Official S65 Rod Bearing Condition Example Thread

[Green-Eggs]

Even the simplest, most basic examination of that oil flow graph disputes everything Pete is saying. But I love it when he tries match his engine knowledge against a NASCAR engine building superstar -- a guy who's engines are on the NASCAR podium almost every week, and often at the top of the podium. He's also a Guiness Book of World Records holder for engine building. Great way to pick a fight and lose.

[Green-Eggs]

Originally Posted by doogee

Thanks for the clarification. Totally understand pulling the bearings out again is a waste of your time!

Totally agree with you that a properly spec'd bearing doesn't need a coating. Mainly serves as a safety layer on cold starts etc.

I was never claiming that the bearings are no good because of the coating wear. It's going to happen period. I'll be doing a check on my VAC bearings shortly and if the coating has started to wear through it won't bother me as long as the bearing itself is in good shape. Depending on the wear pattern of course.

When is BE going to make a main bearing replacement for me I hope either BE or VAC is working on it, but I don't think they'd be interested for the size of the batch they'd need to sell.

OK, going to close the loop on this. Kawasaki confirmed my information that the coating is not designed to wear off. According to what I read, if the bearing was designed that the coatings will intentionally wear off, it's using an inferior coating. He also confirmed what I've been hearing on the west coast about Calico -- big race shops don't use them any longer and haven't for many years, and he mentioned quality control issues. In previous posts, I've mentioned our own quality control issues with Calico. I said we've sent multiple sets of bearings out to Calico for coating, and they all came back mixed up between uppers and lowers. Clearly poor quality control there. Bert mentioned that the two sets he measured were the same thing -- Calico mixed up the upper and lower shells. I'm not trying to beat that horse in the ground, just saying there's plenty of evidence to back up what Kawasaki has said, and it's been on the forums a few times before.

BE stands by using the Clevite TriArmor coating as superior to Calico. It's designed by the manufacturer, for the manufacturer's bearings. The Clevite catalog has dozens, maybe over 100 different bearing sets with the TriArmor coating. The clearances are always included with the coating, not without. Again, not trying to beat this horse into the ground, but it's more proof this is the right way to do it, not the other way around.

With that said, the only way to compare one to the other, is either clearances with coating or clearances without coating. As Kawasaki said, and I think I've demonstrated the same thing, you always assume the coating is part of the design and set clearances accordingly. You assume the coating is part of the design and does not wear off. The VAC bearings were clearly designed for OEM clearance, and they said so themselves. I hope this once and for all puts this comparison of clearances to rest.

[tdott]

Thanks all for the great discussion on the topic!

Now all who have replaced their rod bearings, let’s all prey we don’t ever have to deal with the main bearings going.

[Green-Eggs]

Originally Posted by doogee

When is BE going to make a main bearing replacement for me I hope either BE or VAC is working on it, but I don't think they'd be interested for the size of the batch they'd need to sell.

I checked with BE on this. To make a set of mains won't be cheap because there's four different bearing shells. Each shell needs its own tooling, and then there's a minimum order of 1000 pieces per shell. So if the tooling is $15000 and each shell costs $20, here's what the startup costs look like:
4x $15000 = $60000
4x $20 x 1000 = $80000

Total startup for main bearings: $140000.

That's why I don't think you'll see this any time soon.

[Sneaky Pete]

Originally Posted by Green-Eggs

Even the simplest, most basic examination of that oil flow graph disputes everything Pete is saying. But I love it when he tries match his engine knowledge against a NASCAR engine building superstar -- a guy who's engines are on the NASCAR podium almost every week, and often at the top of the podium. He's also a Guiness Book of World Records holder for engine building. Great way to pick a fight and lose.

Boom and there it is...the moment the counter argument ran out of steam. You can always tell, because that's when it becomes personal.
Don't get me wrong, I have the greatest respect for kawasaki00 however the logic has yet to be demonstrated to be unsound (a vested interest saying it's so, doesn't count).

Originally Posted by kawasaki00

The bypass regulator system was designed to provide said pressure off the stock flow rating. So when one ups the flow the bypass has no choice but to fall a few psi. If we could change the spring then the pressure would be the same with increased flow. Point being one cant keep pressure exactly the same while increasing flow without changing the bypass spring. If the pump really could not keep up a flow increase of 3gpm would cut the pressure by almost 25 percent

Is it not the case though that its the spring loaded slide valve in the oil pump body that controls the variable oil flow rate and the oil pressure (to 5 bar).

If oil pressure is 5 bar then it and the pump's oil flow output are in equilibrium.
If oil pressure is >5 bar then the spring loaded slide valve moves to vary the oil pump's configuration to reduce oil output flow until oil pressure returns to 5 bar.
Conversely if oil pressure is <5 bar then the slide valve moves to vary the oil pump's configuration to increase oil output flow until oil pressure returns to 5 bar.

Logically should an engine rpm point exist at which oil pressure remains at less than 5 bar its because resistance to the oil flow is insufficient to pressurise the system to 5 bar despite the spring loaded slider valve setting the oil pump to maximum flow output.

Its my understanding that the whole point of variable flow oil pumps is to reduce engine energy waste by eliminating excess flow capacity.
In stock configuration the pump has to have only enough spare capacity to account for wear and high oil temperatures. Having redundant extra capacity would defeat the whole purpose.

[Scharbag]

Originally Posted by Sneaky Pete

Its my understanding that the whole point of variable flow oil pumps is to reduce engine energy waste by eliminating excess flow capacity.
In stock configuration the pump has to have only enough spare capacity to account for wear and high oil temperatures. Having redundant extra capacity would defeat the whole purpose.

That is so wrong.

I wish there was a way to filter posts from people who choose to argue just for the sake of arguing. You never back up anything you say with fact AND you spout nonsense such as the above. It truly does detract from what could be a great discussion.

Welcome to Monday I guess.

[Sneaky Pete]

Originally Posted by Scharbag

That is so wrong.

I wish there was a way to filter posts from people who choose to argue just for the sake of arguing. You never back up anything you say with fact AND you spout nonsense such as the above. It truly does detract from what could be a great discussion.

Welcome to Monday I guess.

Please set me straight...no problem fella, I can take it if I am mistaken.

Mahle:
Engine accessories such as the oil pump and the coolant pump are essential for engine operation. However, the engine power required to operate these pumps is lost for the powertrain of the vehicle. This is why attempts are made to minimize losses in the engine accessories. Controlled oil pumps are a smart solution in this regard. They require little drive energy because they supply only as much lubricating oil as the engine needs and at the correct pressure—unlike non-controlled oil pumps. The patented MAHLE pendulum-slider oil pump is ideally suited for efficient control of volume and pressure.

BMW:

[deansbimmer]

Originally Posted by Scharbag

That is so wrong.

Some people just have too much time on their hands. The keyboard warriors only fool a few. In the end they're just seen as the token troll who has to have the last word in every debate. There's three or four of them on this forum. I think they're the same person or are in cahoots- I know a couple of them change their SN back and forth...

The members with the real understanding of these systems are in the shop cranking things out and working with customers. They don't have time to waste arguing on forums. It's a shame that someone can come on here and in a few sentences make a claim about something that would take a damn thesis to satisfy their belligerent demand for "proof" otherwise. Our best offense is to ignore them. I'm sure it drives them crazy.

[Scharbag]

Originally Posted by Sneaky Pete

Please set me straight...no problem fella, I can take it if I am mistaken.

Mahle:
Engine accessories such as the oil pump and the coolant pump are essential for engine operation. However, the engine power required to operate these pumps is lost for the powertrain of the vehicle. This is why attempts are made to minimize losses in the engine accessories. Controlled oil pumps are a smart solution in this regard. They require little drive energy because they supply only as much lubricating oil as the engine needs and at the correct pressure—unlike non-controlled oil pumps. The patented MAHLE pendulum-slider oil pump is ideally suited for efficient control of volume and pressure.

BMW:

No where in your attachment does it say that the pumps do not have extra capacity. If BMW, in addition to pooching the bearing design, also built and engine with 2 pressure compensated oil pumps that had no headroom, then they should just simply stop building engines and let Volvo supply them instead.

A pressure compensated pump will adjust pressure internally to maintain pressure and supply flow without having fluid pass over a relief valve (the system will still have relief, it should nominally not see flow if properly designed). The relief valve is what wastes energy by turning potential pressure energy into kinetic heating energy. So a double whammy for the system as you have to get rid of bleed heat. Hence the use of positive displacement pressure compensating pumps.

IF the S65 pump was borderline on flow capacity, it would be unable to maintain pressure at high RPM with the increased clearance that the BE bearings provide. Given the pressure drops marginally (~4%) and the flow increases significantly (3x+) at these high RPMs, we can conclude that the pump is performing as required and has adequate capacity.

As for the slight pressure drop, this is a result of the INTERNAL pressure compensation design of the pump (spring and sensing assembly is in the pump). As has previously been said, it would require changing the oil pump's internals to compensate for the very small pressure drop. Because the pressure is still perfectly acceptable for the S65, no one bothers to fiddle with the pump.

Before you respond - AGAIN - with some nonsense that the higher rod bearing flow is robbing the main bearings of oil flow, go read a hydraulic textbook and look at how oil flows through an engine. First, the text will tell you that hydraulics have a cross variable (pressure - generated by pump) and a through variable (flow - dependent on system resistances). Flow is dependent on pressure and system resistance. So, if you generate adequate pressure, you simply will have adequate flow. Which, as is demonstrated by the data collected and posted on this forum, the S65 oil pump can and does provide adequate pressure throughout the entire RPM range. Second, oil passes through the main bearing on its way to the rod bearing. So the main sees the system pressure FIRST.

An analogy to this is electrical systems. Place 2 100W light-bulbs in parallel on a 100 volt (pressure) system (I know it is usually 120V but this math is easier). You need ~2A of current (flow) and each gets 1A. Now change 1 of the lights to 200W. You now will need 3A of flow, and the 100W lamp still gets 1A and the 200W lamp gets 2A.

In reality, just like the S65 oil system, there are system resistances so there will be a nominal voltage change when increasing/decreasing system loading. There is nothing we can do about that and it is not worth worrying about if it is not significant to the system. If you can convince all of the professional engine builders that have chimed in, with hard data, that a 4% pressure drop is significant to the S65, I will happily admit I am wrong.

I would consider this dead horse fully kicked. I am now going to go back to engineering shit.

Later

[Scharbag]

Originally Posted by deansbimmer

Some people just have too much time on their hands. The keyboard warriors only fool a few. In the end they're just seen as the token troll who has to have the last word in every debate. There's three or four of them on this forum. I think they're the same person or are in cahoots- I know a couple of them change their SN back and forth...

The members with the real understanding of these systems are in the shop cranking things out and working with customers. They don't have time to waste arguing on forums. It's a shame that someone can come on here and in a few sentences make a claim about something that would take a damn thesis to satisfy their belligerent demand for "proof" otherwise. Our best offense is to ignore them. I'm sure it drives them crazy.

I know I should. I really do. But I just cannot.

I do really appreciate the information that the professionals bring to the table. As you said, they take time out of their busy lives to share hard won information with the community. And for that, they are often offered up a plate of shit for their trouble.

The internet is awesome, but it can also suck.

[Green-Eggs]

Originally Posted by Scharbag

IF the S65 pump was borderline on flow capacity, it would be unable to maintain pressure at high RPM with the increased clearance that the BE bearings provide. Given the pressure drops marginally (~4%) and the flow increases significantly (3x+) at these high RPMs, we can conclude that the pump is performing as required and has adequate capacity.

You'll notice Pete didn't actually say anything in his argument, it was all just words. It was a tangent to deflect attention away from looking at that graph and discussing what it shows.

Pressure is a measurement of resistance. Capacity is a measurement of volume. Pete doesn't understand this because he uses one in place of the other in his argument about pump capacity. The graph shows a doubling of oil flow (capacity) where it counts. The graph even shows an upward spike at the very end, thus proving in comical manner how wrong he is. Like I said before, even the most simple and fundamental examination of the graph proves the S65 oil pump has ample capacity and isn't anywhere close to running out.

[doogee]

Originally Posted by Green-Eggs

I checked with BE on this. To make a set of mains won't be cheap because there's four different bearing shells. Each shell needs its own tooling, and then there's a minimum order of 1000 pieces per shell. So if the tooling is $15000 and each shell costs $20, here's what the startup costs look like:
4x $15000 = $60000
4x $20 x 1000 = $80000

Total startup for main bearings: $140000.

That's why I don't think you'll see this any time soon.

I definitely didn't have any hopes.

I'll just buy some OEM bearings and use some sand paper.

[kawasaki00]

Originally Posted by doogee

I definitely didn't have any hopes.

I'll just buy some OEM bearings and use some sand paper.

Check crush on the factory install just like you said, then use sandpaper (1200) or scotch brite (red) the living shit out of the back of the shells. You can get a few 10ths out of that at least.

If someone wants to pony up some cash we would love to make main bearings also. Its just not financially feasible at the moment.

[kawasaki00]

Originally Posted by Sneaky Pete

Logically should an engine rpm point exist at which oil pressure remains at less than 5 bar its because resistance to the oil flow is insufficient to pressurise the system to 5 bar despite the spring loaded slider valve setting the oil pump to maximum flow output.

Its my understanding that the whole point of variable flow oil pumps is to reduce engine energy waste by eliminating excess flow capacity.
In stock configuration the pump has to have only enough spare capacity to account for wear and high oil temperatures. Having redundant extra capacity would defeat the whole purpose.

Your statement is true, but that is not the case of this pump. Lets say the point where it could no longer hold pressure is at 6k. Then from 6k up till max engine rpm as the flow rate continues to increase the pressure will continue decreasing. Like I said before it loses a few psi because the spring that is in the pump was made for stock flow. If the pump was at capacity the pressure graph would steadily fall as rpm increased.

[Shredicus]

Originally Posted by kawasaki00

Check crush on the factory install just like you said, then use sandpaper (1200) or scotch brite (red) the living shit out of the back of the shells. You can get a few 10ths out of that at least.

If someone wants to pony up some cash we would love to make main bearings also. Its just not financially feasible at the moment.

Come on guys, this is an M3 forum... Gotta be some venture capitalists or just general rich bastards out there that want to see this happen

[GORDON.M3]

Originally Posted by Shredicus

Come on guys, this is an M3 forum... Gotta be some venture capitalists or just general rich bastards out there that want to see this happen

I doubt they are driving a 10-year-old car/generation still, unless they are super attached to the E9x M3.

[jcolley]

Originally Posted by doogee

I definitely didn't have any hopes.

I'll just buy some OEM bearings and use some sand paper.

When I was looking for mains for the two oddball S85 builds I'm working on, I inquired with VAC about their coated mains. They only offer standard size for that reason of cost control. I opted to stick with OEMs, but started discussing with my machine shop how to resize all the main bores to the same (medium) spec with a billet crank. It's a convoluted process to be certain.

Mill the upper face of the bedplate a few thou. Mill the lower face of the block few thou. Intall time-serts on the main line. Check depth of bore to retain fit bolts. Torque bedplate. Bore and align hone the main line. Recut main seal bores. Split bedplate. Mill sealant channel back into bedplate if needed. Yep...they don't like me very much.

Far easier to have the crank made to the largest margin size and line hone the main so the largest shell gives the desired clearance.

[jcolley]

Originally Posted by Sneaky Pete

The problem is that pressure drop is due to the oil pump's flow capacity being reached. Spare oil flow capacity originally engineered into the OEM spec to account for wear, high oil temperatures etc now exits the extra clearance bearings instead.
Consequently any wear of extra clearance bearing coating, elevated oil temps and/or use of a thinner oil will result in a further drop in oil pressure.

You have:

- an assumption: margin to capacity for the pump was kept to a minimum. What your basis for this is, I have no idea.

- a theory: capacity being reached: seems to be based on your assumption

- ignored Bernoulli

Unless you have a means to prove the slide valve carrier has reached the end of it's travel, you have zero evidence to support your theory.

There's another wrench in the theory and assumption as well. You are looking at pressure in a viscous fluid system measured at a point well downstream of the point you're assuming changes. If the whole purpose of the slide valve carrier being balanced against a piston pushing against spring pressure, how can the pressure at that point be anything other than the set pressure within some margin of system stabilization time?

Flow in any fluid system causes head/pressure loss. The higher the mass flow rate of the system, the higher the head/pressure loss become. There will be a delta in pressure between the pressure source and the point of measurement downstream and that Δ is directly proportional to mass flow rate.

On the graph, pressure (both system and source (unmeasured)) rises as prime mover speed increases. The slide valve carrier tensioning spring (not to be confused with the pressure regulating spring) exerts force on the slide valve carrier to push it in the direction of maximum flow. Pressure(s) continue to rise until meeting the pressure needed for the given piston surface area to exceed spring pressure of the slide valve carrier actuating piston. This is evident on the graph as the rise in pressure vs. RPM begins to taper due to movement of the slide valve carrier against the tensioning spring. At that point, the pressure at the discharge of the pump (if if could be measured) is constant. If it were not, the slide valve carrier would just reposition to balance that spring back out.

The decline of pressure is present on the graph for both the OEM bearings and the BE bearings. This is direct evidence of the increasing ΔP along the system with increasing flow. You really can't make it any more simple than this.

You are correct...the BE bearings do cause a larger ΔP in the system...by design. They cause a larger ΔP because the entire goal was higher flow.

[Scharbag]

I bet that sneaky bastard is just sitting at home giggling that so many people wasted so much time responding to his bullshit.

My momma always said: don’t get into a mud fight with a pig cause you will both get covered in shit but the pig is having fun...

Monday is almost over now.

[jcolley]

Originally Posted by Scharbag

I bet that sneaky bastard is just sitting at home giggling that so many people wasted so much time responding to his bullshit.

My momma always said: don’t get into a mud fight with a pig cause you will both get covered in shit but the pig is having fun...

Monday is almost over now.

It's like Paul Yaw says...Bullshit Epidemic.

[Duk996]

Originally Posted by Scharbag

I bet that sneaky bastard is just sitting at home giggling that so many people wasted so much time responding to his bullshit.

My momma always said: don’t get into a mud fight with a pig cause you will both get covered in shit but the pig is having fun...

Monday is almost over now.

While in school the saying was "arguing with an engineer is like wrestling in the mud with a pig; after a while you realize the pig is enjoying it".

I'm surprised the discussion got this far w/out Bernoulli's name being invoked.

[admranger]

Originally Posted by kawasaki00

Check crush on the factory install just like you said, then use sandpaper (1200) or scotch brite (red) the living shit out of the back of the shells. You can get a few 10ths out of that at least.

If someone wants to pony up some cash we would love to make main bearings also. Its just not financially feasible at the moment.

Since making the bearings isn't financially feasible (clearly), would modifying stock ones in a controlled manner be? I could see the need for jigs to hold the bearings and then the appropriate sized boring tool(s) and then possibly coating them as a path forward.

However, I recognize that this is easier typed from my recliner than actually designed and completed by skilled people such as yourself.

Regardless, I've installed 3 sets of BE bearings so that's 3 S65 owners (me being one of those) that only have to worry about their mains now.