Further more, the top ring groove is surface hardened for wear reduction and protection against acid corrosion at low temperature.
It is very difficult for the conventional slant split type connecting rod to keep the big end bore without deformation caused by wear and cracks on the surface when it works under high combustion pressure and output. In order for the connecting rod to have both reliability and durability without losing good prospect under such working conditions the holizontal split three-piece design (Marine type) is employed. The design allows the big end bearing to be left in tact and to reduce height over the engine when the piston is pulled out for overhaul.
