Jim,
+1 on what Brent said about modern pistons and suppliers. My engine is supercharged and my pistons have very small compression heights which means it beats up the piston skirts. Add to that the fact even with the stock stroke more piston that I would prefer comes out the bottom of my cylinder bores at BDC.
When I used the typical aftermarket pistons from all the usual suspects they consistently had thinner skirts than I preferred and would collapse within the first year of use. I ended up going to a predominately race piston manufacturer that builds their pistons from a pure billet of 2618 aluminum stock.
We initially built the pistons in Solidworks, using a finite element analysis software tool to reinforce the highly stressed areas and remove material from the lower stress areas. There was a fair amount of effort involved because of the blower. Naturally aspirated pistons operated below 7000 rpm are a much easier puzzle to solve. BTW although my case was a special (don't we all think our cases are special
) no one but Gibtec would build the piston in Solidworks and noodle out the design for me or with me.
When we were done my pistons, H-13 heavy wall tool steel pins, and TotalSeal rings came in equal to or less expensive than a "custom piston" from any of the highly rated usual suspects. Like Brent suggested good practice for most firms dictates they use and preserve a job card for every set they make.
They will produce the pistons in 0.001" increments (which really saves expensive blocks) and if you need a replacement (you should of ordered ten but ...) they can turn around a single piston that will exactly match the old piston right down to the gram weight — which in the bigger picture is not that surprising because each piston is a CNC machined original.
The company typically builds for the NHRA pro classes (T/F, F/C and P/S along with the Pro-Mods). If you are interested in investigating what is possible, the company is Gibtec Pistons and if you want, I will introduce you to the design engineer who built the blower pistons for me. BTW those pistons were about 10 or 15% lighter than any aftermarket blower pistons form any of the usual suspects. More important to me they have easily survived four plus years for me and guys I have built blown engines for.
N/A will not work the pistons as hard and you might say why do I need to go to a piston at that level. The answer is simple reliability, consistency, strength, quality and they are the same price or less than pistons from the usual suspects.
If you want an intro let me know by PM and I will help. BTW full disclosure I have no financial interest in them and receive no form of any type of compensation from them. Like Brent, they are just real good guys with a real good product that are easy to work with and helped me when no one else could.
Ed