Vargas crank hub bolt capture question

[Chris@VargasTurboTech]

A customer ordered at a shop by me in Germany he doesn’t want it now but the bolts have gone walkies . I’m fittion on mine but no screws.

M8x1.25x30 12.9 grade

 

[MoreBoost]

My question is why does it fully encapsulate the bolt when it doesn't go under any kinda of stress aside harsh vibration? Wouldn't a metal disc work just as well, and also give you access to the bolt for use while walnut blasting?

It's to prevent the bolt backing out and losing pressure on the sprocket

 

[Erichale77]

It's a good piece of mind. Here's mine Tony made for me for the ATi dampner.

 

[MoistNapkin]

It's to prevent the bolt backing out and losing pressure on the sprocket

I understand it's purpose, older BMW's use a nut instead that owners often locked with wire to prevent backing out.

It's a good piece of mind. Here's mine Tony made for me for the ATi dampner.

That's more like it, I feel that design is actually superior. The user can use the crank bolt for maintenance without worrying about loosening that oh so essential bolt.

 

[fmorelli]

It's a good piece of mind. Here's mine Tony made for me for the ATi dampner.

Curious if the intersection of those smaller circles to the larger may be stress risers.

Filippo

 

[Jeffman]

Curious if the intersection of those smaller circles to the larger may be stress risers.

View attachment 29204

Filippo

Interesting observation. Looks to me that could be a weak point in the design.

I’m also wondering if the functionality of the Vargas crank hub bolt capture can be combined somehow into one piece with the functionality of Ozwerk’s $150 crank seal plate to prevent broken serpentine belts getting sucked into the crankcase...that would be super useful. If not, could both be installed together?
@Chris@VargasTurboTech ?

 

[MoreBoost]

I understand it's purpose, older BMW's use a nut instead that owners often locked with wire to prevent backing out.



That's more like it, I feel that design is actually superior. The user can use the crank bolt for maintenance without worrying about loosening that oh so essential bolt.

Well obviously the greater contact area you can have between the bolt and the capture, the better you can distribute any forces of the bolt trying to rotate and hopefully the less chance of that happening. At the expense of preventing maintenance where you may want to be rotating the crank by hand but you can bump it with the starter.

 

[Erichale77]

The crank seal plate doesn't rotate and the crank capture does. And my capture, although noted it could've had more meat left on it, holds up fine at 850whp. Mine is made of steel rather than aluminum though.

 

[Chris@VargasTurboTech]

As Eric pointed out, hub spins... hard to combine the two.

 

[Jeffman]

Thanks to you both. Now I understand the difference between the two.

 

[The Convert]

Curious if the intersection of those smaller circles to the larger may be stress risers.

View attachment 29204

Filippo

They absolutely are. The smaller a radius, the higher the stress concentration. Now whether or not the stress level this part may see exceeds its capability is a whole other story.

 

[Chris@VargasTurboTech]

Yep, academically they would be stress risers. Realistically? Non issue as the job is to not allow vibes to back off bolt. Low strength requirement, and steel is real. Not to mention it's not a publicly available part (the one for the damper)

 

[MoistNapkin]

Well obviously the greater contact area you can have between the bolt and the capture, the better you can distribute any forces of the bolt trying to rotate and hopefully the less chance of that happening. At the expense of preventing maintenance where you may want to be rotating the crank by hand but you can bump it with the starter.

As mentioned no stress/force is being put on that bolt. The plate is there simply to stop any rotation IF it were to come loose. Which is why you can use just a metal wire on the Crank Nuts of older bmw's. In this case it just appears over engineered which is absolutely not an issue. Chris one post above also describes its purpose as well. I prefer the hand method cranking 10/10, but that's just personal preference on how we work on cars ehh? Cheers!