Probability of valve crash after hub spin

[masayoshi]

Hello everyone.
There have been countless discussions about the S55 crank. I've seen all the comments from people who have slipped and have been able to revive it by getting a new hub and adjusting the timing.
What are the chances of actually slipping and valve crashing?
At least I've seen plenty of comments about people slipping, but I've never seen any comments about people valve crashing.
I thought that if almost no one has a valve crash, they should just upgrade to a new hub after slipping.

[VCO]

Originally Posted by masayoshi

Hello everyone.
There have been countless discussions about the S55 crank. I've seen all the comments from people who have slipped and have been able to revive it by getting a new hub and adjusting the timing.
What are the chances of actually slipping and valve crashing?
At least I've seen plenty of comments about people slipping, but I've never seen any comments about people valve crashing.
I thought that if almost no one has a valve crash, they should just upgrade to a new hub after slipping.

A quick search, these two have valve damage.

https://www.youtube.com/watch?v=uA6rGjzNKBU

[masayoshi]

Thank you.
I am curious as to what percentage of the cars that actually slip actually crash the valves.
I found data on a German forum that showed a 0.1% chance of a hub slipping.
(Although on this forum it is much different at 1%).
If 1% of cars that slip do valve crash, then there are really only a few cars that would be a serious problem if they did slip.

[NickyC]

All of those statistics are made up, nobody knows. The problem is overblown. If you're so worried about it, just get another car. I've owned these cars for like 8 years now and no issues ever.

[Yuille36]

I wouldn't say that a spun crank hub doesn't exist, there are some that have indeed encountered this issue. Just because you've never encountered it, doesn't mean it can be ruled out.

I own a E63 AMG with the M156 engine, and our biggest concern was a broken head bolt, that could lead to a blown head gasket. This was buffed for years on the MBWorld forum, and I was concerned so I had my head bolts relaced out of abundance of caution. Once the head bolts were removed and carefully inspected by me and my mechanic, we deemed them not to be defective. It cost me $2300, but I have the confidence to know that these new head bolts will not fail.

Now getting back to the crank hub, is it blown out of proportion maybe, does this issue exist yes, but the number is small as compared to the number of S55 out there. Should you be concerned yes, because it could happen to you. But in most cases, it is caused by owner increasing their horsepower and torque numbers thru modification. And more prevalent with DCT transmissions, down shifting from high RPMs. But it can happen to anyone, if the conditions are right. Although this isn't a cheap fix, a lot of owners have had their crank hubs changed, for peace of mind.

I've owned various Bimmers for years, and my F80 for a year now, I'm not very concerned about it, No. I also do not drive it like a stole it, but probably at some point in the future, I will most likely have it changed, especially if you keep your cars as long as I do. And I'm sure that other owners would agree with my statements.

[summernightruns]

Honestly I have seen bone stock s55s spin their hub. While more torque sounds like it would make it easier to spin, it's hard to be definitive because almost all of these cars are our have been modded.
If you want peace of mind, get it done. It's a hell of a lot cheaper than a repair.

[NSX2M4]

You have a better chance driving over a stick and puncturing your oil cooler which in turn causes engine failure if not monitored.

[RElias21]

Originally Posted by summernightruns

Honestly I have seen bone stock s55s spin their hub. While more torque sounds like it would make it easier to spin, it's hard to be definitive because almost all of these cars are our have been modded.
If you want peace of mind, get it done. It's a hell of a lot cheaper than a repair.

I have no dog in this fight, but I believe you are making an assumption which relates exactly to OP’s question.

My understanding is that without valve crash, the preventative maintenance new hub is the same cost as a post slip new hub.

Is my understanding incorrect?

If my understanding is correct, then the “hell of a lot cheaper to repair” is assuming valve crash has happened.

[N1rve]

Originally Posted by RElias21

I have no dog in this fight, but I believe you are making an assumption which rates exactly to OP’s question.

My understanding is that without valve crash, the preventative maintenance new hub is the same cost as a post slip new hub.

Isn’t my understanding incorrect?

If my understanding is correct, then the “hell of a lot cheaper to repair” is assuming valve crash has happened.

You are correct. You either pay for a crankhub up front or later. Only if you have a catastrophic failure (which is rare) is when it gets expensive. But then you can have a fully built motor. Lol.

[masayoshi]

Originally Posted by RElias21

I have no dog in this fight, but I believe you are making an assumption which rates exactly to OP’s question.

My understanding is that without valve crash, the preventative maintenance new hub is the same cost as a post slip new hub.

Isn’t my understanding incorrect?

If my understanding is correct, then the “hell of a lot cheaper to repair” is assuming valve crash has happened.

I feel exactly the same way and would like to know what percentage of vehicles that actually have hub spin actually have valve crash.

[summernightruns]

Originally Posted by RElias21

I have no dog in this fight, but I believe you are making an assumption which relates exactly to OP’s question.

My understanding is that without valve crash, the preventative maintenance new hub is the same cost as a post slip new hub.

Is my understanding incorrect?

If my understanding is correct, then the “hell of a lot cheaper to repair” is assuming valve crash has happened.

Yes. It's your choice on how you gamble this. I did my own. I was stage 2 ots bm3 on a car that had been tracked and getting up in mileage (70k). But when I went single turbo and ethanol, I decided it was time.

[N1rve]

Originally Posted by masayoshi

I feel exactly the same way and would like to know what percentage of vehicles that actually have hub spin actually have valve crash.

I've only ever heard of 2 instances on the forums personally. Maybe there was more but it's quite rare to hear about.