Engine Failure @ 14k miles

[tdott]

Sounds like a bad rebuild, I wouldn't speculate more until the motor is torn down.

Also 14k miles on a rebuilt motor, is not the same as 14k miles on an original motor.

[charliev68]

For sure keeping the same pistons sounds like a bad rebuild because it calls into question a lot of other things that any rebuilder would know. First off, spinning a main usually means a cracked or at least a highly compromised block. Anyways, proof is in the pudding, engine took a dump.

[SYT_Shadow]

Originally Posted by tdott

Also 14k miles on a rebuilt motor, is not the same as 14k miles on an original motor.

This. Title is misleading.

Choose wisely when getting a rebuild, half the time the remedy is worse than the disease

[former 240 s14]

Originally Posted by charliev68

For sure keeping the same pistons sounds like a bad rebuild because it calls into question a lot of other things that any rebuilder would know. First off, spinning a main usually means a cracked or at least a highly compromised block. Anyways, proof is in the pudding, engine took a dump.

I was not the owner when the main bearing went so I can't speak to the conversations that happened at that time. After the main bearing went a new donor motor was purchased with 60k miles on it and was went through with the build list that is communicated on my first post.

Hoping THIS motor (which is the rebuilt motor) has only a spun rod bearing. It shut off immediately on its on but started back up for 5 seconds when I turned it off again.

Rubin

[DrFerry]

Originally Posted by former 240 s14

I was not the owner when the main bearing went so I can't speak to the conversations that happened at that time. After the main bearing went a new donor motor was purchased with 60k miles on it and was went through with the build list that is communicated on my first post.

Hoping THIS motor (which is the rebuilt motor) has only a spun rod bearing. It shut off immediately on its on but started back up for 5 seconds when I turned it off again.

Rubin

I'm hoping your situation is just a spun bearing due to oil starvation, crud in the crank galleries, or a combination of both. There are bona-fide dry sump kits out there for the S65, but your Accusump idea maybe the most cost efficient for peace of mind for future track events. Please let us know the root cause when you know. PS: The S65 OEM sump baffles, dual oil pickup and dual 'wing' design has successfully allowed many forum members to participate in HPDE and Pro-Solo track events, so something is definitely up with the failure circumstances you unfortunately experienced. Good luck with the Sherlock Holmes part of the failure analysis and investigation.
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https://www.m3post.com/forums/showthread.php?t=392485
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https://www.cantonracingproducts.com/accusump
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[former 240 s14]

Small update:

I have got the engine out and on an engine stand now. Had just enough time to pop off the oil pan to quickly inspect before having to stop for the weekend. Definite heat issues at the front of the engine on the ROD caps for Cylinders 1 & 5. We pulled the bearings for Cyl 5 and this is the result. Unbelievable the carnage given the motor had a near perfect oil analysis before the event. The heat is leading me to believe it was oil starvation but more inpsection obviously needs to be done.

More to come but wanted to share the results thus far. So far I have a new used crank, oil pan, AAF pan baffles, oil diverter kit, Mahle Motorsports Forged Pistons, and Bimmerworld Oil Dipstick kit on order. Plan is to break down the engine and send the short block to Ben at Rogue Engineering. I don't trust anyone more and am super thankful he is willing to jump in on this project. He already has my extra crank and is measuring out the journals to ensure proper bearing clearance with the new ACL bearings. We may also machine the upper bearing on the Main Bearing 1 to help with the extra stress that bearing gets on most S65's.

Lot's more to come, this week I'll be tearing down the engine and inspecting the rest of the rod caps/bearings before preping the motor to be shipped to Ben.

[omgzirra_exe]

personally just my opinion if cost allow.

I would 100% WPC the entire rotating assembly, main bearings if you are sticking with standard clearance or even extra clearance, rod bearings, the pistons, the rings, etc.

Cyrogenic treating the block should also help as with longevity.

[former 240 s14]

Tear Down Update:

The tear down is done. It took four days to get the engine out of the car and get to the short block. Now it's off to Rogue Engineering to do some work.

Failure Hypothesis: Road America is brutal on oil systems. From what I can deduce is that the engine oil starved multiple times during my warm up laps (5 total). Each time this happened the front cylinder (5&1) rods and crank became super hot. When the oil would flow back the heat from the RODs would pressurize the oil out the front main seal. This section of ROD's so huge color change versus the rest of the engine. With this repeating up to 15 times (true number not known) it emptied the pan of oil and caused the bearing to spin.

Additional Note: This vehicle has had 3 engines with 3 different drivers. Each engine has experienced rod bearing/main bearing failure. The only common denominator is it had the same engine builder for all 3 engines (performing at a minimum rod bearing service.) During the tear down I found inconsistencies I would not expect from a reputable shop. These included....

1. Breakaway Torque values ranging from 35(ish) ft lbs to 45 ft lbs on rod bolts.
2. Un-torqued oil pan bolts
3. Stripped bolts
4. Motor mounts finger tight
5. Failure to consistently lube EVERY rod bolt. 2 of the 16 had zero assembly lube.
6. Potentially misclocked vanos gears

I am waiting to say the name of the shop still as Rogue needs to inspect the main bearings. I want the tear down to be completed before I potentially affect the reputation of a shop.

Learnings these past few weeks:

I have learned a metric ton of information about the S65 and BMW's decision making to compromise the construction of this engine to make it a better street friendly setup. At the end of the day the weekpoint of this engine has always been bearing support, however a few items are really worth noting.....

1. Oil Temp -
Higher Oil Temps are fine for street use. You don't stay in the high rev ranges like you do in track. With the increased temp the lower the viscosity of oil. This affects oil volume flow rate, especially as RPM's increase to redline. Keeping oil temp in the low 200's is ideal for viscosity. We are talking 220ish.

2. Oil Flow -
Oil flow rate is more important than oil pressure, as oil pressure is a direct result of oil flow. The OEM oil pump has trouble keeping oil flow at desired ranges the higher the engine revs.

3. Bearing Clearance -
Tight bearings are fine for street use and help keep oil flow strong at lower RPM's. Unfortunately when you track your M3 as hard as we do these bearings are counterproductive for oil flow at high RPM's. BMW figured this out for the bearing changes but never went far enough.

My Fix:

Ideally I would be running a dry sump system, but I unfortunately don't have $10k laying around in my couch. So with this I decided on the following:

1. Rogue Engineering is now selling SRD S65 Oil Pump Gearing - These gears utilize the OEM gear pump chain and overdrive the pump +21%. There is a 15 page engineering brief on these gears and their development, you gotta read this yourself!
2. Epic Motorsports Oil Diverter Kit - although this negatively impacts street driving it's a must for aggressive track weekends
3. AAF Oil Pan baffles & BW Dipstick Kit
4. Custom machined OEM crank to be matched with ACL Race Bearings - Rogue is doing the measurements of my crank with the physical bearings I will be running.
5. Accusump - this system has been proven to help with oil volume during oil starvation situatons.
6. Epic Tune - Will have this tuned by EPIC and I will be LOWERING RPMS to 8000-8100.
7. Potential relocation of Oil Cooler to trunk - This helps weight obviously, makes the accusump install much easier, and keep the cooler away from the hot engine. I am going to run a fan and have a section of the trunk cut out for flow.

Here are the links to the parts I am going with that I have figured out thus far, let me know your thoughts and please keep it constructive lol!

Rubin

SRD Oil Pump Gears: https://www.rogueengineering.com/SRD...et_p_2518.html

AAF Baffle Kit: https://advancedautofab.com/p/aaf-s6...-w-aaf-baffle/

BW Diptsick Kit: https://www.bimmerworld.com/S65-Oil-...Parts-Kit.html

Epic Motorsports Oil Diverter Valve Kit: https://www.bimmerworld.com/Epic-Mot...it-E9X-M3.html

Accusump Kit: https://www.pegasusautoracing.com/pr...p?Product=1241

[spammysammich]

Do you happen to know if the most recent build started with a known good block that had no cracking at the #1 main bearing journal? There have been several reported cases of cracks propagating up to the oil galley. It is conceivable that a rebuilt block may have been cracked to begin with, leading to reduced flow to main 1 and the 1/5 rods.

[DrFerry]

Brintech video about the S65 main bearing block cracking…
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[former 240 s14]

Originally Posted by spammysammich

Do you happen to know if the most recent build started with a known good block that had no cracking at the #1 main bearing journal? There have been several reported cases of cracks propagating up to the oil galley. It is conceivable that a rebuilt block may have been cracked to begin with, leading to reduced flow to main 1 and the 1/5 rods.

Should of mentioned this above, apologies. Engine core was a good one with 60k miles. New OEM Main's were installed when the rebuild happened 14k miles ago.

I am going to be talking with the engine builder about machining extra clearance the top bearing in Main Cap 1. This is recommended by a good engine builder in England. See video above from Dr. Ferry!

Thanks for the feedback!

Rubin

[former 240 s14]

Originally Posted by DrFerry

Brintech video about the S65 main bearing block cracking…
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Oops you beat me to it! I am following their advice on mains as well!

Rubin

[rcracin]

I thought oil starvation would affect the bearings furthest from the pump, not the closest. Be interesting to see the mains.

[spammysammich]

Chris at Partee had mentioned that just the act of bolting on the crank pulley expands the front of the crank enough to reduce the clearance of the first main. Lots of subtle things add up to an unfavorable stacking of tolerances

[kolosy]

Isn’t there a pretty large contingent of track rats with stock oil delivery systems? You’re in the position to make these upgrade so that’s a great silver lining, but feels like the fault is much more with the engine builder than the design.

[Brandoch]

Originally Posted by spammysammich

Chris at Partee had mentioned that just the act of bolting on the crank pulley expands the front of the crank enough to reduce the clearance of the first main. Lots of subtle things add up to an unfavorable stacking of tolerances

It's definitely a challenging diagnosis.
-Bearing clearance too tight
-Super thick oil
-Long crank snout
-2 double timing chains
-2 serpentine belts
-4 bolts on the front of the snout for the crank pulley
-8400 RPM

[former 240 s14]

Originally Posted by rcracin

I thought oil starvation would affect the bearings furthest from the pump, not the closest. Be interesting to see the mains.

Main's will be pulled at Rogue. Definitely need to do them while I am there.

[former 240 s14]

Originally Posted by kolosy

Isn’t there a pretty large contingent of track rats with stock oil delivery systems? You’re in the position to make these upgrade so that’s a great silver lining, but feels like the fault is much more with the engine builder than the design.

You are not wrong and I don't disagree about the track rats out there. Considering this is the 3rd engine failure from the same shop in this car with 3 different drivers I would tend to agree with you that the build quality contributed to the failure. This is the only common denominator but it's very difficult to pin everything entirely on them, and I genuinely believe there were other factors at play too.

All I can do is try to prepare for worst case scenario (as it seems to follow me anywhere I go, lol.) I am lucky to have a good support structure and will keep us all updated as I go through this process.

Hopefully others can learn from my misfortunate. The biggest thing I see is during a rod bearing job throw in the oil pump gears. They are $400 from Rogue and worth it.

Rubin

[tdott]

Originally Posted by former 240 s14

Considering this is the 3rd engine failure from the same shop in this car with 3 different drivers I would tend to agree with you that the build quality contributed to the failure.

Was the complete oil system replaced during any of these rebuilds? (Cooler, Lines, OFH, vanos, etc). Any thing that was not torn down and cleaned, or replaced will have oil debris in it which gets into the new engine and causes a failure. Deansbimmer has mention this several times, shops failing to replace and/or ensure a clean oil system has caused failures of the rebuilt engine.

Also without checking the #1 Main Bearing, your above failure analysis is premature. A torn up main bearing will cause what you are seeing and falsely assuming is oil starvation due to the oil system design, when it's really oil starvation due to the main bearing issue causing a downstream effect.

Let's see some proof before you make the claim of "OEM oil pump has trouble keeping oil flow" or any other baseless claim.

Originally Posted by former 240 s14

1. Oil Temp -
Higher Oil Temps are fine for street use. You don't stay in the high rev ranges like you do in track. With the increased temp the lower the viscosity of oil. This affects oil volume flow rate, especially as RPM's increase to redline. Keeping oil temp in the low 200's is ideal for viscosity. We are talking 220ish.

There is no evidence of this, lets see some logs or some type of data before making baseless accusations. Good luck at trying to keep an S65 oil temps at 220 on track. Lookup HTHS values for oils, look up what oil manufactures rate their oils at before they start to degrade, look up testing and reviews done on oils. 220 is nothing for a high quality synthetic oil.

Originally Posted by former 240 s14

2. Oil Flow -
Oil flow rate is more important than oil pressure, as oil pressure is a direct result of oil flow. The OEM oil pump has trouble keeping oil flow at desired ranges the higher the engine revs.

I fear you are repeating the RE marketing BS, there is no evidence of "OEM oil pump has trouble keeping oil flow" in fact the data shows the opposite.

It's a variable pressure oil pump with a pressure relief, and those guys think over driving it is a good idea.

[former 240 s14]

Originally Posted by tdott

I fear you are repeating the RE marketing BS, there is no evidence of "OEM oil pump has trouble keeping oil flow" in fact the data shows the opposite.

It's a variable pressure oil pump with a pressure relief, and those guys think over driving it is a good idea.

The brief that talks about the oil pump gears is not from Rogue. It's from the manufacturer of the gear kit. It's also an engineering brief, which talks about all the issues you bring up in your points.

Before we go back and forth first try reading it. My father, who was an aerospace engineer, appreciated the detail and write up. Not saying he is the end all be all, but he has more experience in engineer briefs than I have.

Rubin

[spammysammich]

tdott brings up a good point. I've seen a main bearing spun to the point where the oil passage on the bearing itself was smeared shut preventing oil ingress altogether to the journal, starving it of oil.

[former 240 s14]

Originally Posted by spammysammich

tdott brings up a good point. I've seen a main bearing spun to the point where the oil passage on the bearing itself was smeared shut preventing oil ingress altogether to the journal, starving it of oil.

Main bearing failure is a great point, we'll know if its the case here soon enough. Given the main bearings being new and having 14k miles on them the probability they were the culprit is small IMO, but still could be the case.

Rubin