I was curious about the factory h22 piston being forged or not. My initial thought was they are not, but possibly in the frm h22 sleeved block they might be. The only reason I concluded to this was the f20/22c s2000 motor has frm sleeves and forged pistons. If you look at the Honda manual, piston to cylinder wall clearance specs are .0002-.0011 on the h22 & f20c. A forged and cast piston should expand at different rates, no...? Now this seems very tight for forged pistons. (If the h22's are) After market forged piston clearances usually about .0025-.0045 Allowing for growth, depending on size, application, or material content, i.e 4032 or 2618 forgings. These however are used in iron sleeves typically, and the iron does not expand as quickly as the aluminum piston. From my understanding the way Honda can run such tight clearances is due to the frm walls expanding at about the same or similar rate as the piston. So are h22 pistons forged like the s2000? Could you in theory put a h22 piston in a f20c block & vice versa and have same expansion rate/clearances & strength? I realize compression height is different but just theoretical. So is Honda messing around with the silicon content to affect piston growth.. Or is the s2000 piston really not forged? Or is it (semi forged) if there is such a thing. I think there really is a difference due to the factory s2000 pistons costing 3x more than h22 factory pistons. Maybe maybe not. any actual knowledge or insight would be helpful. If I stated anything incorrect please let me know. I don't want to spread false info