TOMEI - Forged piston kit for SR20DET φ86.5, φ87

Due to factors such as productivity, cost, and the difficulty in specifying the operating environment, it is not possible to manufacture standard pistons with profiles that prioritize gas sealing performance.

Furthermore, the cylinder is manufactured as a standalone cylinder block within the automobile manufacturer's production line, and while it has cylindrical precision as a standalone unit, it lacks cylindrical precision when the cylinder head is attached.

TOMEI recommends dummy head boring when using oversized pistons with the correct profile. This method involves attaching a dummy head to the cylinder to distort it before boring, thereby improving assembly precision and gas sealing performance during engine assembly.