Technical Crank hub upgrade options

[SlowE93]

I just don't understand why BMW has not fixed the issue, they have to make money somehow I guess or an easy way
to deny warranty on a tuned engine when they spin the hub as stock ones have not really done it but the few isolated ones.

Agreed.
100% bullshit factory design

 

[RuskiRacer]

Well I geuss if anyone is gonna break the pins it'll probably be me so we'll see here

 

[martymil]

Well I geuss if anyone is gonna break the pins it'll probably be me so we'll see here

I don't think you will break it, just use a cbc on the main bolt and you'll be right.

What boggles the mind that the s65 runs a cbc from the factory, wonder why.

 

[RuskiRacer]

I Guess thats kinda odd, same hub style with the torque of the bolt holding it in basically? Not like the s65 makes that much torque just not sure why bmw was so in love with that retarted design for so long

 

[martymil]

I think what spins the crank hub is when the bolt loosen due to the rapid rpm changes between gears shifts
especially with dct as it doesn't happen on manuals.

 

[RuskiRacer]

I mean it can happen on manuals it happened to me with a brand new bolt torqued to the insane bmw spec. My mistake was reusing the oem hub with its old friction disks.

 

[RuskiRacer]

I actually feel as if manual cars making good power are the most susceptible to backing the bolt out due to loading and unloading the drivetrain nearly every shift

 

[martymil]

Oh no, you didn't

bugger, live and learn

 

[RuskiRacer]

Oh yes I did lol , couldn't have said it better myself live and learn. Atleast it was on own car and not a clients

 

[martymil]

We all make mistakes sometimes but as long as we lean from them.

 

[NoGuru]

Would installing a Crank bolt capture replace a Crank seal guard?

 

[RuskiRacer]

I think they can work in conjunction with each other

 

[pysical]

Crank bolt capture just helps to prevent the bolt from backing out and causing the crank hub to spin. The crank seal guard prevents the belt from getting sucked into the front seal.

 

[NoGuru]

I get what each one does I am just not sure if someone would run both at the same time of just the crank bolt capture.
To me it seems like that might cover it enough but IDK.

 

[RuskiRacer]

I personally never saw a need to run a crank seal guard, just get a fresh tensioner a good dry belt and you won't have issues

 

[pysical]

I get what each one does I am just not sure if someone would run both at the same time of just the crank bolt capture.
To me it seems like that might cover it enough but IDK.

They both do completely different things. One doesn't help the other. You can run both or either. Doesn't matter.

 

[NoGuru]

Got it, thanks for the replies!

 

[Reformatt]

Personally I wouldn’t go the route of drilling or modifying the crank. Using the VTT Crank Bolt capture thingy would seem to be best option…

Not to bash anyone’s designs but seeing those pins being drilled an inserted into a crank reminds me of the valves we design in the oil an gas industry, they have shear pins in place…don’t care what material is them little things gonna shear off. Just like in our valves better to have a pin fail than trash a hella expensive valve.

 

[martymil]

Personally I wouldn’t go the route of drilling or modifying the crank. Using the VTT Crank Bolt capture thingy would seem to be best option…

Not to bash anyone’s designs but seeing those pins being drilled an inserted into a crank reminds me of the valves we design in the oil an gas industry, they have shear pins in place…don’t care what material is them little things gonna shear off. Just like in our valves better to have a pin fail than trash a hella expensive valve.

Exactly same as on diesels on water and hydraulic pumps, it does matter if it breaks as it can't cause any damage .

Unlike this design if it shears off your in real trouble.

 

[Racetune]

Exactly same as on diesels on water and hydraulic pumps, it does matter if it breaks as it can't cause any damage .

Unlike this design if it shears off your in real trouble.

I'm currently in the market for a crank hub solution. As a mechanical engineer I've been looking at all the different designs trying to choose which one to install.

Gintani design - I don't don't think it's great - the single toothed keyway is going to cause plenty of stress concentrations and it could crack the crank given how thin the snout is in that area.

4 Pin / 2 Pin design - I like this design a lot lot with the issue of - drilling and installation error and loose clearances. The pins need to be a somewhat interference fit at 105c and drilled straight. The pins are in shear - if one or two pins break - the rest will follow and the hub will spin.

VTT V2 - At first I was leaning against this style - but I think the concept makes sense and here's why.
1 - The spine teeth are now straight and not curved - meaning that it will have more positive engagement and embossing of the crank snout.
2 - The factory friction washers are still in play afaik - You still have the factory washers preventing the spline to slip and the crank hub capture to prevent the bolt backing out.

I'm considering the VTT V2 complete solution as the best of the bunch.

Have there been any VTT V2 Spline Lock failures that have used the V2 and complete solution?

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Bmw really fscked this design - it's shit house and tbh it's not a fuse if it causes total engine damage - it's ze Germans cutting costs trying new ideas. Nothing wrong with a woodruff keyway, probably cheaper in the long run considering world wide warranty and you can index and time the crank to TDC very easily. They could have still had the stacked hub with a revised timing case design to allow the timing case to be removed completely for an timing chain service.

Anyhow, have a Winfield