Which grade of aluminium to use
Turbo Mini Forums

Hi Guys,

I am in the process of making a hub to mount my trigger wheel to the crankshaft damper/pulley like the KAD and SC ones.

Is 2014A T6 aluminium alloy the way to go?

If fastcarl reads this what grade alloy did you use for the alternator and water pump pulleys on your beast?

cheers

Mark

H30, or if you want the bullshit name 6082 t4,

2014T6 is a high spec alloy, you will pay a bit more for it and don't need it , use H30, and have a couple of pints with the difference,

carl

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

cheers carl, i'll have a look for some of that

I'd always go for steel on this part to ensure the bolt doesn't lose torque (putting the boss on the damper makes the joint inherantly weaker as you are putting more friction faces in the mix and the bolt has to maintain torque over all of these) - my opinion only, but a loose crank damper can do similar damage to the crank as a loose flywheel.

you are putting all that torque onto a very small surface area (under head of bolt) - do the stress calcs to see if the material will yield under the "static" load generated by torquing the bolt up

just my two penoths worth!

JK

If Carling made Mini engines
it would probably be like this one!

What!!!, i can assure you John' a loose damper will do little more then shag up the woodruff keyway, [experience] the cranks steel the dampers cast iron,
the fella's talking about an adapter of sorts to join one to the other, not having dig[although it may seam] just being practical,

carl

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

Arent flywheels cast iron? well the factory ones anyways.

using your analogy the flywheels wouldnt fret either, but they do.

However I do agree Carl, the only thing that is damaged is the woodruf key and the damper key way. You still dont want it coming loose.

Guess how I know that I think the same way you found out Carl

I agree with John that steel is the material of choice, and not because I have one of Johns excellent peices of workmanship

Edited by Sprocket on 23rd Feb, 2007.

i found the kad one needed spacing off the pulley, the offset wasnt enough....

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

Not with the SC one, nice fit in both standard and MPi pullies

2014 is a good alloy but in the t6 condition is seriously hard!!! We had some sheet in at work and it cracked before we could get a decent fold out of it! A he15 alloy or a he30 alloy would ge more than up to the job. We use lots of these specs on almost all the alloy stuff on the historic f1 cars at work. For high stress stuff we use the he30, i.e suspension bits. p.s. sorry for bad typing/spelling had a lot to drink and have laptop perhed on the bed trying to type this!

I am using a minispares longer socket headed bolt which comes with a 4.5mm spacer which I am pretty sure is steel (correct me if i'm wrong) and this is determining the dimensions of the hub. Here is a preliminary cad mock up.

I think I will try do stress analysis on it and get it so that it is balanced.

Any other inputs and suggestions are welcome

Cheers

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Sorry double post

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Edited by kitch on 24th Feb, 2007.

Hi Kitch - you are right the spacer on the m/spares cap head is steel - I may have a look at the calcs as well out of interest.

Hi Carl - its all discussion, no harm - the way I see it is I don't want anything coming loose which is attached to the crank if I can help it by using the right materials - it may cost a few grammes but save a whole load of grief in maintenece - maybe why my car is still 510kgs.lol!

JK

If Carling made Mini engines
it would probably be like this one!

I did the analysis of the hub to mount my trigger wheel.

2014 Aluminium

Factor of Safety 1.8



Stress distribution



and displacement plot



I'm not sure whether this would be ok or not, this is assuming the whole axial force generated by the bolt is transfered to the hub. In reality it will be less as some deformation will take place in the spacer supplied with the extended bolt.

I looked at using EN24T steel and performed the stress analysis for this and the factor of safety was 6.7 so its easily up to the job. The steel hub weighs 130g and the aluminium one only 48g so it is quite a big difference.








Anyone know where I can buy EN24T bar online or alternatively EN8 as I haven't ,managed to find anywhere yet?

i don't and if i did i wouldn't tell you , lol .

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

I don't get it, why? My uni lecturer said EN24T was the bar I should use and said I could get it from metalsupermarket in cov but I don't have wheels and thats miles from leamington spa.

look in the yellow pages and find your local metal stockholders, most places will have one local. Spoilt for choice round my way, one in our town and loads in a ten mile radius!