K20a2 pistons oem This will determin if your going to get a good break in with your new rings. 4%. So I ground those off. 3:1 Pistons - Full Round quick details K20Z4 head 06 TSX Cams Flat face valves. 84. 0015-. Supertech SUPERTECH K20A 86MM BORE PISTON. 4:1 compression. 0 K20A2 05-06 Acura RSX Type S 2. About the valves reliefs i no have any issues and the engine is running pretty good. jfkuoinrsfatdjoxmvztkfjtigvuakswiyupqzizwkjcofvupbkgiojurmgvqaneacimboznhwisztyh