I'm not understanding.....sorry to post on your thread. I do understand that forged are stronger than the hyper's but why are there so many stroker kits with hyper pistons? Are they selling inferior parts that will not last in a stroker application?
Cast are the weakest. They are light and can take some abuse, but will flex and break in a modrate build. plus, most designs are stock based and simply not that good for a modern build. Hypereutectics are a cast piston. But they are a much different casting process and material. So they are very light, and stronger than a std cast design. But, in that strength are a couple caveats: They are harder, like tool steel vs iron. That means stronger, but much more brittle. They are also much more thermally stable. Meaning they dont expand much when warm so you run the piston to wall clearances fairly tight. Last, they are designed to reflect the heat of combustion back into the chamber. That means in some designs the top ring gets hotter and needs to have a wider ring end gap to avoid the ring ends butting and damage. Forged are the top of the line. But again, different materials and designs. There are some that are very heavy, some that are old designs, and some that are modern in material and design, and pretty light. As each piston gets stronger, it can cope better with the stresses of life in a cylinder. The cast piston will pull apart in a 4" arm engine because it's no strong enough to withstand the speeds above about 4K. A hyper piston will also fail this way if the rpms is high enough. Mathematically that's around 5500. the kits that have them are cheaper, and the hypers are cheaper pistons... You ALWAYS get what you pay for. Or dont get what you save. So for anything with a 3.79 stroke or larger, I wont use a hyper. I do use hypers all the time in factory stroke engines with very good results.