Z4M Supercharged Engine and Transmission Build

[gmd2003]

Hey guys as some of you know I have done a lot of modifications to my ESS supercharged car to make it more track worthy over the past several years. I had recently figured out I needed bigger injectors,a bigger oil cooler over the 525 one, and more radiator. After getting the engine sorted I refocused on the chassis and installed a cage and chassis reinforcement with MCS 2 ways for my suspension. Unfortunately, on my first outing with the new cage and suspension after setting a new street tire PB my motor went. Turns out the bolts to my vibration damper sheared off at 150mph and the resulting vibrations took off all my belts , lost cooling, power steering , and alternator going into turn 1 at 150 mpg GPS . Internally the bearings (rod and mains took a beating, the intake cam bolts backed out , the timing chain became loose , and the crank was heavily scarred. The following pics show the carnage well. You can clearly see where the timing chain was moving around and dug into the oil pick up. Interestingly the motorsport bearings used did not show increasing lead on an oil analysis and appears to not contain lead. So for the newer replacement bearings it looks like we can not count on that. I'd say most of the damage was acute in this case however.

















So the end result is I am moving forward with a full rebuild, with the goal being reliability not peak power. I am doing the following build with Andrew Lang of Lang racing development.

1.) Mahle Power pack pistons stock compression ratio, stronger and slightly lighter than stock.

2.)Custom spec H type Carrillo rods, able to hold 650hp yet slightly lighter than stock and accept the wider rod bearing used for my build.

3.) Carrillo pins

4.) Stage 3 head work for SC application

5.) Modified crank to accept a wider rod bearing ( correction of the stock weakness of the S54. You can read more about this on Lang Racing Developments website.

6.) Iconel valves for better heat management.

7.) Upgraded valve springs since i spend a lot of time at redline.

8.) VAC modified OEM oil pump.

9.) Everything else for the rebuild will be OEM per Andrew's recs.

Transmission /clutch.
1.) I am getting the transmission rebuilt with REM polished internals by Dan Fitzgerald of Diffsonline. This will greatly improve shifting speed as it was pretty worn and getting very notchy at redline. Also should slightly reduce drivetrain losses .

2.) After my bad light weight flywheel vibration issue which i believe set events in motion for this failure I am going with a new Dual mass flywheel.

3.) I was able to procure from Sachs Motorsport Germany , a SACHS racing clutch that was designed for the stock dual mass ! It holds an extra 100 NM over the stock clutch and is the only option that was made to work with the OEM dual mass.

Its a ton of work but I am very excited to get everything put back to together. Feel free to ask any questions and i will update with build photos as they come in to me.

Cheers
G

[dorifto88]

for the life of me i cannot imagine that the bolts came off =/

[gmd2003]

Originally Posted by dorifto88

for the life of me i cannot imagine that the bolts came off =/

Several of the bolts that held the vibration damper in place sheared off. This is the session before the failure . It was totally fine until it wasn't . Crazy stuff.

[ZStig]

very sorry to hear about your troubles. Its the first engine failure I've seen on the ESS kit. Of course yours is also the most tracked car, so that doesn't help.

Really interested in the clutch upgrade, do you have a part number?

Looking forward to hearing your feedback about the trans rebuild too

[seank]

Good luck George. I just got my s14 back from being rebuilt. It happens eventually over time if you are driving her hard. All you can do is minimize. Andrew can help with that.

[Beedub]

Originally Posted by ZStig

very sorry to hear about your troubles. Its the first engine failure I've seen on the ESS kit. Of course yours is also the most tracked car, so that doesn't help.

Really interested in the clutch upgrade, do you have a part number?

Looking forward to hearing your feedback about the trans rebuild too

From what I'm reading the S/C wasn't the cause of the engine failure??

OP great to see you back as always.

[GuidoK]

I am confused; which bolts broke?
In the lower pic: the bolts 8 or bolts 6:


I always thought this would be a stronger system (with the multiple bolts) than the normal type of vibration damper with large central bolt (what for example the m54 has):



I even thought of once converting to the s54 type vibration damper (the s52 has a similar system that probably bolts onto the m54 (same crank))

[tikamak]

Originally Posted by gmd2003

Hey guys as some of you know I have done a lot of modifications to my ESS supercharged car to make it more track worthy over the past several years. I had recently figured out I needed bigger injectors,a bigger oil cooler over the 525 one, and more radiator. After getting the engine sorted I refocused on the chassis and installed a cage and chassis reinforcement with MCS 2 ways for my suspension. Unfortunately, on my first outing with the new cage and suspension after setting a new street tire PB my motor went. Turns out the bolts to my vibration damper sheared off at 150mph and the resulting vibrations took off all my belts , lost cooling, power steering , and alternator going into turn 1 at 150 mpg GPS . Internally the bearings (rod and mains took a beating, the intake cam bolts backed out , the timing chain became loose , and the crank was heavily scarred. The following pics show the carnage well. You can clearly see where the timing chain was moving around and dug into the oil pick up. Interestingly the motorsport bearings used did not show increasing lead on an oil analysis and appears to not contain lead. So for the newer replacement bearings it looks like we can not count on that. I'd say most of the damage was acute in this case however.

So the end result is I am moving forward with a full rebuild, with the goal being reliability not peak power. I am doing the following build with Andrew Lang of Lang racing development.

1.) Mahle Power pack pistons stock compression ratio, stronger and slightly lighter than stock.

2.)Custom spec H type Carrillo rods, able to hold 650hp yet slightly lighter than stock and accept the wider rod bearing used for my build.

3.) Carrillo pins

4.) Stage 3 head work for SC application

5.) Modified crank to accept a wider rod bearing ( correction of the stock weakness of the S54. You can read more about this on Lang Racing Developments website.

6.) Iconel valves for better heat management.

7.) Upgraded valve springs since i spend a lot of time at redline.

8.) VAC modified OEM oil pump.

9.) Everything else for the rebuild will be OEM per Andrew's recs.

Transmission /clutch.
1.) I am getting the transmission rebuilt with REM polished internals by Dan Fitzgerald of Diffsonline. This will greatly improve shifting speed as it was pretty worn and getting very notchy at redline. Also should slightly reduce drivetrain losses .

2.) After my bad light weight flywheel vibration issue which i believe set events in motion for this failure I am going with a new Dual mass flywheel.

3.) I was able to procure from Sachs Motorsport Germany , a SACHS racing clutch that was designed for the stock dual mass ! It holds an extra 100 NM over the stock clutch and is the only option that was made to work with the OEM dual mass.

Its a ton of work but I am very excited to get everything put back to together. Feel free to ask any questions and i will update with build photos as they come in to me.

Cheers
G

I rebuilt my engine before what happened to you happens to me as part of my engine bulletproofing:

• extra 20% oil flow VAC OEM oil pump
• C300 vanos exhaust hub
• Dr. vanos noise reduction full kit
• 10.9 grade Vanos bolts
• WPC Rod Bearings
• ARP head studs ARP2000
• ARP rod bolts
• And everything else OEM (gasket kits and such)

I also found that the 10w-60 Castrol is too thick for my spirited driving even in 30 degrees Celsius summers so i switched to Mobil1 0W-40. I think you should do the same after installing the greater flow oil pump, especially with the bigger oil cooler and more efficient radiator.
Here are my rod bearings with Castrol TWS 10w-60 and 40K miles of spirited street driving.



I was amazed that with your tracking the engine lasted that long with a supercharger. Normally the NA S54 have the same problems when tracked like you do, It seems to me that the supercharger did not shorten its life one bit.

[tikamak]

Oh I forgot to mention that I did a compression test and i have 185 psi across all cylinders so i did not bother with the pistons and connecting rods.

I also changed the main bearings to a new OEM set (glyco) because they looked like the rod bearings and needed changing as well. i figure i won't be having this problem with the pump and different oil weight.

[gmd2003]

Originally Posted by ZStig

very sorry to hear about your troubles. Its the first engine failure I've seen on the ESS kit. Of course yours is also the most tracked car, so that doesn't help.

Really interested in the clutch upgrade, do you have a part number?

Looking forward to hearing your feedback about the trans rebuild too

Here is the link to the Sachs performance site, i ordered the complete kit which consists of the performance clutch and rigid performance disc. Its still an organic friction material but it can hold 540 nm of tq. http://www.sachsperformance.com/Sach..._496_4401.html

[gmd2003]

Originally Posted by seank

Good luck George. I just got my s14 back from being rebuilt. It happens eventually over time if you are driving her hard. All you can do is minimize. Andrew can help with that.

Thanks man , I know it will be better than before , it just sucks it happened on my first weekend with the new suspension and chassis reinforcement. I was picking up time FAST. MCS 2 ways are incredible especially the conversion to the rear coilover.

[gmd2003]

Originally Posted by Beedub

From what I'm reading the S/C wasn't the cause of the engine failure??

OP great to see you back as always.

This was prolonged a high rpm use failure with a vibrational component. The only thing that makes sense to me is the damper failed then caused severe vibration resulting in the sheared bolts on the damper and the backing out of the cam bolts. Almost all of the bearing wear was acute due to the crank moving around once the damper was toast. I had replaced the rod bearings less than 15k miles ago, and the Vanos system was rebuilt 5k ago. The crazy thing is the vibration damper only had 5k miles on it as it was replaced when I rebuilt the VANOS. I did have the unbalanced lightweight flywheel debacle at the same time as the vanos work and the vibrations with that likely set off this failure. If the vibrations were bad enough to destroy a SACHS HD clutch backing plate then .... Thats why i'm sticking to a new stock dual mass this time. I don't think the supercharger had anything to do with this failure.

[gmd2003]

Originally Posted by GuidoK

I am confused; which bolts broke?
In the lower pic: the bolts 8 or bolts 6:


I always thought this would be a stronger system (with the multiple bolts) than the normal type of vibration damper with large central bolt (what for example the m54 has):



I even thought of once converting to the s54 type vibration damper (the s52 has a similar system that probably bolts onto the m54 (same crank))

Yep the #8's were sheared off but the damper was also split in two. Not sure what happened first, but I would assume it was the damper that failed first.

[Beedub]

while your in their get the ATI damper, its expensive but a very nice piece!

[gmd2003]

Originally Posted by tikamak

I rebuilt my engine before what happened to you happens to me as part of my engine bulletproofing:

• extra 20% oil flow VAC OEM oil pump
• C300 vanos exhaust hub
• Dr. vanos noise reduction full kit
• 10.9 grade Vanos bolts
• WPC Rod Bearings
• ARP head studs ARP2000
• ARP rod bolts
• And everything else OEM (gasket kits and such)

I also found that the 10w-60 Castrol is too thick for my spirited driving even in 30 degrees Celsius summers so i switched to Mobil1 0W-40. I think you should do the same after installing the greater flow oil pump, especially with the bigger oil cooler and more efficient radiator.
Here are my rod bearings with Castrol TWS 10w-60 and 40K miles of spirited street driving.



I was amazed that with your tracking the engine lasted that long with a supercharger. Normally the NA S54 have the same problems when tracked like you do, It seems to me that the supercharger did not shorten its life one bit.

The problem is the rod bearing design which is why I went with my engine builders approach of using a larger bearing and regrinding the crank. As far as oil viscosity you need to pick it according to bearing clearance, rpm use of the motor and operating temperature.Our motors with a relatively "loose clearance" and narrow bearings requires a higher viscosity oil to maintain film strength at high temps and rpms. At high temperatures and rpms the last thing you want is thinner oil as the film strength will break down and you will have increased wear. On track I see sustained oil temperatures over 250 degrees so 0-40 would literally turn to water. I have been using Motul V-spec 15w-50 and was very pleased with its stability (its viscosity did not decrease over time like the Castrol 10-60 and my engine wear during its use was excellent despite HARD use. It also has one of the stoutest additive packages of any oil available and is a true Gen V ester . I have never seen oil look so good after a track day. Honestly the increased flow of the VAC oil pump may help keep oil pressure up at high temps but it will have no effect on the bearing oil film stability. I had to replace my pump bc of damage so I went ahead with it. How does the 0-40 look on oil analysis?

[pokeybritches]

There's a theory floating around out there, at least on the S65 side, that the bearing issue may be related to the bolt torque. Engines with as little as 6k miles are showing significant rod bearing wear with the OEM stretch bolts, but with ARP bolts and VAC coated bearings, the same engine showed no wear after another 33k supercharged miles. It's worth a look.

Intreresting to hear about the vibration damper. How many track miles are on the car again?

[Finnegan]

Originally Posted by pokeybritches

There's a theory floating around out there, at least on the S65 side, that the bearing issue may be related to the bolt torque. Engines with as little as 6k miles are showing significant rod bearing wear with the OEM stretch bolts, but with ARP bolts and VAC coated bearings, the same engine showed no wear after another 33k supercharged miles. It's worth a look.

Intreresting to hear about the vibration damper. How many track miles are on the car again?

Very interesting indeed!

[StickMon]

I got a little concerned after seeing threads about split dampers.
After some research I found that most or all were from users of lightweight flywheels.
Even if it's balanced, some of the work that would have been done by the flywheel gets transferred to the damper.
If the flywheel was unbalanced, there's your root cause.
Best of luck with the repairs.

[pokeybritches]

Originally Posted by Finnegan

Very interesting indeed!

Here you go: http://www.m3post.com/forums/showthread.php?t=1073979

[inTgr8r]

+1
thanks for the info!

[gmd2003]

Originally Posted by pokeybritches

There's a theory floating around out there, at least on the S65 side, that the bearing issue may be related to the bolt torque. Engines with as little as 6k miles are showing significant rod bearing wear with the OEM stretch bolts, but with ARP bolts and VAC coated bearings, the same engine showed no wear after another 33k supercharged miles. It's worth a look.

Intreresting to hear about the vibration damper. How many track miles are on the car again?

I used ARP rod bolts when I did my bearing change 15k ago . I'm at 79k with lots of track miles -100 track days . I 100% think the flywheel triggered the failure of the damper . The rod bearing design on the s54/S65/S85 is their only real weakness . Just too damn narrow for >8k rpm's .

[Beedub]

tbh the damper on these cars is a known failure point.... they dry out and fail leaving engine damaging vibrations behind.... the ATI fluid filled unit stops the issue!!