CP pistons began when some employees left JE to make a "better" living. Not that it matters, but it's my understanding that they weren't engineers....
You have to understand that JE's pistons, while not as bad as some others on the market, really aren't machined as precisely as many picky engine builders would like...especially their ring grooves. I stopped dealing with them 18 years ago because they were selling my Nascar designs out the back door.....
CP (as the story goes) had a batch of semi-machined pistons that sat in direct sunlight for several days prior to the final machining of the ring grooves, and that batch of pistons made more power than others that weren't "stress relieved". The ring grooves remained straighter after the pistons were run (heat-cycled) in engines, making their cylinder seal better. Everyone knows that keeping the rings sealed to the cylinders is critical for performance, and that's when CP began using the claim that their grooves were the straightest in the industry in advertising.
I think their (CP) pistons are very nice pieces, and I'm flattered that they've adopted many of the (apparent) design features of our Roller-Waves in their pistons, but I can assure you that their offerings for these small-bore engines aren't superior to our pistons.
Dover (who owns Wiseco and JE for that matter) made a committment that Wiseco's pieces would not be second to any in the industry several years ago. To that end, Wiseco has the best machining equipment in the industry, and they are the ONLY company (of JE, CP, and Arias) that actually forges and heat-treats their pistons in-house. You could take all of thwe companies I just named and they'd all easily fit under Wiseco's roof.....
The only example I've seen where a team claimed that CP's offerings were superior was from a ProStock team a year ago. They claimed that the CP's ring grooves stayed straigher (than Wiseco's) after cycling them. Now remember that this is with pistons that are 4.75" in bore diameter, so they aren't even relative to imports. The team that set the all-time one-year win record (last season) in ProStock (Greg Anderson) uses Wiseco's exclusively, as does Warren Johnson's engine program. Jack Roush also used Wiseco pistons exclusively in all his Nascar engines (and for some less-informed individuals, strutted pistons were developed state-side in the 70's, not the 90's) and while the Ford-forced teaming of the Roush and Yates engine group is using "different" pistons now, secret testing, independant of that program recently showed a 14 HP gain with Wiseco's....
Keep an eye on that shot-gun marriage between those two because it's gonna get interesting.
Back to imports.... with the commitment to maintaining the tightest tolerances and offering the finest parts in the industry, I can assure you that if CP's skirts and ring grooves were better than what Wiseco makes to our specs....we'd be using them.
We make several running-changes to our pistons every year that we don't shout about, but fine-tuning details like the corner radiuses in our valve reliefs, changing cam and barrel-shapes of skirts, etc. continues to make our pistons the best on the market.
I've been designing pistons since 1969 for engines I've prepared and raced, as well as those used in all the NASCAR (and USAC/CART) engines I've worked with and I use all those years of combustion experience in configuring our Roller-Wave pieces. Had I been satisfied with any piston company's offerings, I'd have never designed the first Roller-Waves for use in my own Civic back in the early-mid-nineties. I never planned to get into the piston business at all, but people asked me to develop pistons for their specific applications, and I did. The rest is history...