Determine Torque Plate Tightening Torque Strategy to Achieve Low Bore Distortion for Diesel Engine 2022-28-0490

There is a two-step migration in the Indian automotive industry from Bharat stage IV to Bharat stage VI emission norms. This emission regulatory migration demands substantial engineering efforts to design, develop and validate engine, engine components, and complete exhaust after-treatment system. In this context, cylinder bore distortion plays a vital role in engine blow-by, oil consumption, and its effect on DPF ash loading. For Bharat stage VI engines, overall thermal loading is increased which exerts higher mechanical and thermal stresses over the engine and subsequent components. Increased engine bore distortion has ill effects on the engine and after-treatment devices. Reduction of bore distortion helps piston rings to confirm with the bore, which results in low oil passing through rings towards the combustion chambers which finally results in low oil burn off in the combustion chamber.

In the present work, the study was conducted to reduce cylinder bore distortion by 5 trials (details shown in appendix) which include different torque plate honing with changing head bolt torque values, use of conditioned gasket, and repeatability of bolt uses on the bore distortion values. The study resulted in an improvement of bore distortion around 30 % from baseline with specified torque and angle strategy.