OEM 702/703 to BE Bearings

[JRV]

Got them swapped yesterday thanks to IMG and Corry. Using OEM rod bolts and AMSOIL 5w-50. So far haven't noticed much except a little smoother probably due to oil change. Motor has 49,750k miles, never tracked. It's always driven lightly until full warmed up and even then all I really do is cruise at about 4-4.5 with occasional whomping going on freeway. Oil changes after 16k miles were done anywhere between 3k-7k miles.
Anyway, I don't think they should look like this. I'm glad I did them, now feeling more eat ease. What do you guys think of these?

[rcracin]

Nice! Corry and Izzy ftw

[Stainless 45]

Look just like mine did. Worth it to get them done.

[admranger]

Any used oil analysis results before you changed them?

[Rajmun340]

Originally Posted by JRV

What do you guys think of these?

What i think... back when ethanol was not powering combustion engines the oil industry had to make much better refined gasoline because MBTE and before that lead were poor octane boosters. Now they rely so much on ethanol to boost octane level their base mix is much poorer quality which reduces refinery costs and boosts profit too. No problem because modern engine DME can compensate for fuel right ? Yes but that's a simplified view of a much larger problem. Ethanol completely changes the combustion reaction, it is an oxygenate and it has an hydroxyde OH group that gasoline does not have. What happens in the combustion chamber with ethanol + gasoline is extremely complex but the result is the CO carbon monoxide does not immediately convert to CO2 only when all the gasoline in the charge has finished burning does the ethanol burn and convert all CO to CO2 and it burns much faster causing pressure spikes in the cylinders. That alone does not cause worn bearings but ethanol also dilutes the oil and has a corrosive effect on bearings. Galvanisation or aluminium alloys to protect against corrosion does not stop or prevent corrosion it only slows it down.

Bearing corrosion by ethanol diluted in the oil + sudden high pressures in the cylinders due to fast ethanol burning after all the gasoline charge has burned (which the cooling presence of ethanol slows down) is what causes bearing to wear faster. The oil lubricity power is broken by ethanol. High RPM dilutes the oil faster with ethanol. Bearing corrosion can not be detected by Blackstone oil analysis as they use a spectroscopy method which only detects the levels of each elements not molecules.

Using ethanol free gasoline basically suppresses all risks of premature bearing wear.

[aussiem3]

Originally Posted by JoeM3SSII

What i think... back when ethanol was not powering combustion engines the oil industry had to make much better refined gasoline because MBTE and before that lead were poor octane boosters. Now they rely so much on ethanol to boost octane level their base mix is much poorer quality which reduces refinery costs and boosts profit too. No problem because modern engine DME can compensate for fuel right ? Yes but that's a simplified view of a much larger problem. Ethanol completely changes the combustion reaction, it is an oxygenate and it has an hydroxyde OH group that gasoline does not have. What happens in the combustion chamber with ethanol + gasoline is extremely complex but the result is the CO carbon monoxide does not immediately convert to CO2 only when all the gasoline in the charge has finished burning does the ethanol burn and convert all CO to CO2 and it burns much faster causing pressure spikes in the cylinders. That alone does not cause worn bearings but ethanol also dilutes the oil and has a corrosive effect on bearings. Galvanisation or aluminium alloys to protect against corrosion does not stop or prevent corrosion it only slows it down.

Bearing corrosion by ethanol diluted in the oil + sudden high pressures in the cylinders due to fast ethanol burning after all the gasoline charge has burned (which the cooling presence of ethanol slows down) is what causes bearing to wear faster. The oil lubricity power is broken by ethanol. High RPM dilutes the oil faster with ethanol. Bearing corrosion can not be detected by Blackstone oil analysis as they use a spectroscopy method which only detects the levels of each elements not molecules.

Using ethanol free gasoline basically suppresses all risks of premature bearing wear.

How widely is ethanol available NA? If this is true, it explains the large numbers of RB failures we're seeing there. This is the first time this argument has come to light. Anyone wish to challenge this theory?

[OM VT3]

Originally Posted by aussiem3

How widely is ethanol available NA? If this is true, it explains the large numbers of RB failures we're seeing there. This is the first time this argument has come to light. Anyone wish to challenge this theory?

Look at the numbers of cars and where they are.....this is why we are seeing them there

[JRV]

Originally Posted by admranger

Any used oil analysis results before you changed them?

Negative on that

[JRV]

Originally Posted by JoeM3SSII

What i think... back when ethanol was not powering combustion engines the oil industry had to make much better refined gasoline because MBTE and before that lead were poor octane boosters. Now they rely so much on ethanol to boost octane level their base mix is much poorer quality which reduces refinery costs and boosts profit too. No problem because modern engine DME can compensate for fuel right ? Yes but that's a simplified view of a much larger problem. Ethanol completely changes the combustion reaction, it is an oxygenate and it has an hydroxyde OH group that gasoline does not have. What happens in the combustion chamber with ethanol + gasoline is extremely complex but the result is the CO carbon monoxide does not immediately convert to CO2 only when all the gasoline in the charge has finished burning does the ethanol burn and convert all CO to CO2 and it burns much faster causing pressure spikes in the cylinders. That alone does not cause worn bearings but ethanol also dilutes the oil and has a corrosive effect on bearings. Galvanisation or aluminium alloys to protect against corrosion does not stop or prevent corrosion it only slows it down.

Bearing corrosion by ethanol diluted in the oil + sudden high pressures in the cylinders due to fast ethanol burning after all the gasoline charge has burned (which the cooling presence of ethanol slows down) is what causes bearing to wear faster. The oil lubricity power is broken by ethanol. High RPM dilutes the oil faster with ethanol. Bearing corrosion can not be detected by Blackstone oil analysis as they use a spectroscopy method which only detects the levels of each elements not molecules.

Using ethanol free gasoline basically suppresses all risks of premature bearing wear.

Not going to dispute this because I really couldn't tell you, but what I will say from observation is why is this issue only prevalent with BMWs NA M high revving motors? Shouldn't this be across the board along with other manufacturers?

[Helmsman]

Interesting input Joe.
In Sweden we have a 5% ethanol mix as it seems regardless of supplier and octane.
- What's the number in the US?

We only have around 500 E9x' over here, I've heard about at least a couple of engine brake downs due to bearing so obviously happens here as well but it seems very rare.

[IMG]

Originally Posted by JRV

Got them swapped yesterday thanks to IMG and Corry. Using OEM rod bolts and AMSOIL 5w-50. So far haven't noticed much except a little smoother probably due to oil change. Motor has 49,750k miles, never tracked. It's always driven lightly until full warmed up and even then all I really do is cruise at about 4-4.5 with occasional whomping going on freeway. Oil changes after 16k miles were done anywhere between 3k-7k miles.
Anyway, I don't think they should look like this. I'm glad I did them, now feeling more eat ease. What do you guys think of these?

Thank you and glad all went well !

[IMG]

Originally Posted by rcracin

Nice! Corry and Izzy ftw

[rcracin]

I'm sitting here laughing at how this dude arrived at a little ethanol being the cause of rod bearing wear. I'll remind all my friends running e85 to change their bearings after every tank of gas because the ethanol mixes with their oil and wears out their bearings.

We should inform blackstone about the issue so they test our oil samples for ethanol content. Thank you for this wonderful discovery!

[Sneaky Pete]

But not in the same league of hilarious as three dudes with no experience of rod bearing design thinking they can come up with a better design than the BMW M division.

[JRV]

Originally Posted by Sneaky Pete

But not in the same league of hilarious as three dudes with no experience of rod bearing design thinking they can come up with a better design than the BMW M division.

...you think it's just 3 dudes on this? Maybe if you actually read up on who helped develop this along with the "3 dudes" you wouldn't try that BS.

[rcracin]

Pure comedy. The design is the same as oem. Wanna know how? It's the same manufacturer. Just a little more clearance added. Not rocket science. Just a lot of experience and testing.

[L4ces]

Hey Sneaky Pete, you just joined and have 1 post.

Like to hear more on the bearing issue. What is your take on it and why?

[serranot]

Originally Posted by JRV

Not going to dispute this because I really couldn't tell you, but what I will say from observation is why is this issue only prevalent with BMWs NA M high revving motors? Shouldn't this be across the board along with other manufacturers?

+1. "Joe" has some interesting comments, from the amazing performance difference without ethanol to this. Sorry, but I don't buy it. Eliminating ethanol will *not* solve a bearing clearance issue if you have one.

[m3aviator]

Originally Posted by JoeM3SSII

What i think... back when ethanol was not powering combustion engines the oil industry had to make much better refined gasoline because MBTE and before that lead were poor octane boosters. Now they rely so much on ethanol to boost octane level their base mix is much poorer quality which reduces refinery costs and boosts profit too. No problem because modern engine DME can compensate for fuel right ? Yes but that's a simplified view of a much larger problem. Ethanol completely changes the combustion reaction, it is an oxygenate and it has an hydroxyde OH group that gasoline does not have. What happens in the combustion chamber with ethanol + gasoline is extremely complex but the result is the CO carbon monoxide does not immediately convert to CO2 only when all the gasoline in the charge has finished burning does the ethanol burn and convert all CO to CO2 and it burns much faster causing pressure spikes in the cylinders. That alone does not cause worn bearings but ethanol also dilutes the oil and has a corrosive effect on bearings. Galvanisation or aluminium alloys to protect against corrosion does not stop or prevent corrosion it only slows it down.

Bearing corrosion by ethanol diluted in the oil + sudden high pressures in the cylinders due to fast ethanol burning after all the gasoline charge has burned (which the cooling presence of ethanol slows down) is what causes bearing to wear faster. The oil lubricity power is broken by ethanol. High RPM dilutes the oil faster with ethanol. Bearing corrosion can not be detected by Blackstone oil analysis as they use a spectroscopy method which only detects the levels of each elements not molecules.

Using ethanol free gasoline basically suppresses all risks of premature bearing wear.

Jesus where do you come up with this crap? And people really believe it too. Gee metal rubs off when it comes in contact with other metal.

You can't fix the problem with bearings. This is just more marketing bs. The crank has to come out of the car to fix the problem.

Wait let me sell you some bearings at a real good price.

[OM VT3]

Originally Posted by rcracin

Pure comedy. The design is the same as oem. Wanna know how? It's the same manufacturer. Just a little more clearance added. Not rocket science. Just a lot of experience and testing.

Actually clearance is very different at 90 degree angle

[OM VT3]

Originally Posted by m3aviator

Jesus where do you come up with this crap? And people really believe it too. Gee metal rubs off when it comes in contact with other metal.

You can't fix the problem with bearings. This is just more marketing bs. The crank has to come out of the car to fix the problem.

Wait let me sell you some bearings at a real good price.

Please tell me why the crank needs to come out?

If the bearings add clearance then whats the reason the crank should come out?

[m3aviator]

Originally Posted by OM VT3

Please tell me why the crank needs to come out?

If the bearings add clearance then whats the reason the crank should come out?

Slap bearings in with out measuring anything? Rod ecc, rod stretch, journal diameter? Etc? You really think this is one size fits all? Every crank is the same? Every rod/main journal ?

This is all marketing nonsense. If at all anything put stock bearings back in, with stock bolts. Years of discussion and yet not a single engineer or anyone with inside knowledge has made a single post. Every single comment is pure speculation. The owners of this forum are in bed with the manufacturer. We know nothing for a reason.