Hi Chris
I said i don't know i'm trying to get the original blue prints from Paul Ivy
Graham

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"It's better to be not informed than ill-informed"

I don't know about epic but this has turned into a pissing competition. Half of these posts should be PM's It really looks poor that some very very knowledgeable people on here start to carry on like children. This thread should have been left locked.

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Your silliness has been noted.

I think it should run.
Let the people that know this stuff work it out.
Others with less knowledge should not interrupt unless they have question
or a bit of humour or something.

Hey scotta_74, fine. If you don't like it, don't read it.

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Pretty please, with a cherry on top. Keep it effing civil?

I'm sure plenty like me are enjoying the discussion and learning heaps, but the pissing contest makes everyone involved look like school kids...

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Simon

The adventures of an owner builder in the Tallarook Ranges

Maybe someone should make a crank out of Nylon or Ebonite, that might work.

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Have a Nice Day.
If already having a nice day please disregard.

it`s cool,,, these guys will sort it out,,,,, won`t you???

it`s healthy discussion, right boys???

& Besides,,, we`re all little kids, no matter who we are,,, & if you diss-agree then you`re lying

so,,, GR , send the sample

GT, test the sample

i`m almost more than half agreeing with GR, but i don`t have enough knowledge about metallurgy to input much

& i`m almost half agreeing with GT too because i,,, after many years of "Feeling" this crap with big donks & big revs, & then seeing results of others doing things differently to Dad,,, well,,, i`m keen to see the facts of at least one particular crank,,, that`d be pretty damn cool

if you`re not keen to see the results,,, or if you want to just see the p!$$ fight through... then cool,,,, lets see this one through & then walk/run/sprint through the valve spring debate immediately after, while we`re on a roll

i love facts,,, they beat all pub talk,,, feeling it & seeing it & then "Knowing" it is better than just imagining it

GR,,, send the crank

GT,,, test the crank

OK???

then lets get on with the valve spring thing

in the mean-time,,, i`ll talk with my Guy in China & we`ll see what their best material that China is using for cranks these days & compare

yeah???

this is a damn good thread,,, Please do not stop this thread,,, it is one of the very most important pieces of the puzzle that this forum has endured so far & needs to be seen through

BUT!!!!!!!!!!!!! Gentlemen,,,, lets stay classy gentlemen,,, no pulling hair or scratching eyeballs ok???

Let the games begin, But be nice & we can all learn from this

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Not quite correct about england being the only country to make EN40b.
Now the EN part was a standard code[EN=EN-glish] and the 40 code is a carbon content base, and the b is a code for the other metal elements.

The EN system standardized in UK in 1959 and continued until 1990 when just about all countries standardized on their own internal codes, but also complied to world wide codes, IE AISI american iron and steel insitute, SAE for automotive production and Werstoff number which is the european DIN then there is japan, china etc,etc.

So if you asked for a lump of EN40b then here in Aust. the code number is BS.970.722M4 [Aust works under the british standard for steel] but has a Aust standard for construction compliance.
Now B.S. 970. 722. M. 4.
BS970 is british standard for the base grade of the metal

722 code for a alloy steel. you then look at the code No. in the british std. and it will give you the composition.

M supplied to a particular mechanical property. IE machineability

4 the mean carbon content x 100.

So this particular grade of steel has equivalent composition listed in all other countries standards.

4140 and 4340 are AISI standards and if you look up the composition for them and cross reference them to a BS number guess what the numbers come up and then cross reference back to the old EN No's and the chemical composition is the same as en40b and en41b.
If a particular composition is not manufactured then there is a cross reference with all world wide steel producers to a steel that is very close.

all this was done because if a ship was built in say europe and you were broken down in singapore and under your class certificate the componet was made from say en40b then you can source a equivalent in asia. World wide standardization.

http://www.mencinger.biz/SteelData/Equi ... 0Steel.htm

The poms still use the EN system for their domestic supply thats why if you look for en40b england is the only country to list it as en40b

Like this stupid metric system we have here. It was supposed to make things simpler but, the imperial system for ever

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Research is the difference between speculation and investment. Anyone who copys some one else will always be second
www.minisprintgt.com

I didn't go into that, because it was not relevant to Matts point. His point was corrosion resistance I just mentioned in passing that in ferrous steels, Cr needs to be present in some quanity along with other alloying elements.



Incorrect



When did the start making 4140 with Al in it. And what is its correct designation. It wouldn't be SAE 4140 anymore if it had Al in it.



Please read




I wasn't denying that you could use tool steels for making crankshafts.
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GT mowog, please keep this in mind...

I was refering to" tool steel" as high speed steel . H13 is classified as a steel for tool making ie dies, punches and injection moulding etc, it is NOT a tool steel like HSS
If is was a compund like HSS then you would have to anneal it to machine it and any slight heat what so ever would re-harden it. If you ever got a crank made out of it it would shatter like glass but never wear out.
Injector pump plungers in big diesels are made from H13[and similar compounds] and then hardened and ground to survive the gritty crap HFO going thru them.

with H13 any surface hardening must be localised IE a punch end and the hardening is only a few thou deep and maintain a non hardened core or it will impact and stress crack. In its unhardened state it is very tough and will withstand a relatively high impact, but it's down side is that it will work harden and become brittle. Might be OK for a drag car when the crank only does a couple of runs.

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Research is the difference between speculation and investment. Anyone who copys some one else will always be second
www.minisprintgt.com

Just to be clear on this, are you saying that you like to make your cranks 'stiff' so they rigid and resist 'flex' etc?

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Great stuff GR...can't help thinking though that if BMC had spent just a few more dollars on crank design and mounting to get rid of whip then the nitriding would have been the icing on the cake

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"Show me the Mini!"

it`s funny tho (i reckon) because there seems to be a need for "Some" compromise,,, now i actually hate that word "Compromise" , i don`t like having to compromise,,, i`d much rather have the best in everything,,, but with regards to cranks & from what i`ve learnt over the years, there is a need to have a stiff crank that resists twisting/flexing, but must also be hard enough to resist wear as well,,, that (to me) Must be a compromise in materials & treatments,,, it`s therfore the balancing of the composition & the processes placed upon the item to allow the best "compromise" for it`s intended purpose

The info in this thread is awsome & i think it`s well overdue

Now, getting onto what Mick just said,,, i reckon BMC did a pretty damn good job at Compromising,,, here we have an ancient design, adapted for the mini purpose from an even more ancient design,,, yet the bottom ends hold up relatively well with 200hp,,, when the original ancient design was barely able to hold 25hp without dramas,,, so the cranks actually do a damn good job & the 3 mains allow less frictional losses (when built well) less than the friction that a 5-main crank endures

but then the stiffness of the 5 main would surely allow even more power with less fatigue yeah?

so it`s all been a compromise process the whole way along the evolution of the mini engines components

later materials & chemical properties & metallurgy & machining processes have seen some awsome strong products being produced,,, but we still have an ancient designed 3 main engine still producing more & more Horse-power & able to cope very well indeed even with age old materials... IE: there are still some original "S" cranks buzzing around copping well over 150hp,,, how good was the original design/materials that we can have this ???

i`m loving this topic

Edit--> great info on the materials etc David,,, clears up lots of stuff for me & very calmly & sensibly put... well done

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

I think that if an extra main bearing is needed it probably should be behind the flywheel.

(just one crank after another)

Matt,

Thanks for your further input on what your dad did all them years ago. Just a little more info, Nitro-carburising is a general Treatment Term and Nitriding, Tufftriding etc are specific types of Nitro-carburising.

If GR sends it, GT will have it tested - independantly and post the test certificate. Mark my words.

GR, why not post the results from the testing you have had done?

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