The last few cams I ordered didn't have this copper color to them. anyone know what this is?

 

You could call and ask them but normally the copper color means it's an 8620 core like from cam motion which is a huger steel grade

 

That is what my 224/228 I ordered a month ago looks like.

 

As I understand, the copper coating is for the heat treating process. It allows the lobes to be hardened for long wear while the shaft remains ductile for easier straightening and resistance to breakage. It is typical for 8620 and a few other alloys that are oven heated as part of the hardening process.

 

Pretty sure that's what my Tick cam looked like, as well as a FTI/Ed curtis cam from several years ago.

 

Never noticed will have to look.

 

IIRC Crane Cams was one of the world's largest suppliers of camshaft cores and I've seen their stuff look like that (gold) for years. American quality.......tried and true.
Comp probably tried saving a buck or two with inferior China metal which is likely a blend of rusty car fenders and Schlitz cans. Clearly the lobe rates and elevated spring pressures were not a good combo and plenty of LS folks have paid the price for corporate bean counters.
That particular camshaft pic passes the eye test.

 

That's what Cam Motion cams look like, or at least did a few years ago.

I remember Comp's cams being black in the unmachined areas.

 

The copper looking cores above are make of 8620 or 9310( 9310 small chance) most likely 8620. Three company's that I know of make these LSM, Andrews, Callie's and us Cam Motion. The copper coating is just a mask for the heat treating process just like speedtigger said. They can cost up to twice what the 5150 can cost.

 

KIP,

Its my understanding that one of the 3 companies making cam blanks uses something like grey iron which is not desirable for roller cams. (Correct me if Im wrong Please)

Of the 3 cores available these are the least expensive blanks and typically what Comp will use depending on what's available to them. Since Comp does not buy blanks in bulk, The usually order 50 blanks at a time from other companies possibly like yourself who will buy in bulk.

I am only interested in the background of the cores that are available to cam grinders such as your self. Not trying to get you to out Comp or other manufactures.

If you could at least please comment on what's available to you as a blank it would be much appreciated.

The cam industry is a very small community and I just want to make sure the info I was given is correct.

 

It is typical for 8620 and a few other alloys that are oven heated as part of the hardening process.

 

Roller Camshaft Materials



There is a fairly broad spectrum of materials and heat treating methods used in the production of roller camshafts. There are more than three suppliers now as many companies continue to outsource internationally making it harder to verify material and heat treating specifications. First, gray cast iron is not used. For most FLAT tappet camshafts, the cores are made from cast iron, but a special cast iron. I am not addressing here the materials for flat tappet cores. The commonly available steel for roller cams are 1050, 1060, 1080, 4150, 5150, 5160, 8650 and 8660. All of these steels are available in different qualities or grades. All of these are high carbon steels and have higher carbon content in the steel for surface hardness created in the heat treating process. 1050 has .5 per cent carbon 1060 has .6 per cent carbon. To manufacture a camshaft blank from these steels the process is much simpler than for the 8620 or 9310 steels. The high carbon steels are “spooled out” meaning they are grooved to space the lobes /bearings / gears to the correct linear position and diameter. After that they are “lobe milled”. That refers to the process that creates the lobe shape and position which determines what lift, duration, lobe separation and cylinder firing order that blank will make as a finished cam. Next is the heat treatment process to produce the case hardness on the lobes. This is done with an electrical induction coil that goes around one lobe at a time. The lobe is heated up to a specific given temperature and time depending on the material ( it will be red hot). Then it is “quenched” or cooled by either spraying down or dunking into a water/polymer quench. That is all there is to the heat treat process. The lobes are now hard.

The 8620 steel has a lower (.2 per cent) carbon which requires the cam core go through a different heat treating process because of the lower carbon content. The lower carbon content produces a stronger part, not a harder part. They first have to be spooled like the other material cores, but after that they must be copper plated. The copper plating is a masking agent for the sections of the cam that you do not want to get hardened. After the plating the copper is removed from the O.D. of the cam, leaving the plating only on the shaft in between the lobes. Next is the lobe milling which is just like the induction a hardened camshaft. After they have been lobe milled they are sent to heat treat. The heat treatment process for 8620 and 9310 is referred to as carburization. The common cycle for 8620 or 9310 is to put in a carburizing oven at 1750 degrees for 36 hours, then it is cooled to 1475 degrees for one hour, then oil quenched, then tempered to 300 degrees for 3 hours, then air cooled. The 9310 material requires a deep freezing process at this point. After that process it is media blasted clean and jet wash cleaned. We then straighten on a 25 ton hydraulic press. After straightening they are ready for the grinding of the bearing surfaces. At this point the core is ready to be ground to a finished camshaft.

Which is the best? I think 8620 is the best. It has been proven over the years.

The 5160 steel from what I know from talking to people in the industry is 5150 made in China. We use it on some of our cores we buy. I think it all come from the same place. The differences in the finished cams could be in the heat treat process but mainly it is in the finishing and final detailing process.

 

Thatshow my cammmotion cam looks

 

Kip,

Thanks for the response.

I know someone in the industry and they buy the blanks in bulk. It's a crate load that I believe has 1000 cores in it.

I was not given quite the explanation that you provided on the available cores.

 

Wow, great info, thanks Kip!

 

8620 solid roller Comp Cams core we have here at the shop.

 

Nice ! Martin, can you tell us how much the up-charge is to get a 8620 core from Tick ?

 

Our grinds from Cam Motion in 8620 are 460.00 dollars and we offer free shipping as well. From Comp the price will range as they may not have a roughed in core that is close enough to the desired profile.

This cam being a low volume (high duration/high lift profile) was 575.00 dollars. Keep in mind it is 262/279.715/.704 114 so it's not a high volume type camshaft. Smaller grinds in higher volume would be around 475.00-525.00 dollars from Comp.

 

Seems like a no brainer to me...

 

The cam above was $411.79 to my door and was custom ground to my specs by comp cams.