Who's in for hardend camshafts?
This latest batch were done a little differently . We dipped them in the brine bath with the bearing journals out of the liquid to perhaps keep the temps down a little more and not get them to hard. I also didnt know the metalurgical composition of the 03 cams so they were treated the same as the older cams. If this process can make the butter soft CWR cams survive i think it should make the 03 last more than a few hours. They shipped out today so I should ge tthem by the end of the week.
Nitriding is a low temperature process which is generally under 1000 degrees . But even so can alter the subsurface heat treatment which is range anywhere from none (many dale cams)to well over .030" and all the way through. To go ahead a actually crank the cams up to near the molten temp to reheat treat will for sure warp the cams and require remachining. Mind as well make new ones if that the case. This process has titanium nitride in a molten salt soution which when the cams are exposed for a predetermined time according to their composition will migrate into just the outer surface under .001 " thick. This gives the surface a hardness of 62 rockwell and very wear resistant. The problem that might be occuring with some journals that Tim says has happened is the the subsurface is not hard enough to give the super hard surface a backing and can result in flaking of the metal when run on a hard roller. Although i have not seen this occur on any of my engines (but i do have a bunch of stock ones that did)I took the simple added step of ditching the needle bearings in favor of the pressure fed bronze bushing which have worked superbly for years.
After the cams come out of the bath they have to be cooled according to thier composition as well. So if they are rewelded I have to tell them what the filler material was or stock which was I believe some were en40b.
What some dont understand is that it is absolutly impossible to test nitrided cams for surface hardness with a diamond penatrator. It will crash right through the hard surface and tell you what the subsurface metal is still at. not only that it also ruins the cam as there will now be a super hard cutting edge where it was tested ready to chew right threw a bucket.
After the cams come out of the bath they have to be cooled according to thier composition as well. So if they are rewelded I have to tell them what the filler material was or stock which was I believe some were en40b.
What some dont understand is that it is absolutly impossible to test nitrided cams for surface hardness with a diamond penatrator. It will crash right through the hard surface and tell you what the subsurface metal is still at. not only that it also ruins the cam as there will now be a super hard cutting edge where it was tested ready to chew right threw a bucket.
This is just the pile I have at the shop. Dont know how many more I have on the hoarding shelves.You cant see it on the black cams but on the silver fx400 ones you can see the gold color of the nitride . After they are cooled down the bare metal surfaces get a black oxide coating which I didnt do before but now I polished it along with the journals . The coating is an option for corrosion resistance that they do for free. Most of it has stayed on the cams we did years ago and has just worn off the tips of some so it must be worth it for added wear protection.
The cam in the center had a ball bearing fail so the roller took the load untill it trashed the journal surface. The lobes were perfect so this cam will also be repaired with a sleeve and oil fed bearing.
The cam in the center had a ball bearing fail so the roller took the load untill it trashed the journal surface. The lobes were perfect so this cam will also be repaired with a sleeve and oil fed bearing.