Matt,
Yes, I have stated my case about the PD engines and their cams.
This thread started with talk of 'billet' cams over 'cast iron' cams. VAG never did install a cast iron cam in any of their PD's as far as I could ever figure. But originally, the early PD's had CAST STEEL cams. We had no issues with the use of those cams, except for it's incorrect profile. However, there are several companies that sold cast iron cams. Some are Chinese and one company that used cast them in the Netherlands. To tell steel from iron apart was easy enough. Strike the Cast Steel or Billet cam and it rings like a bell. The Cast Iron when struck sounds like a cow bell. DINK! We do not recommend the use of any cast iron cams, except in the tried and true ALH/ AHU engines. The smaller width and higher pressures on the PD's require improved cam materials.
Now, the question is, cast steel or billet? One company still is suckering people with the Claimed "BILLET", like is something special. But guess what? The cams that are worth installing are ALL made by the billet process, not because they are particularly better; there really is not a great deal of difference, except the cast steel cam has a directional grain structure, while the billet is a linear grain structure. But the cost of creating a billet cam is probably 2/3rds the price of casting. So, just like cracked rods, the bean-counters at the manufacturing plants are designing your engine. Is it cheaper? DO IT!
So, it's not whether the cam is cast of billet, it's whether it is properly hardened and has a proper profile. The original design of the VW cam was cast steel, but had a solid lifter profile, which is very hard on the cam followers. Add to that, the cam journal's galley hole is inappropriately placed, and the cam followers are not only hammered, but overheated. Bad combination...
As Matt said, there are other issues with wear-prone aftermarket cams, besides materials and proper heat treating. Many of the cams have a large chamfer, which further diminishes the width of an already too narrow lobe, further increasing the loading on the cam. There is one European engine builder, buying cams from an English company, I will leave unnamed. First, the hardness is all over the place (Chinese are famous for lousy hardening techniques) and Euro company actually REQUESTED a larger chamfer! It's an amazingly stupid thing to do! Or maybe they just WANT them to wear more quickly.
Since we began making our own cams, we have had a successful run that we are below .5% loss ratio, excluding 7 cams destroyed by loss of oil or water. We fixed the damaged engines. And the few other cams we replaced. For the thousands we have sold, it has been very successful and over 10 years of production,
We are not the cheapest. I do believe we are the best. If you want the 'cheap cam', we have a really good price on a cam kit, that comes with a warning. It has 24 months and 24,000 mile guarantee. If you want a cam that will last a long time, buy our modified cam with our 3 year, unlimited mile warranty. If you like your vehicle and want it roadworthy for a long time, get the good cam. You won't regret it.
