s54 harmonic balancer failure

[jason89i]

grenaded the stock harmonic damper on my s54.

Not exactly sure the moment it happened. But I had a student in the passenger seat, coming through a long full throttle carousel (~7500rpm.) 85deg exterior temp, oil temps around 260deg. I immediately noticed the engine vibration and change in engine sound. I backed down, pulled into the pits. I assumed it was a spun bearing .... it is an s54 after all. I found the serpantine belt (2) teeth over on all of the pulleys. After getting it home, my buddy noticed some strange wear marks on the harmonic balancer..... it was scraping against the tdc eye hole. Pulled the pulley off, here's what we found.......

I have heard rumor about them exploding due to overheating.

Is this common? Should it get a seperate duct for cooling? Any other alternatives?

Now what? Thoughts, comments, recommendations....... snide remarks?

Cheers, Jason

[TOOLEAN]

I know some racers are running a duct pointing straight to the balancer, also Terry from Vorshlag is rumored to be making a damper for the 330, he might have some insight.

Good Luck!

[robjohnson]

The 8k rev limiter is for show. Put a duct on it and keep the revs down.

[Mike S]

In the long run, ATI can make a custom damper for you, but it's a bit inconvenient since (a) they insist on having a stock one from you to build theirs and (b) they take 60-90 days to do it. I can live with (b), but (a) is silly since they've done these before.

The cost is supposedly around $800, and they require a $250 deposit to start the process.

I'll likely place an order for one in the next two weeks. PM me if you want to piggyback on my order.

Mike

[Mad Dog 20/20]

VAC has what looks like a nice S54 damper

[gobuffs]

It has been suggested for years to duct the balancer on the Euros and the S54. It is on my to do list.

I have an extra one as a spare. One day I'll get an ATI one. Are we sure it is better than stock?

[=BA=]

BMW Motorsport P54B32 race engines actually use the stock factory part.

I would just replace it once in a while (maybe send them an email, asking what their replacement interval for that part is?)

[Mike S]

VAC has what looks like a nice S54 damper

I don't see it on their site. Link?

[Mad Dog 20/20]

I don't see it on their site. Link?

They had an S54 on display at MFest-East last month. It had the damper. I thought it a bit odd and asked about it, and the VAC guy said the OE fails w/ race duty. I'd call and inquire.

[jason89i]

pics of ducting solutions?

[gobuffs]

You can use a brake duct style system. I am planning on using a NACA duct from the under tray. Doubt it will need any hose. The duct should just point right at the balancer good enough.

[ninekrpm]

Anyone talk to James @ BW about a solution?

[craz azn]

Common failure on a high rpm straight 6. The Grand Am Cup guys used to replace these every few races as regular maintenance, so that should give you an idea of replacement intervals... assuming you don't drive it as hard as they did.

[BMMMW14]

Ditto - In Grand AM it was 2 races and then in the garbage.

Common failure on a high rpm straight 6. The Grand Am Cup guys used to replace these every few races as regular maintenance, so that should give you an idea of replacement intervals... assuming you don't drive it as hard as they did.

[Def]

The ATI dampers can sometimes make things worse if they "get the math wrong." A bunch of guys destroyed RB26DETTs with the off the shelf ATI damper (I6 2.6L Skyline GTR engine, 8k RPM redline stock). There are some big ATI dampers meant for other applications that keep the engines happy at ~9k RPM. Not saying the S54 ATI damper is garbage, just saying be careful as it can make the situation WORSE.

RB26 guys also have good luck with solid crankshaft pulleys. Keeps vibes down outside the natural frequency where a dynamic vibration absorber gives you a bunch of peaks.

[Fair]

I know some racers are running a duct pointing straight to the balancer, also Terry from Vorshlag is rumored to be making a damper for the 330, he might have some insight.

Good Luck!

Yes, we're waiting on the first prototypes. The style we are making isn't a solid pulley (that was a reliable and more cost effective solution, but not actually a better balancer solution), but a real multi-piece polymer insert damper, which will be both modular (with bolt-on front serpentine pulleys for the differing A/C drive styles) and rebuild-able. We're going for the 2 variations to fit the E46 M54 first, as well as E36 S50/S52 and M50/M52 variations.

I will try to get my hands on an old/used S54 balancer and see if we can make a version for that one. Anyone have one they have "used up" but is still mostly in one piece?

Air ducting for the OEM balancers?? (facepalm). I get it, but that's still kind of sad that you have to resort to that to keep them alive. And the "2 races and its garbage" limit is also another sad joke. Is there anything made with polymers on a BMW that doesn't turn to dust or goo when it gets hot, or ages past 5 years/50K miles??? The list of "common maintenance items" on a BMW is absurdly long compared to almost any other brand. I've owned and raced in many makes and model, and there are some unusual OEM parts failures that only seem to crop up on Bimmers. Not trying to hate, just a frustrating, first-hand observation.

Good luck to the OP. Wish we had a solution for the S54 sooner...

[bawareca]

...........
Air ducting for the OEM balancers?? (facepalm). I get it, but that's still kind of sad that you have to resort to that to keep them alive. And the "2 races and its garbage" limit is also another sad joke. Is there anything made with polymers on a BMW that doesn't turn to dust or goo when it gets hot, or ages past 5 years/50K miles??? The list of "common maintenance items" on a BMW is absurdly long compared to almost any other brand. I've owned and raced in many makes and model, and there are some unusual OEM parts failures that only seem to crop up on Bimmers. Not trying to hate, just a frustrating, first-hand observation.

Good luck to the OP. Wish we had a solution for the S54 sooner...

You are partially correct,but I have to add that it gets worse over the years.BMW,same as Mercedes went from overbuilt to underbuilt.

[Mike S]

Grand Am is serious stuff. They are going to do all the preventive maintenance possible to keep expensive failures from happening. And a single debilitating failure can kill an entire season... so the expense of that mounts rapidly.

ATI is one of the most respected harmonic dampener companies on the planet, but nobody is perfect. There *are* S54 ATI dampeners out there. Has anyone heard of any failures on them?

Now, compare that with the stock S54 dampener. I know which way I'm going. If I were mounting a multi-million dollar race effort, I'd probably still replace those repeatedly during the season.

As for ducting, the dampeners are converting mechanical energy into heat. Ducting makes sense to me in a high heat environment that won't cool the dampener quickly.

Terry, that's a great service you're adding, providing improved dampeners for the engines you mentioned. I've been told the M50/M52/S50/S52 version will be tricky since the crank timing teeth are integrated with the dampener.

Mike

[magnetic1]

Grand Am is serious stuff. They are going to do all the preventive maintenance possible to keep expensive failures from happening. And a single debilitating failure can kill an entire season... so the expense of that mounts rapidly.

Mike

Not to mention most of the drivers pay big bucks to run. At that level, you better be sure the car is in top shape every race. Hell, even our little GTS2 rental at the club race level sees replacement of stupid little parts.

[flink]

It has been suggested for years to duct the balancer on the Euros and the S54. It is on my to do list.

I'd have thought that a more effective way of cooling it would be to increase the surface area: fasten a finned aluminum heatsink to the front. It's spinning nice and fast so the air flow would be good.

Assumes that the a/c pulley is removed. Some attention to the thermal bond between the aluminum and the steel would be needed - electronic heatsink grease, perhaps.

otoh, poly is a poor conductor. It could be that the problem is that the rate of poly->steel heat conduction is too low, so no external cooling scheme will be effective.

[Def]

Air ducting for the OEM balancers?? (facepalm). I get it, but that's still kind of sad that you have to resort to that to keep them alive. And the "2 races and its garbage" limit is also another sad joke. Is there anything made with polymers on a BMW that doesn't turn to dust or goo when it gets hot, or ages past 5 years/50K miles??? The list of "common maintenance items" on a BMW is absurdly long compared to almost any other brand. I've owned and raced in many makes and model, and there are some unusual OEM parts failures that only seem to crop up on Bimmers. Not trying to hate, just a frustrating, first-hand observation.

While I understand ducting the balancer in an application that's throwing a ton of energy into it (it's just like sealing up a shock and being mad when it boils the fluid during a race), BMW's rubber quality is so substandard it's not even funny.


I was absolutely shocked when I started getting into early 90's Nissans at just how long their rubber stuff(usually made by Bridgestone) lasts compared to European stuff of the same vintage. My S13 track car is still running the STOCK guibo with ~165k miles, and the last 20k miles of it mostly on track at over 3 times the stock HP level. It's still in good shape, and you never ever hear of anybody having to replace it due to failure, even on cars with 700+ rwhp. Still on the stock driveshaft center support bearing too!



To Vorshlag,
I'm a bit curious on if you're doing instrumented testing for your dampers to actually find the crankshaft's harmonic peaks, and if those change with a lightweight flywheel (I've gotten some info that says it does indeed change quite a bit with a lightweight flywheel). This might also contribute to harmonic damper failures since you would essentially be out of phase with the actual crankshaft at all frequencies, so you might get a ton of harmonic peaks as you sweep through the rev range just by putting on a lightweight flywheel.

[flink]

I'd have thought that a more effective way of cooling it would be to increase the surface area: fasten a finned aluminum heatsink to the front.

hm, there's a bolt-on aluminum heatsink already available. The a/c pulley. Not as efficient as it might be, but leaving it on there will provide *some* additional dissipation.

[Gofast]

It could be that the problem is that the rate of poly->steel heat conduction is too low, so no external cooling scheme will be effective.

And the poly is under a huge amount of cyclic loading.

A 6" dia disk @ 7k rpm is experiencing ~4300 gs. I don't know offhand how much that balancer weighs, but that's a lot of force.

[raydoc]

I all ears waiting for a good aftermarket unit. I did in one motor with a torn balancer and have now heard of many people whose mystery vibration was a toasted balancer or who's motor then grenaded.

[delirium45]

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