N54 crank hub issue - power level?

GreyNBlueE92

Sergeant
Oct 3, 2018
266
92
0
27
OH
Ride
2007 E92 335i
Press it in with one bolt and finish the job with a new bolt. But i completely agree with it being kind of like vice grips...
 

Terry@BMS

Sergeant
Platinum Vendor
Jan 23, 2017
462
379
50
Good point on the S55 vs. N54 crank hub issues. It'll be interesting to see how the spline setup works out across platforms- especially those that are more prone to the issues to begin with such as with some S55's.

As for the N54 crank hub issues it seems that some have claimed to have tremendous issues with it, although as you state it seems to not have a reputation for it. Have you ever spun an N54 crank hub yourself or seen it happen up close and personal? Everything we hear about on the N54 engine failure front is simply popped pistons it seems.

No generally just pistons is all I hear about. May happen but it's not often reported at least to me.
 
  • Like
Reactions: Rob@RBTurbo

fmorelli

Lieutenant General
Staff member
Aug 11, 2017
3,748
3,592
0
57
Virginia
Ride
E89 Z4 35i, F10 535d
With the spline lock it seems that it is going to only aid, rather than "lock", by providing more of a internal vice grip like lock on the crank inner hub. Vice grips definitely help as we all know, but we also know they can slip with relative ease too.
Poor analogy if one stops and think about it, especially given the preamble of credible discernment. Vise grips don't operate on the same principle as the spline hub. First, vise grips are not captured like a spline hub. Second, vise grips have an articulated locking arm that can release. Third, under significant load even the stoutest vise grips can bend - Stahlwille just replaced a set for me. Fourth, and fifth, and several more I can go on but I think the difference is well established. It's like comparing a screwdriver to a garden shovel because they are both pointy.

The other thing - it's like comparing someone's turbo product to a house window fan. Nice analogy in that it conjures up something cheap and not particularly powerful.

Filippo
 

Rob@RBTurbo

Lieutenant
Dec 7, 2016
626
401
0
St. Louis, MO USA
www.rbturbo.com
Ride
'08 335i, '14 M6, '15 Tundra
Poor analogy if one stops and think about it, especially given the preamble of credible discernment. Vise grips don't operate on the same principle as the spline hub. First, vise grips are not captured like a spline hub. Second, vise grips have an articulated locking arm that can release. Third, under significant load even the stoutest vise grips can bend - Stahlwille just replaced a set for me. Fourth, and fifth, and several more I can go on but I think the difference is well established. It's like comparing a screwdriver to a garden shovel because they are both pointy.

The other thing - it's like comparing someone's turbo product to a house window fan. Nice analogy in that it conjures up something cheap and not particularly powerful.

Filippo

The analogy is spot on IMO. Both use a one-time pressing force of one object to another in attempt to seize the one against another adjoining piece of hardware by means of etching. There is nothing machined, nothing locking, nothing sure. Just a pressing force, some amount of a positive etch, and let's hope it doesn't ever break loose under load.

But it is great that some are willing to take the "positive lock" and "dig deeper" bait, without them no one would give it a whirl to report something sure back in years to come.

Rob
 
  • Dumb
Reactions: gorspeed and veer90

fmorelli

Lieutenant General
Staff member
Aug 11, 2017
3,748
3,592
0
57
Virginia
Ride
E89 Z4 35i, F10 535d
The analogy is spot on IMO. Both use a one-use pressing force of one object to another in attempt to seize the one against another adjoining piece of hardware. There is nothing machined, nothing locking, nothing sure. Just a pressing force, some amount of a positive etch, and let's hope it doesn't ever break loose under load.

But it is great that some are willing to take the "positive lock" and "dig deeper" bait, without them no one would give it a whirl to report something sure back in years to come.

Rob
Rob the issue is not where they may be the same, but where they are different, as I pointed out. You can point out all the similarities you want - it's the DIFFERENCES that make it not the same .........

Like one of your turbos and a house fan. Lots of similarities I can point to, but not a sensible comparison given fundamental differences.

Filippo
 

Rob@RBTurbo

Lieutenant
Dec 7, 2016
626
401
0
St. Louis, MO USA
www.rbturbo.com
Ride
'08 335i, '14 M6, '15 Tundra
Rob the issue is not where they may be the same, but where they are different, as I pointed out. You can point out all the similarities you want - it's the DIFFERENCES that make it not the same .........

Like one of your turbos and a house fan. Lots of similarities I can point to, but not a sensible comparison given fundamental differences.

Filippo

No one said it is literally a vice grip. Just said it works with the same premise in mind by generating an etch by a pressing force to attempt to hold items together. If you believe in it and think it is a superior offering, then pick one up it is all good. Personally I'd hang back for the Spline Lock 2.0 in 2019-2020.

Rob
 

iminhell1

Sergeant
Jun 17, 2018
419
207
0
I've money shifted my auto, and lived to tell about it.


Had about a week where my trans wasn't happy. Started at the drag strip. Locked my in 3rd after hard launches. Never looked into it, just clear and keep racing ... problem persisted.
Changed fluid/filter next weekend.
Went out for street fun. Progressively got deeper and deeper with the car. Then the trans acted up again, locked in 3rd. Clear code and ran another race, 5th slipped bad.
Called it a night.
On my way home I was slowly loading 5th and watching live data. Deep into triples 5th slipped (disappeared) and it downshifted to 2nd!
No idea what RPM was. It was well past redline, and then some. Grabbed neutral and coasted to the shoulder. Car still running I looked it over. No visible leaks/holes. Called it a win and it's been fine since.
Still have no clue what was going on with it. Been just fine since, couple months now.
 
  • Informative
Reactions: veer90

iminhell1

Sergeant
Jun 17, 2018
419
207
0
No one said it is literally a vice grip. Just said it works with the same premise in mind by generating an etch by a pressing force to attempt to hold items together. If you believe in it and think it is a superior offering, then pick one up it is all good. Personally I'd hang back for the Spline Lock 2.0 in 2019-2020.

Rob



A pipe wrench analogy may be more correct. Since the harder you press the deeper it grabs.
 

Rob@RBTurbo

Lieutenant
Dec 7, 2016
626
401
0
St. Louis, MO USA
www.rbturbo.com
Ride
'08 335i, '14 M6, '15 Tundra
A pipe wrench analogy may be more correct. Since the harder you press the deeper it grabs.

If you buy into the marketing then sure. But if you see that the splines are not going to grow in OD once "etched" into the crank, nor is the hub going to protrude deeper into the crank in a slip event... then you'll see that it is just a one time grab and pray more like a vice grip. Ultimately it will help just not sure how the results will vary over time/abuse, unlike something that is actually positively keyed.
 

fmorelli

Lieutenant General
Staff member
Aug 11, 2017
3,748
3,592
0
57
Virginia
Ride
E89 Z4 35i, F10 535d
I don’t get what has happened here...Tony has acquired fan boys and Rob is the only person making sense. Have I traveled to a world where shit is all backwards?!?!?
I don't play identity politics. I explained why the analogy is not appropriate and my commentary stands on its own. Come to your own conclusions as you wish.

I didn't comment on the rest of Rob's many observations, mostly because I either believe he's right (e.g., only time will tell) or I don't have the experience to weigh in (e.g., keyway better solution).

Filippo
 
Last edited:
  • Like
Reactions: TheFixer
Oct 24, 2016
1,152
1,202
0
45
Scottsdale, AZ
I don’t get what has happened here...Tony has acquired fan boys and Rob is the only person making sense. Have I traveled to a world where shit is all backwards?!?!?

Not sure if I should PM you a number so we can have a discussion and further your understanding, or if I should just PayPal you a few bucks to buy a strong drink and contemplate the mess your life has turned into. :grinning:
 

Terry@BMS

Sergeant
Platinum Vendor
Jan 23, 2017
462
379
50
On the S55 at least keep in mind what is generally spinning isn't always the hub on the crank snout, but the timing gear that is not directly locked to the hub. So the one piece design should eliminate many of the failures outright. The splines (according to their testing) increase the amount of torque it takes to spin the hub on the crank.

I would also be interested to see how the crank snout looks when you remove the hub. But let's face reality here, cranks are relatively cheap, often we replace them when doing builds anyway due to them being out of spec. So even if this was a one time use solution (they claim it isn't) and you can't reuse crank again next rebuild, that's hardly a big issue.
 
  • Informative
Reactions: Torgus

Rob@RBTurbo

Lieutenant
Dec 7, 2016
626
401
0
St. Louis, MO USA
www.rbturbo.com
Ride
'08 335i, '14 M6, '15 Tundra
Not sure if I should PM you a number so we can have a discussion and further your understanding, or if I should just PayPal you a few bucks to buy a strong drink and contemplate the mess your life has turned into. :grinning:

Genuinely curious but why does every conversation need to be taken offline? Not just this one, but literally every one and every time. Are forums now a place where we all just duck out of discussions when challenged? Or are forums still a sound place for these discussions to take place?

Perhaps just show a picture of the etches that are made via the press effect, talk a bit about it without the marketing gimmicks and tech jargon, and thereafter all be merry with those strong drinks on this lovely Friday?

I would also be interested to see how the crank snout looks when you remove the hub.

^ This.

Rob
 

The Convert

Captain
Jun 4, 2017
1,487
1,052
0
Ride
335
Rob why don't you make a crank hub since you seem to know everything about why the VTT one won't work. I'll wait
From how I am reading Rob’s comments, he isn’t saying it won’t work. He’s giving reasons why he thinks it isn’t as solid a design as the keyed hub, and asking for more info and “proof” that it works. He’s not even close to out of line to ask for more data. Hell, Tony says no one collects more data than he does when testing things. So, he should have it to share.

We’re just trying to get simple things before we make up our minds as to which direction we would/will go if we ever need to. If you, or anyone, thinks an informed customer is a bad thing, then that’s a totally different conversation. More data/info=more informed clients=better clients.
 

Rob@RBTurbo

Lieutenant
Dec 7, 2016
626
401
0
St. Louis, MO USA
www.rbturbo.com
Ride
'08 335i, '14 M6, '15 Tundra
From how I am reading Rob’s comments, he isn’t saying it won’t work. He’s giving reasons why he thinks it isn’t as solid a design as the keyed hub, and asking for more info and “proof” that it works. He’s not even close to out of line to ask for more data. Hell, Tony says no one collects more data than he does when testing things. So, he should have it to share.

We’re just trying to get simple things before we make up our minds as to which direction we would/will go if we ever need to. If you, or anyone, thinks an informed customer is a bad thing, then that’s a totally different conversation. More data/info=more informed clients=better clients.

Indeed.

To top it all off it is so simple to illustrate, as the single most compelling piece of data would be simply to show a picture of the trace paths and/or show us know how deep the grooves are cut (or thereabouts)... really that is about it. Don't fib it to appease the cause either, please, we do not want to see a 3rd party have different results later.

The fear is that the "etch" will be very shallow (ie. a few thou at best), or in other words not nearly enough to bet your engine on for those looking for something that is an end all be all positive locked solution. Not that this is an issue, that extra "grip" may still be worth it to many for convenience and the dollars spent. Just call it as it is without the "slip and she'll just dig deeper" BS. At the end of the day it is being compared something that is positive keyed, i.e. "much cheaper and the same functionality", we are just not so sure that is the case.

Rob
 
  • Agree
  • Like
Reactions: Torgus and kayzrx82

kayzrx82

Corporal
Apr 4, 2018
110
88
0
Ride
n54 335i
I see nothing wrong in asking for a picture of the splines after removal of the hub. I asked for this in the beginning or just some hard number data of what torque number the hub held to. A critical part such as the hub redesigned like this with splines is an impressive feat. Just would like some data to validate it .
 

MoreBoost

Sergeant
Jul 27, 2017
356
143
0
Ride
335i
What about some type of slipper clutch in the pulley to prevent excessive load and slip?

It's a timing chain. The valves would end up out of sync if a clutch was used. The sprocket is doing the slipping (like a clutch) and that's the issue right.
The chain can't move the sprocket and the valves quick enough under certain circumstances.