holes in your IMS are functioning like carb jets made to atomize & aerate fluids.

[Jamesp]

Originally Posted by BYprodriver

I'm thinking the pressure relief holes in your IMS are functioning like carb jets made to atomize & aerate fluids.

BYprodriver, here is the logic trail I followed along with "simpler is better" when I modified my engine by drilling carefully placed holes in my IMS shaft. "How much oil is in the IMS tube at startup? (maybe 8 Oz at startup) and how long will it be there? (maybe 10 seconds after startup due to the IMS spinning and casting the oil out the holes). Can more oil get into the IMS tube while it is spinning? (no, centrifugal force makes that impossible, the spinning shaft precludes that) where does the oil get slung for ~ten seconds? (onto the timing chains). How much effect does that have compared to the oil continuously spewing from the rod bearings as the crank rotates at thousands of RPMs slinging oil everywhere? (essentially nothing, not even in the noise) The real question here is whether oil can get past the IMS bearing seals to wash out the grease destroying the bearing without the differential pressure that is relieved by the holes drilled venting the IMS shaft. The seals on the bearings I removed looked great, and still were grabbing the inner race as one might expect from good seals. Still there was no grease in that IMS bearing. I think the answer is that the seals do maintain their design integrity but have oil under pressure pumped through them which washes out the grease. To retain the grease as expected by Porsche engineers the differential pressure across the IMSB can be eliminated by venting the shaft.