We've never made cams out of D2 but we have made them from M2, CPM42 (all at Hrc 60 to 64), the "cast carbide plus graphite laced" Proferal, chilled iron plus the major PITA H/F welded 8620 and 5160 and flame hardened 4150. There are were others but I can't recall them all or, perhaps can't adimit to anything specific. The H/F was welded with Wahl-Colemanoy 5, 6 or 56 "stellite" material - as difficult at this was, it was not our most challenging effort - we had some 8620 carb and hardened to 63+ that really gave us fits as strange as that may seem.
Essentially, each cam alloy needs/wants its own specifice abrasive to both cut/shape the part. Then, perhaps a different one is needed to finish grind the part. Due to the size of our machine, we are not blessed with the ability to grind with CBN. However, we've used ceramic, silicon carbide, aluminum oxide, plus various "blends" of abrasives not the least of which was a "plastic bond" on one particular situation.
Understandably, we don't/can't talk specifics, especially in the rare instance when we discuss grinding processes. I can say, however that we had the grinding engineer from one abrasive company for a problem - he walked in with this "I'll show them" attitude - he walked out with tail between legs. He admitted that he'd never, ever seen the problem we were having at the time and he'd been in the industry for quite some time. Although he didn't have a clue for a solution, we still had to complete the job.
Half dozen calls later and we had wheels offered by a COMPETITOR for trial - he bought wheels from a totally different abrasive company. They worked unbelieveably well. Imagine, a competitor helping out a competitor??? Needless to say, I still buy my wheels from him to this day and I always pay his bills the day they hit my desk.
Semi-related story: I went to have a root canal and the dentist started boring the tooth and was doing so as if he were trying to break concrete. I forced him to stop as it was EXTREMELY uncomfortable. WHen I gained some composure, I asked him "who the hell taught you how to drill tooth enamel?"
He arrogantlychallenged how/why I should know more about drilling teeth than he did (I suspect he was from U of M). To which I responded, "I grind harder, tougher materials than you do each and every day. Moreover, I KNOW that the procedure you're using for grinding tooth enamel must be bogus - anytime the bit chatters like yours is and then has to be jammed into the part in order to remove/cut material, you're doing it WRONG - try doing it like this..." and I then went on to explain him how we cut materials that are far more difficult to cut/grind than tooth enamel.
Imagine his surprise and my immense relief when the drill cut faster and with NO chatter almost immediately when using the suggested method. What had been a miserable, beyond white knucle experience became at least tolerable.
Life is full of shared experiences - some good and some bad. It seems like a waste to have to learn new ones from scratch - it is always good to use prior knowledge whenever one can.
Although I won't/can't share all of my "secrets" at this time due to the pressures of competition, I do plan on retiring one/some day. Perhaps someone will come along before then and want to buy/carry on the business that I/we do.
At that point, I'll make provisions for my successors to be left with all the knowledge that I can ever hope to share. Think how much more they'll be able to do and how much better they'll be if they don't have to rediscover all over what I already learned.
Besides, for some reason, I don't think there is going to be much need for racing cams in the hereafter. If there is, surely, there's enough technology available to assimilate better capabilities than I have now.