Can anyone see a problem....

[gl_s_r]

If I remake these bolts that hold the covers on in aluminium?

[lloydie]

I would of thought they'd be fine as they are only cover bolts and not under any harsh conditions but if they seize your screwed

[VTRDark]

Yeh one big problem. There wont be enough made to go around

No problem that I can see mate. As Lloyd says they are only there....well you know why they are there What about temperature, how would that affect ally, expansion and contraction. Why not use Ti, but then I guess that may have it's own issues.

(:-})

[AMCQ46]

Main problem will be people over tightening them. if they manage to break steel ones, then ally will be carnage............ would be worth putting a smaller bolt head on.... 8mm or an allen key.......to reduce the torque

and will need copaslip to make sure they don't seize like Lloydie said

[lloydie]

Ali slip would be better :-)

[gl_s_r]

I was getting them anodised so they will not oxidise.. plus a little slippage lube when assembled so thought I'd be okay.

They should never be that tight where they shear anyway should they... I may put a hex in them then for an allen key?

Thanks for the input chaps.

[agentpineapple]

I was getting them anodised so they will not oxidise.. plus a little slippage lube when assembled so thought I'd be okay.

They should never be that tight where they shear anyway should they... I may put a hex in them then for an allen key?

Thanks for the input chaps.

don't forget to make extra's.................

[AMCQ46]

the ones I see broken have all failed at the top of the thread where the first shoulder is. That is the part that is under tension when bolted up and must have a bit of a stress raiser where the last thread blends into the shoulder.


I will put the order in for the Ti ones

[VTRDark]

the ones I see broken have all failed at the top of the thread where the first shoulder is.

Same here, and always seems to leave just enough thread sticking out the cylinder to pic the thread out.

(:-})

[mik_str]

I was getting them anodised so they will not oxidise.. plus a little slippage lube when assembled so thought I'd be okay.

They should never be that tight where they shear anyway should they... I may put a hex in them then for an allen key?

Thanks for the input chaps.

don't forget to make extra's.................

here, here

[Bananaman]

im up for a blue anodised set!!!

[gl_s_r]

the ones I see broken have all failed at the top of the thread where the first shoulder is. That is the part that is under tension when bolted up and must have a bit of a stress raiser where the last thread blends into the shoulder.

The first shoulder butts up against the head and as it is a fixed length to the large shoulder at the top, I assume people must be thinking you can tighten them up more and they clamp down the cover and compress the seals more when in fact they don't and all you are doing is stretching the thread. As such all you will do is snap the bolt as it has no where to go depth wise.

I could put a radius in that position to help but there is only a slight counterbore to the top of the thread on the heads so can't put a sensible radius in that corner or it'll bind up.

The only sensible thing I can see to help is to make sure you just don't over tighten them, as trying makes no difference whatsoever to the clamping force of the bolt head against any of the seals to do with the cover.

For interest the shoulder length is around 41mm... the cover is around 35.5mm... and the seals add up to around 6.5mm so the seals get compressed around a mm or so and then that is that... if they leak then they need replacing rather than the bolts need tightening.

Hope that helps with the idea that I can make them from aluminium with no ill effects and the fact I shouldn't need to tightening them up to 300Nm to work...

I would do them from Ti but it's heavier

[Jamoi]

Just out of interest, what's your thinking behind making Ally versions? Purely weight saving?

I've got an idea, might be daft but see what you think...

[AMCQ46]

Mark,
you are correct on how the design works, and its ham fisted assembly that causes failures........... I just get to see them when they need fixed

putting a small allen key head in would help reduce the psychological torque setting

[gl_s_r]

I can see your solution there young Jamie and not a bad one but your right, it's just for weight saving as I'm looking at little bits as I build that can be changed.

So no point in going your way personally for me as it will be swapping steel for steel.