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New camshafts (again)

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I have just seen the "Hepolite" (wassell) camshafts. Apparently billet? 

I was wondering if anyone has tried one yet?

Paul

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No - but mystified by the term 'billet' being used as a point in favour.

I'd expect camshafts to be forged steel (best for grain structure), or chilled cast iron (best for mass production) or simply carved out of a lump of steel randomly cut from a large plate or bar.  i.e., 'billet'.  Which is inevitable for small manufacturing batches where forging and casting facility costs cannot be shared over thousands of items.

I'm not suggesting anything wrong, assuming they use the right materials, heat treatment, surface hardening etc.  Maybe someone in the trade might know more?

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Curious also on the cam issue for a few decades now.

The documented cam material is EN32B as listed in the various commando shop tech data.

EN32B is a low carbon alloy and the only way to get surface hardness is to infuse more carbon with a residual tough core.

My research of the steel and steel treatment industry that low carbon steels do not respond to nitriding.

EN40 may well be a higher carbon content steel but I have not seen any documentation that norton used EN40 in any of their cams. I had one norton club tech guy say the final commando MKIII 06-2608 (74 partial-75 cam) was a "different" alloy from  06-1084. Strictly word of mouth and nothing to back it up. The MKIII shop manual quotes EN32B.

Certainly, I have heard of the older PW3 as chilled iron... then later AN is using chilled iron. One chilled iron cam, I purchased a long time ago, and it was discovered to split right down the mould part line. It seemed to me a poor crystal structure. I won't use them any more, though some people have some success with them.

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Didn't use it though, had it sectioned, chemistry tested, polished and case depth and hardness measured. Feel free to do the same as it is not expensive to do. 

Chill cast iron is now the preserve of the very large mass market, the quantities needed to make chill cast viable are now huge - far larger than that required in 1999, even beyond some car manufacturers. 

Chilled iron is a generic term for the process, not so much the cast iron used. Early PW3 cams are made from different iron than the latest PW3. It also variable in result depending on the molten metal temp, number being poured and speed of pouring. 

Chill cast was also a cheap and easy way to make a cam, but now there are materials and surface treatments out there that can overcome the reasons for using chill cast. A billet cam would not be an issue for a Norton cam, I have photo proof of this with a billet cam bent at 45 degrees when an engine went bang, sadly it took out the owners RH crankcase though.  

If anyone has a Wassel cam with some miles on it and they think it has failed, please send it to me at AN, it has to be a nitrided Wassel cam though to compare with what I already know. I would also be interested to know how many happy miles you have on a wassel cam. 

 


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