Sorry, but your test of the IMS isn't a realistic one, since you don't have the load on the bearing. The IMS bearing doesn't just operate in a state of free-wheeling, it has chains driven off of them with some serious loads.

Yes, I know it isn't, post 52 sorta explains this, and what I am doing.

Need a microscope but it felt good before and all races look good,hope this helps Timhttp://forums.pelicanparts.com/uploa...1331955648.jpg
http://forums.pelicanparts.com/uploa...1331955662.jpg
http://forums.pelicanparts.com/uploa...1331955677.jpg

Thanks Greg,
Looks like it could of gone many more miles.
Tim

1 day 8.5hrs and the seal is still holding, 4940mi.

Tim , just checked out the video, very cool job! well done let me know if you need chains ;) Do you have fans running on your lathe to keep the temp down a bit? Wonder if you could load it up like a dynamometer to put extra stress on the bearing? Greg

Greg, I am a little leary of adding any more stress to this lathe as it is operating out of its range of speed as it is. No fan, just took off a cover and the lathe bearings are down to 80 degrees.
I am thinking of buying a complete assembled long block,(I have a disassembled one here that might go back together) building a mount off one of the cam towers, and drive the engine from a cam gear with a big electic motor at 3450rpms, which will turn the crank at almost redline. That way I have a contained oiling system (no mess). start up will be interesting but once the flywheel get moving it will spin up.
Tim

I understand what you are doing, but the speed you are running the bearing at is actually making the bearing happier than it would be at a low rpm and isn't subjecting the seal to environmental operating conditions that effect its life. Most IMS bearing failures occur at idle or low engine rpm (cruising in top gear at 55-65 mph).

If it is the purpose of the test to evaluate the seal's integrity, duplicating typical operating conditions of at least temperature of the seal (if you aren't going to attempt to match the loads) would be of critical importance. We know that these engines run oil temperature of at least 15-20F over coolant temperature in the most mild of operating conditions. Using a heat gun or another source of heat at the bearing to get it up to say, a minimum of 210-220F (250-300F is possible in these engines) would be advisable, as that's the temperature Porsche is trying to get the oil to in normal operation to vapor off water from the crankcase, as that extends oil life and reduces the formation of acid in long drain intervals.

Hi Charles,
Thanks for the info, good idea with the heat gun. I should be able to bring it up to atleast 250F. This really isn't a test of the bearing, as I am sure you have done this already and came up with the best bearing possible. This is just the idea of using the IMS as an oil tank would even be feasible. And if the seal can go the distance of atleast 250,000mi. before leaking.

Once I am confident that this idea is good and the seal will not self destruct and can go the distance, I am installing it in my 98 for the real world test. I will most likely use your bearing as my thinking right now is this combo will last indefinitely.

2 days and 2.5hrs. without a hiccup, tomorrow the heat gun idea will be applied. 7676mi.

Feelyx - catching back up again. My bearing was easily 1/3 full, I was very surprised at how much oil came out. In your theory above you indicate the bearing was put on the inside, are you saying this happened all the time year after year. I've not seen one pulled yet that didn't have the seal on the inside. It actually seems like it would have been a good idea to have the tube filled and seal only on outside of bearing. If one takes the LN approach Porsche would have been better off not putting the seal on the outside after this mistake...at least it would have been exposed to some oil.

Hi Whip, Yes seal was inadvertently put inside instead of outside. No, just the first order of double row of bearings from NSK. Which was how many bearings? Enough to build engines through 99? I don't know,......, but I do know Porsche ordered them missing one seal and no lube. I was working on getting the info for the ordering of the second seal when they found out it was about Porsche, then NSK shut me down. Right now I am in communicating with a company about gear oils that was used in 96.

Like I said, I think there was a communication break down inside the company between Depts. I have seen it several times before in business as they would rather hide the mistake than expose it as their fault. This is just my theory and I am sticking to it, unless info comes to light that would change my direction here.

I am not sure if the steel balls in the original bearing would of lasted with the seal off in a dirty enviornment.

Everyone keeps saying engine oil entered the tube through bad seals but the bearing would have to be submerged in oil to have that much oil stay in the tube. Since the bearing isn't submerged, oil would drain out of the seals when it went bad.

Ya after looking at mine closely and talking to you in the past it seemed unlikely the substance in the tube was not from engine oil leaking through...though it was interesting there was clean oil in my bearing so it would seem possible it continued through the backside seal into shaft. Think I just contradicted myself.

Anyway based on your thoughts on the double row how does that explain the failure on single row in later years. Maybe you already talked about this and i missed it.

Right now I am working out the original design that Porsche "would of", "could of" used with the info I have collected. From there I think it all went down hill as bandaids on bullet wounds. As I think Porsche at first thought they had a design issue, and applied patches as a solution.
I believe Porsche had it right the first time, and just didn't know it.

3 days 2.5 hrs. still going strong, the heat gets applied tonight and will try and get a video up with a temp reading. I will have to stop the lathe to grease the gears in the lathe at that time.
11,324mi.
I will decide at that time if I go to a slower speed as Charles suggested.

Here is the video with the heat applied, I slowed down the lathe to 1200rpm so engine speed is 2400rpm. So now we are at approx. 52mph.
The IMS has been 3 days and 10.5 hrs at 152mph for a total of 12,504mi. and no leakage.
10:00 pm pst is the new start time at 52mph.
Next test is at 500rpm as an idle speed test.

<iframe width="420" height="315" src="http://www.youtube.com/embed/ms2dYZN9h8g" frameborder="0" allowfullscreen></iframe>

So the theory that open bearings are lubricated by oil is moot?

No, an open bearing would be lubed by oil, such as LN's ceramic can operate on very little oil. The chain from the crank to the IMS would drag up enough oil to keep it lubed. But if you put in a open steel bearing, there most likely wouldn't be enough oil to keep it cool and would over heat and sieze up.

update, i haven't burnt the place down yet, 16.5 hrs. no leaks from the seal.
858mi. SmileWavy

<iframe width="420" height="315" src="http://www.youtube.com/embed/_EiU75lxVUM" frameborder="0" allowfullscreen></iframe>

23.5 hrs and still movin' along..... 1222mi. @ 250F/260F....
1 day 9.5hrs...... 1742mi. @ 250F/260F....
1 day 21hrs...... 2340mi @ 260F/285F.....
2 days 6hrs,,,,,, 2808mi @ 250F/265F....
2 days 16 hrs..... 3328mi. 260F/275F.... I will have to repace the lathe bearings soon... LOL
2 days 22.5 hrs.... 3666mi. 270F/280F