Re: and withou test dsts, i agree eith the followin summary:

.... after my last video where I showed what happens to a spinning bearing filled with oil, some of you still had doubts and commented that in the real world, where the bearing is vertically positioned and partially immersed in oil, it would be different.
Well, here's my answer to that ...

[www.youtube.com]

Happy DOF'ing
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

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Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Thanks Pedro - that video pretty much looks as I had pictured it would go. The one obvious step further you could go is to show the DOF in action. Might be challenging but it would go a long way in convincing the skeptics.

Chris - '01 Boxster - Seal Grey / Black / Black ; '87 944 Turbo (track beast) ; '86 944 - needs a new home!

Could an open system like this cause foaming? If it did, then that could cause trouble as bubbles are bad for lubrication elsewhere in the engine. Isn't that a function of the AOS to remove foam?

I know oil is supposed to have anti-foaming agents in them, but getting rid of bubbles is so important, the engine must ensure no bubbles.

Do I have this all correct?

Peace
Bruce in Philly

Quote
Bruce In Philly (2000 S Boxster, now '09 C2S)
Could an open system like this cause foaming? If it did, then that could cause trouble as bubbles are bad for lubrication elsewhere in the engine. Isn't that a function of the AOS to remove foam?

I know oil is supposed to have anti-foaming agents in them, but getting rid of bubbles is so important, the engine must ensure no bubbles.

Do I have this all correct?

Peace
Bruce in Philly

are routed to the intake manifold and then on to the engine where they are burned.

There are two swirl pots that are fed oil from the scavenge pumps. These swirl pots are intended to separate the air from the oil, defoam the oil. They are not 100% efficient in their operation but the oil is routed to an area outside of the sump baffles so the oil has time to further shed its load of air naturally before the oil makes its way to the oil pump pick up tube. The oil pump pick up tube that is shrouded by the oil sump baffling. This is one reason why running the oil level too low is ill advised. The low oil level can result in some oil still with air in it getting ingested by the pump under some conditions.

Pedro,
Not to be critical, but, in order for this demonstration to mean anything, it should represent more what the actual condition in the motor is. The outer section of the bearing does not rotate, that motion alone is what was keeping the oil away from the bearing. You should secure the outer race and also try to put a divider to keep the oil to the open side of the bearing as in the car.
Secondly, what is the operating speed range of the ims? I'm fairly certain it is not the exact speed of the motor you have attached. Varying the speed of the motor, as in normal driving conditions (we don't all drive at full throttle as Guenter!) would also be helpful to see. It very well maybe that the engine rpm may have a big impact on oil movement around and in the bearing.
Again, I'm not trying to hamper your efforts, I just thought I would offer up some constructive criticisms before someone attacks your efforts. I'm glad you and others make efforts to better our cars, I have purchased several of your products, but as an engineer myself, I want you to represent this demonstration as accurately as possible so I can see for myself a truly representative demonstration of what is occurring inside our cars.

Steve

Steve
Guards Red 1999
I'm not a race car driver, but I play one in 2nd and 3rd gear

For some reason, I thought the outer race was stationary, not so! But do you think the cavity that the ims is in has any affect on splashing oil back onto the bearing?
I guess it takes until about 5pm for my brain to kick in!

Steve

Steve
Guards Red 1999
I'm not a race car driver, but I play one in 2nd and 3rd gear

Best demo yet, Pedro.

Seeing the bearing sit in oil makes you realize that it would likely only take about a quart below the full mark (a little over 2 segments of the oil gauge I believe) for the bearing to be almost totally above the oil surface. Sure makes a strong argument for your DOF.

First of all, the bearing will be completely out of the oil with the motor running. Go start your car and using the dipstick with the motor running, measure the oil level. It won't even register on the dipstick. So Pedro is right that you will get no direct oilong of the bearing. But his demo does not simulate real life splash oiling. I don't have a link, but there are several videos out there of a real motor running and the oil splash is like cloud, enveloping the entire crankcase with an oil rain.

So maybe splash oiling is sufficient, but I have to agree that direct oiling is probably better.

The IMS bearing is outer ring rotation and its speed is approximately half the crankshaft speed. When the engine is running the oil pump will be pumping oil to the main and rod bearings, camshafts, valves, piston squatters, etc. The oil level in the sump will be below the IMS bearing. The exposed end of the IMS is shielded by the end of the crankcase and will get very little oil splash, Probably why Porsche used a sealed, greased bearing.

Ed B
The bearing guy

Ed the bearing guy makes good points about why Porsche may have made the IMS a sealed bearing system. Have there been bearing failures with intact seals? Maybe this can't be answered because even if the bearings failed with the seal in place, the seal would be destroyed as the bearings disintegrated, but I think it is interesting. If the bearings fail with intact seals, then the bearings are bad. If the bearings only fail with a failed seal, then maybe it is really a seal problem.

Do the LN bearings have seals?

Pedro, does your DOF work best with or without a seal? Or for some reason is my thinking incorrect and the seal is not relevant to issues related to the bearings?

1999 Arctic Sivler/black/black (sold)
2008s Silver/black/black - so predictable
2011 Outback
8/24/2011 first Grandson

The LN and Pedro's repalcement have no seals. This is because they work on a different principle. The sealed bearings assume that the sump oil wont get in and thus yu need permanent grease. Problem is, they fail with time (lots of info and speculation on the method).

LN builds a more robust bearing, opens it up to splash lubrication and says that improves things. Pedro questions whether splash is sufficient.

DOF says "let's repalce the temporary grease with a permanent stream of oil". For this to work it MUST be open (unsealed) so the stream of oil cna get in. LN also makes on liek this but its a traditional bushing, not a ball bearing, and costs a lot. Its very likely that DOF with any solid bearing is very very good. Admittedly we cant have data for years.

If the seals were godo to higher temps maybe the saled unit would work. But as is, its an issue.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

The DOF requires the bearing to have the outer seal removed so that the oil can bathe the balls in cooled and filtered oil.
The inner seal remains in place to prevent oil from flowing back into the IMS.

The relevance of the seals and the IMS bearings is that the OEM is a sealed bearing with "lifetime grease", but when the seals fail (which many do) they allow the lifetime grease to be dissolved (washed) away and the bearing starts to run without the proper lubrication.
The first generation of aftermarket replacement IMS bearings was the LNE ceramic bearing.
LNE does not manufacture these bearings, they sourced them from a bearing manufacturer.
LNE removed the outer seal, shaved the race to size and machined a new, stronger than OEM bearing shaft and flange.
They (LNE) left the new bearing to be lubricated by whatever oil splash happened nearby.
Two things happened:
Because there was not enough oil splash, the first generation bearings with nylon cages were replaced with steel cages, but there are many out there with the weaker nylon cage which in some instances can break/melt.
The steel cage lasts longer than the nylon cage, but we have also found that the bearings start to wear considerably after about 40,000 miles.

So, our solution has been to provide the proper lubrication that is absent without a forced stream of cooled and filtered oil (Direct Oil Feed or DOF).
Repeating myself for the Nth time, we don't believe that the bearings are intrinsically weak, whether they are the OEM steel bearing or a replacement ceramic bearing from LNE or other vendors.
We believe the lack of proper lubrication/cooling is what does them in eventually.

Happy DOF'ing,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Repeating myself for the Nth time, we don't believe that the bearings are intrinsically weak, whether they are the OEM steel bearing or a replacement ceramic bearing from LNE or other vendors.

I agree. Just wonder if the LNE, for those of us who already bit the bullet, is good enough w/o.

I hate this keyboard (surface)

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

So how do you explain why single row bearings fail at least 8 times more frequently than dual row bearings when they have the same engineering design and differ only in their load carrying capacity?



Edited 1 time(s). Last edit at 11/18/2013 09:18AM by thom4782. (view changes)

Quote
thom4782
So how do you explain why single row bearings fail at least 8 times more frequently than dual row bearings when they have the same engineering design and differ only in their load carrying capacity?

... fail quicker than the dual-row bearings because they have half of the surface area of the dual-row.
If you were to put a quadruple-row bearing it would fail less than the dual-row.
But they all fail because of improper lubrication.
I'm convinced you love to hear me saying this, because you keep asking the same question over and over again and the answer won't change.

If it were like you're saying that the bearing is weak, then it wouldn't be an 8% or 10% or even 20% failure rate. It would be a 50% or higher rate!

Happy DOF'ing
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Minus 40 degrees... Is that Fahrenheit or Celsius?

...than a smaller one. Its still makes the problem lubrication But it also is why i still believe, or maybe hope, that the LN will also >> outlast the OEM single row bearings.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

Pedro:

You never answer my any of questions directly with objective facts to either contradict my fact-based conclusions or provide different facts to support your opinions. This is true on this forum as well as the 986 and Pelican forums.

I don't ever expect you to change your viewpoint I do believe others should be aware of different viewpoints, however, so they can make the most informed decisions possible.

Thom

The single-row bearings have less surface area of contact bearing the same load, hence more friction, hence shorter life. And with inadequate lubrication that level of friction causes significant wear.

Minus 40 degrees... Is that Fahrenheit or Celsius?

The front seal is removed with the DOF. Installing mine as we speak.