Scary rod bearing thread s85

[GIdriver]

Massive amount of good info here. Special thanks to BMRLVR, kawasaki and regular_guy for their contributions.

I think I will stick with TWS. Warm/hot weather all year long where I live, and I never push the car hard (keep it below 3k rpm) until temps are ~210F. Is my DD, most of the time driven easy on highway with a few spirited drives weekly. I do three to four 1/2 mile events/year. Has ~33k miles now. I'm changing oil ever 7.5k miles but will do it every 5k miles from now on. Will send oil for analysis to Blackstone on next change.

Can any of our experts give an opinion about sticking with TWS in my particular situation (hot weather all year long)?

[BMRLVR]

Originally Posted by GIdriver

Massive amount of good info here. Special thanks to BMRLVR, kawasaki and regular_guy for their contributions.

I think I will stick with TWS. Warm/hot weather all year long where I live, and I never push the car hard (keep it below 3k rpm) until temps are ~210F. Is my DD, most of the time driven easy on highway with a few spirited drives weekly. I do three to four 1/2 mile events/year. Has ~33k miles now. I'm changing oil ever 7.5k miles but will do it every 5k miles from now on. Will send oil for analysis to Blackstone on next change.

Can any of our experts give an opinion about sticking with TWS in my particular situation (hot weather all year long)?

Hot/warm weather don't really make much difference, the oil is still extremely viscous at 40 degrees c as indicated by the viscosity ratings of the TWS on the technical data sheet.

Since you mostly daily drive your car and only do occasional spirited driving you are the best type of candidate for the M1 0W40....... You are the type of person I was referring to when I stated TWS wasn't required for the S65.

IMO, you should switch to the 0W40 since it will most likely benefit you lots due to your driving style!
Edit QUOTE

[GIdriver]

Originally Posted by BMRLVR

Hot/warm weather don't really make much difference, the oil is still extremely viscous at 40 degrees c as indicated by the viscosity ratings of the TWS on the technical data sheet.

Since you mostly daily drive your car and only do occasional spirited driving you are the best type of candidate for the M1 0W40....... You are the type of person I was referring to when I stated TWS wasn't required for the S65.

IMO, you should switch to the 0W40 since it will most likely benefit you lots due to your driving style!
Edit QUOTE

Would you suggest using M1 0W-40 for racing events as well?

[OC ///M]

Originally Posted by GIdriver

Would you suggest using M1 0W-40 for racing events as well?

^ I believe this was answered here:

Originally Posted by BMRLVR

...As I have told you in a previous reply...I honestly don't see a problem with the 0W40 by itself...the Mobil 0W40 has plenty of viscosity at higher temps as shown by it's HTHS numbers. If you are going to track the car, put something heavier in or add some Mobil 1 15W50 as Kawasaki00 recommended...For strictly street driving, even hard mountain runs etc, the Mobil 0W40 is more than up to the task!

Huge to BMRLVR, Kawasaki00 and regular guy for sharing your knowledge & contributing to this thread and the community!

[kawasaki00]

Originally Posted by OC ///M

^ I believe this was answered here:



Huge to BMRLVR, Kawasaki00 and regular guy for sharing your knowledge & contributing to this thread and the community!

Thank you for the kind words sir, just as the rest of us just looking at making a great vehicle even better.

[kawasaki00]

Originally Posted by BMRLVR

Hot/warm weather don't really make much difference, the oil is still extremely viscous at 40 degrees c as indicated by the viscosity ratings of the TWS on the technical data sheet.

Since you mostly daily drive your car and only do occasional spirited driving you are the best type of candidate for the M1 0W40....... You are the type of person I was referring to when I stated TWS wasn't required for the S65.

IMO, you should switch to the 0W40 since it will most likely benefit you lots due to your driving style!
Edit QUOTE

I agree with all these points.

[e92zero]

Originally Posted by CSBM5

Re thinner oil: People here are far more qualified than me to give guidance, but what I would be concerned about is if wear has already occurred as in the case referenced. At that point, you have an unknown situation in the bearing to crank interface. If the surface roughness is greater than a unworn bearing (I would assume this is the case), then a "thick" oil film will likely be needed to prevent contact and wear of the surface asperities, perhaps even at "normal" rpms/load conditions. At that point in the bearing's wear cycle, I'm unsure about then switching to a less viscous oil since that will make the hydrodynamic oil film "thinner" in that critical interface. It would seem that the time to use 0W40 would be from the start...with fresh bearings?

That's a rough swag/thought on your question. I'm sure the guys here with empirical experience can chime in with more.

Can the 3 experts also comment on CSBM5 post? Thanks in advance.

[BIU]

Soaking this thread up like a sponge


Thank god for the tech gurus on this forum

[CSBM5]

For anyone with an engineering background that is now interested in bearings and such, one book I've read a good portion of is "Engineering Tribology" by Stachowiak and Batchelor. I see it is now available on Google Books.

Having brushed up on this subject, I know have more questions than I have answers witness the earlier posts I did on multi-weight oil non-Newtonian behavior for example -- I want modern data on modern multi-weight synthetic oils to see if they still have the rather severe viscosity reduction with very high strain rates (i.e. rod bearing oil wedge!) (there is one example chart in the book, see Figure 2.8, page 23, but this is referenced as being from 1982, so most likely is a dino oil). The issue at hand is the long chained polymers that provide the multi-weight behavior have their molecules align under high strain rates which gives a reduction in viscosity (and hence the non-Newtonian behavior as shown in that graph). I understand that (at least in the older days) the broader the weight classification of the multi-weight oil, the greater this effect. And that's just the beginning of what I need to ask...

[GIdriver]

Originally Posted by OC ///M

^ I believe this was answered here:

Thanks for the heads up. So much information in this thread one can get lost sometimes.

Originally Posted by BMRLVR

Hot/warm weather don't really make much difference, the oil is still extremely viscous at 40 degrees c as indicated by the viscosity ratings of the TWS on the technical data sheet.

Since you mostly daily drive your car and only do occasional spirited driving you are the best type of candidate for the M1 0W40....... You are the type of person I was referring to when I stated TWS wasn't required for the S65.

IMO, you should switch to the 0W40 since it will most likely benefit you lots due to your driving style!
Edit QUOTE

Will do. Thank's for the input. I guess I'll be saving a few bucks in the process

Originally Posted by kawasaki00

I agree with all these points.

Thank you as well, sir.

[BMRLVR]

Originally Posted by CSBM5

For anyone with an engineering background that is now interested in bearings and such, one book I've read a good portion of is "Engineering Tribology" by Stachowiak and Batchelor. I see it is now available on Google Books.

Having brushed up on this subject, I know have more questions than I have answers witness the earlier posts I did on multi-weight oil non-Newtonian behavior for example -- I want modern data on modern multi-weight synthetic oils to see if they still have the rather severe viscosity reduction with very high strain rates (i.e. rod bearing oil wedge!) (there is one example chart in the book, see Figure 2.8, page 23, but this is referenced as being from 1982, so most likely is a dino oil). The issue at hand is the long chained polymers that provide the multi-weight behavior have their molecules align under high strain rates which gives a reduction in viscosity (and hence the non-Newtonian behavior as shown in that graph). I understand that (at least in the older days) the broader the weight classification of the multi-weight oil, the greater this effect. And that's just the beginning of what I need to ask...

Synthetic oils of today can't be compared to hydrocarbon based oils of the 80's.

To answer your question, the VI of some of the best engine oils from 1982 were most likely 80-90 whereas today the VI of most synthetics is 150 or higher. The higher the VI the less viscosity change happens as temperature changes. These higher VI's are as a result of more advanced/stable synthetic base stocks
as well as more advanced additive packs and VII's which are much more resistant to thermal breakdown and shearing under excessive loads and temperatures.

[CSBM5]

Originally Posted by BMRLVR

Synthetic oils of today can't be compared to hydrocarbon based oils of the 80's.

To answer your question, the VI of some of the best engine oils from 1982 were most likely 80-90 whereas today the VI of most synthetics is 150 or higher. The higher the VI the less viscosity change happens as temperature changes. These higher VI's are as a result of more advanced/stable synthetic base stocks
as well as more advanced additive packs and VII's which are much more resistant to thermal breakdown and shearing under excessive loads and temperatures.

Thanks for the reply. Do you have any references I can refer to in order to read up on modern synthetic multi-weights? The only source I've found so far still discusses non-Newtonian behavior with shear rate and if shear rate gets high enough viscosity returns close to that of the base stock -- sort of the three regime type behavior: Newtonian like at no to moderate shear rate, non-Newtonian with higher shear rates, and then another non-Newtonian range (slope of the viscosity vs strain rate curve) with super high shear rates.

[BMRLVR]

Originally Posted by CSBM5

Thanks for the reply. Do you have any references I can refer to in order to read up on modern synthetic multi-weights? The only source I've found so far still discusses non-Newtonian behavior with shear rate and if shear rate gets high enough viscosity returns close to that of the base stock -- sort of the three regime type behavior: Newtonian like at no to moderate shear rate, non-Newtonian with higher shear rates, and then another non-Newtonian range (slope of the viscosity vs strain rate curve) with super high shear rates.

I am hardly qualified to answer your questions since my engine oil knowledge is limited to a few oil training courses that my employer has put me through as well as engine/hydraulic oil material that is part of obtaining your Interprovincial Government Mechanics License in Canada . I can interpret the additive pack requirements/viscosity requirements of a specific engine but tribology is a broad area that is very specialized and your questions should be directed to a qualified person since they are going beyond what I know.

Try asking the questions here: http://www.bobistheoilguy.com/forums...s.php?ubb=cfrm. There are lots of engineers/tribologists that participate on that site and they can answer your questions much better than me...... This is where I go for questions that are beyond my knowledge base. FYI, there is a member on there by the name of Doug Hillary...... He worked for Castrol way back when TWS was developed and was one of the people who helped engineer and test it..... Pick his brain, he can share lots of good info!

[CSBM5]

Originally Posted by BMRLVR

I am hardly qualified to answer your questions since my engine oil knowledge is limited to a few oil training courses that my employer has put me through as well as engine/hydraulic oil material that is part of obtaining your Interprovincial Government Mechanics License in Canada . I can interpret the additive pack requirements/viscosity requirements of a specific engine but tribology is a broad area that is very specialized and your questions should be directed to a qualified person since they are going beyond what I know.

Try asking the questions here: http://www.bobistheoilguy.com/forums...s.php?ubb=cfrm. There are lots of engineers/tribologists that participate on that site and they can answer your questions much better than me...... This is where I go for questions that are beyond my knowledge base. FYI, there is a member on there by the name of Doug Hillary...... He worked for Castrol way back when TWS was developed and was one of the people who helped engineer and test it..... Pick his brain, he can share lots of good info!

Thanks, will do. When I can formulate my questions well enough (probably going to do some more reading and web research/hunting), I'll make a post on that site.

Regards,
Chuck

[regular guy]

For the most part, the specs I posted came from memory of a two year-old build. Over the past few days, I was able to go back and look at the work sheet for the build and give the exact numbers that we measured. I doubt this will change much of the discussion, but I thought I owed it to this thread to provide updated information.

The good news is, the mains were a bit better than I remembered, but the bad news is the rods are almost exactly what I remembered.

The main clearances on the worksheet were as follows:
0.0016, 0.0016, 0.0018, 0.0020, 0.0017.

The rods clearances didn't really change from what I posted earlier. The worksheet from the full set of rod measurements is no longer available. But I did find the worksheet for the calculations to set the new rod bearing clearance. On the worksheet, it listed the measured (factory) rod clearance as 0.0011.

So the mains are a little better than I remembered, but the rods are still about the same.

[VCMpower]

Originally Posted by regular guy

For the most part, the specs I posted came from memory of a two year-old build. Over the past few days, I was able to go back and look at the work sheet for the build and give the exact numbers that we measured. I doubt this will change much of the discussion, but I thought I owed it to this thread to provide updated information.

The good news is, the mains were a bit better than I remembered, but the bad news is the rods are almost exactly what I remembered.

The main clearances on the worksheet were as follows:
0.0016, 0.0016, 0.0018, 0.0020, 0.0017.

The rods clearances didn't really change from what I posted earlier. The worksheet from the full set of rod measurements is no longer available. But I did find the worksheet for the calculations to set the new rod bearing clearance. On the worksheet, it listed the measured (factory) rod clearance as 0.0011.

So the mains are a little better than I remembered, but the rods are still about the same.

Good info. I have had a couple of these apart. Measured mine though. I measured rods .0014

[regular guy]

Originally Posted by VCMpower

Good info. I have had a couple of these apart. Measured mine though. I measured rods .0014

Let's put some real numbers down, see if we're in the same ballpark as each other.

We measured the mains as:
Bore: 2.36270, 2.36270, 2.36300, 2.36300, 2.36290
Jour: 2.36110, 2.36110, 2.36120, 2.36100, 2.36120
Clnc: 0.00160, 0.00160, 0.00180, 0.00200, 0.00170

Optimum clearance (0.001/journal-inch + 0.0005): 0.00286

Rods: As I mentioned, the original worksheet is unavailable. The measurements below are extracted from the original worksheet and were used to calculate the new journal size. So this is an authentic rod bearing measurement, I just don't have all eight of the originals to show.
Bore: 2.04830
Jour: 2.04720
Clnc: 0.00110

Optimum clearance (0.001/journal-inch + 0.0005): 0.0.00255

VCM, could you check your measurements and see how they stack up to these? I'd like to see which side (bore/journal) we are getting the differences in our measurements.

[aussiem3]

[rypik@BW]

I'm new into your community, hi there folks I just found your thread couple of minutes ago, and as i'm after some related works i could only add that after some discussion here we have also opted for too tight clearances for factory shells and rod. We found it at the very beggining just by looking at AZD/REPs@ista where clearances are shown, and it just looked not so ordinary for BMW engines we already looked deeply into.

It's obvious that in europe we have S65/S85 bearing issues as well, and i'll be posting bearing photos from upcoming works (at least 4 cars are queued for preventive mainetanance and 2 were done already within one month) to enhance this thread with some valuable knowledge which i think is already in this thread and really not much there is to say.

I just wonder why there are ones that believe that BMW is not responsible for topic issue. IMO they just wanted to sell a product which for most of users or rather abusers is something quite universal, that could be driven on daily basis without looking much into oil temp and all other technical stuff and without sacrificing something....they choose path that ended in this thread. Though not sure why really, keeping in mind that both of S65/S85 were new engines and it wasn't related to availability of shells sizes from mahle or any other vendor...

Within the specs that BMW opted for, it just could not be universal (in terms of bearing/rod specs and suggested oil) and everyone here should understand it and just live with it unless there will be some undersized solutions available, if they ever be at all...

I could admit that's not something that we expected, to get upper-classy engine with such surprise inside, but at the end of the day it's just an engine, not your leg neither liver..

I'll try to gather and post there some S85 related warranty numbers from my country, and check if there were any consistency concerning low-temp seasons, as i clearly remember two friends of mine who had their S85 blown nicely just after start in winter time. Always thought that running 10W60 whilst there is outside -15... -20 is not very smart idea which added to marginal clearances seems to be quite logic.

[BMRLVR]

Originally Posted by rypik@BW

I'm new into your community, hi there folks I just found your thread couple of minutes ago, and as i'm after some related works i could only add that after some discussion here we have also opted for too tight clearances for factory shells and rod. We found it at the very beggining just by looking at AZD/REPs@ista where clearances are shown, and it just looked not so ordinary for BMW engines we already looked deeply into.

It's obvious that in europe we have S65/S85 bearing issues as well, and i'll be posting bearing photos from upcoming works (at least 4 cars are queued for preventive mainetanance and 2 were done already within one month) to enhance this thread with some valuable knowledge which i think is already in this thread and really not much there is to say.

I just wonder why there are ones that believe that BMW is not responsible for topic issue. IMO they just wanted to sell a product which for most of users or rather abusers is something quite universal, that could be driven on daily basis without looking much into oil temp and all other technical stuff and without sacrificing something....they choose path that ended in this thread. Though not sure why really, keeping in mind that both of S65/S85 were new engines and it wasn't related to availability of shells sizes from mahle or any other vendor...

Within the specs that BMW opted for, it just could not be universal (in terms of bearing/rod specs and suggested oil) and everyone here should understand it and just live with it unless there will be some undersized solutions available, if they ever be at all...

I could admit that's not something that we expected, to get upper-classy engine with such surprise inside, but at the end of the day it's just an engine, not your leg neither liver..

I'll try to gather and post there some S85 related warranty numbers from my country, and check if there were any consistency concerning low-temp seasons, as i clearly remember two friends of mine who had their S85 blown nicely just after start in winter time. Always thought that running 10W60 whilst there is outside -15... -20 is not very smart idea which added to marginal clearances seems to be quite logic.

Thanks for adding to our thread. Please post any pictures/information you come across and we will try to help you/answer any questions we can!

[aussiem3]

Originally Posted by rypik@BW

I'm new into your community, hi there folks I just found your thread couple of minutes ago, and as i'm after some related works i could only add that after some discussion here we have also opted for too tight clearances for factory shells and rod. We found it at the very beggining just by looking at AZD/REPs@ista where clearances are shown, and it just looked not so ordinary for BMW engines we already looked deeply into.

It's obvious that in europe we have S65/S85 bearing issues as well, and i'll be posting bearing photos from upcoming works (at least 4 cars are queued for preventive mainetanance and 2 were done already within one month) to enhance this thread with some valuable knowledge which i think is already in this thread and really not much there is to say.

I just wonder why there are ones that believe that BMW is not responsible for topic issue. IMO they just wanted to sell a product which for most of users or rather abusers is something quite universal, that could be driven on daily basis without looking much into oil temp and all other technical stuff and without sacrificing something....they choose path that ended in this thread. Though not sure why really, keeping in mind that both of S65/S85 were new engines and it wasn't related to availability of shells sizes from mahle or any other vendor...

Within the specs that BMW opted for, it just could not be universal (in terms of bearing/rod specs and suggested oil) and everyone here should understand it and just live with it unless there will be some undersized solutions available, if they ever be at all...

I could admit that's not something that we expected, to get upper-classy engine with such surprise inside, but at the end of the day it's just an engine, not your leg neither liver..

I'll try to gather and post there some S85 related warranty numbers from my country, and check if there were any consistency concerning low-temp seasons, as i clearly remember two friends of mine who had their S85 blown nicely just after start in winter time. Always thought that running 10W60 whilst there is outside -15... -20 is not very smart idea which added to marginal clearances seems to be quite logic.

It is all about educating ourselves and others through experience and knowledge. Anything you may wish to contribute to accelerate this process is most welcomed. Go for it.

[kawasaki00]

A little something to add, I have been running the 0w40 mobil for a while now. I installed a gauge in the car to monitor OP. So far so good. I have got it to about 240 on the oil and still have 35psi at idle. At 210 oil I have 40psi. Full hot (240) is 80 at 8500 and 210 at 8500 is around 85-88
In conclusion the pressure is just fine for what we need. Although every car could be a little different I will have no problem running this oil from this point forward.
I never checked the pressure before the gauge install but now that I know there is good pressure I will never go back.