s54 harmonic balancer failure

[jason89i]

I spoke with Bimmerworld...... nothing available.
VAC has a prototype ATI unit that should be for sale next week. No pricing yet.

I sprung for a used one ('05 45k mi.) just to get be back on track for this season. Also picked up some 3" blower motors to point a 3" duct. Fingers crossed for the rest of the season.

Cheers, Jason

[jason89i]

I found a good balancer, replaced it, much better. However I still get an occasional VERY slight vibration. Not sure if its my brain playing tricks or if the bearings got cooked. I am getting ready to run a compression test and pull the pan to check the bearings.

Any insight?

cheers, jason

[jonmacs22]

No one can give you any real insight of value without tearing apart your motor; there are simply too many variables.

[Mike S]

If it's legal in your class, you might want to check out these:

http://store.bimmerworld.com/s54-rod...kit-p1020.aspx

Mike

[jason89i]

No one can give you any real insight of value without tearing apart your motor; there are simply too many variables.

not looking for a "value" of the motor. Im looking for insight as to what else could have been damaged from the vibration.

someone did mention that the clutch / flywheel vibrated loose when their balancer went south. I am pulling it apart (hopefully tonight) and wanted insight on specific areas to double check.

cheers, jason

[Gt4]

The harmonic balancer melted/splitted on my track car last summer while downshifting from 5-4-3. I changed the disc but the belt was shaking and a rattling noise was coming from the block... I was sure the rods bearing were gone and the crank was bent.

I removed the engine from the car and removed the oil pan. The noise was coming from a loosse chain tensionner stud ... And the crank was OK, it was just the crank pulley that was off. But I had already bought another engine so I never tried it back on the track.

[PSangavaramM3]

can anyone provide the oem part #?

[GGray]

The main reason the jap stuff lasts longer is Germany REQUIRES a certain percentage of recycled rubber/plastic/steel. One reason the plastic OEM radiators fail so fast. Virgin rubber, plastic, and steel are much more durable..

tidbit of info I found intresting... Kia and Huyndai use 100% virgin steel in their cars. Supposedly they are the only large auto company still doing it. They also own all the companies producing parts for their cars minus tires and stero/nav ssytems...

I planned on doing the bearings in my S54 that just got dropped off for my E36 no roofer stret/track toy. Sounds like I need to stick a new harmonice damper on it while its still out.. Looking for reliabliity with the S54.

[bawareca]

The main reason the jap stuff lasts longer is Germany REQUIRES a certain percentage of recycled rubber/plastic/steel. One reason the plastic OEM radiators fail so fast. Virgin rubber, plastic, and steel are much more durable..

.................

I hope you dont mean that the Jap or Korean steel is better or lasts longer than the German.
In winter European countries the japaneese cars last for 5-8 winters,that is.

[gretzky]

OP,

I had the same failure a couple of years ago and did a similar search on solutions. The short answer is to use the stock damper and replace it every 3 years if its an HPDE car, every year if its a racer. The only permanent solution is to use a viscuous damper, but I have had no luck finding one. I would stay away from an aftermarket part as this is a highly tuned piece.

The after effect of losing the damper was that my motor spun the nut off the oil pump amd shattered some timing chain guides about 6 months later. I have to assume this was a result of the vibration my engine experienced. We tore the motor down, amd the internals were in excellent condition, even after 100k mi and hard use.

I hope this helps.

Kirk

[M3 Euro LTW]

OK...

This product has been out for a while. Someone must be using it in the forum.

Any first hand experience? Can not imagine there are none out there in use.

I'm about to drop an S54 into the car, bearings and rods are taken care of, this seems to be an issue.... so hard to believe no one has plopped down their money and has some first hand knowledge this late in the game.

[sublimeM3]

Thoughts on replacing the stock balancer for a new stock part? DD/hpde/autox toy
135k mi $800+ is going to be hard to hide from the wife

[J Smith]

OK...

This product has been out for a while. Someone must be using it in the forum.

Any first hand experience? Can not imagine there are none out there in use.

I'm about to drop an S54 into the car, bearings and rods are taken care of, this seems to be an issue.... so hard to believe no one has plopped down their money and has some first hand knowledge this late in the game.

I've been running the ATI damper all year. No issues or anything special to report.

[Greg S]

OK...

This product has been out for a while. Someone must be using it in the forum.

Any first hand experience? Can not imagine there are none out there in use.

I'm about to drop an S54 into the car, bearings and rods are taken care of, this seems to be an issue.... so hard to believe no one has plopped down their money and has some first hand knowledge this late in the game.

I'll be installing one next week, I've been waiting on a crank holder tool from Germany. You could probably install it without it, but it's nice having the right tool. FYI, the ATI damper uses torx PLUS bolts, not regular torx, so pick up a set of those if you don't already have them. I also had the AC pulley machined off since VAC doesn't offer that particular option with a standard sized crank pulley.

[Mike S]

It isn't compatible with the stock bolts? I'll have to return the new set if that's the case...

[Greg S]

It isn't compatible with the stock bolts? I'll have to return the new set if that's the case...

I'm talking about the bolts on the damper itself, not the ones securing it to the crank.

[Mike S]

I just looked at mine in the box. I must be slow tonight - I'm missing your point. The torx bolts on the damper don't look like they're anything we service. They appear to hold the component pieces together.

When does one remove / replace those bolts?

Mike

[Greg S]

I just looked at mine in the box. I must be slow tonight - I'm missing your point. The torx bolts on the damper don't look like they're anything we service. They appear to hold the component pieces together.

When does one remove / replace those bolts?

Mike

They're supposed to be torqued to a certain spec by the installer, I don't remember what that number is off hand(~16 ft lbs rings a bell).

[Massive Lee]

I find that desintegration of the S54 harmonic balancer very strange. The one on the S14 engine has no RPM limit and is not know to fail. Ran mine to 7800rpm for years. Never had a problem. Never knew anyone with a problem.

[TOOLEAN]

I find that desintegration of the S54 harmonic balancer very strange. The one on the S14 engine has no RPM limit and is not know to fail. Ran mine to 7800rpm for years. Never had a problem. Never knew anyone with a problem.

Maybe the requirements for the long 6 cylinder crank is different from the 4 cylinder crank? Just my first thought.

[Massive Lee]

Maybe the requirements for the long 6 cylinder crank is different from the 4 cylinder crank? Just my first thought.

Indeed, but aren't 4 bangers more suceptible to vibrations?

[wazzu70]

Indeed, but aren't 4 bangers more suceptible to vibrations?

4 cyl and 6 cyl will definitely exhibit different properties. The 6 is more smooth at the bottom of the rev range, but the torsion in the crank due to length gets pretty violent in the upper RPMs. This is where the damper is targeted for use and also why 6 cyl dampers fail on high revving cars.

The 4 cyl vibrates more in the lower rpm range, but due to the short crank and even fire it is more happy in the upper revs. This is why engines like the S42 have no damper at all! Also why cars that spend their life in the upper rpms eliminate the balance shafts if they come with the engine.

Someone mentioned the mass of the flywheel which is a critical part of the equation. Reducing the mass of the flywheel helps a lot since that is less mass twisting the crank.

The damper company BHJ Dynamics has some more in depth than average tech information on their site FWIW. I have done the different harmonic order calculations on various BMW engines. Ill post it up in a different thread when I have time.

[Massive Lee]

Yup. A short crankshaft will not twist at high RPM and will be more stable. That's the reason why Paul Rosche designed the S14 motor as a 4 banger while he already had those 6 cylinder M88/S38 motors that were raced in those 635. Those DTM S14 motors, even in 2.5l trim, were able to reach 9,300 rpm...

[wazzu70]

Here is some of the relevant information for the M5x series motors. I have a group of motorsport engines as well, but I had these screen captures handy so I thought I would post them. I will try and add more soon.

A general overview:


Acceleration orders. The killer is the second order (dashed line). You want the amplitude to be minimised:


Acceleration. This is a cause of the nasty second order torsion "harmonic". You will see some accelerations that are flat or nearly flat on top which is desirable. Long stroke, short rod combos tend to have the dip in the top of the curve which means the piston is accelerating, decelerating, then accelerating and decelerating in a short period of time. This "shocks" the crankshaft and induces funky vibrations (scientific term)


Piston velocity. Nothing too exciting here, but I thought it was worth posting.


Mean piston velocity. This is useful to try and determine a rev limit that is reasonable. Its not gnats nuts, but just a guide to get in the ballpark of what is reasonable.

[TOOLEAN]

Great work Nick, I am still digesting this all...