Angular Torque Methodology for Cylinder Head Bolted Joint and Validation by FE and Experimental Work

Abstract

Cylinder Head Gasketed joint is one of the important joint for internal combustion engines. The main function of cylinder Head Gasketed joint is to seal combustion gases, oil and coolant and avoid entering the air into combustion chamber. Preload is applied on cylinder head bolt to avoid the leakages. Excessive preload on cylinder head bolt will cause extra stresses and cylinder bore deformation also increased which reduces the engine performance. Hence, it is very essential to determine adequate and accurate preload on cylinder head bolts. There are different types of bolt tightening methods followed by engine manufacturers as compared to other methods loss of preload and preload variation is less in angle torque method. In this work, Angle torque method for cylinder head bolted joint classical mathematical model is developed to estimate the snug torque and angle torque. Model is validated with FE analysis and experimental work. High performance 3-cylinder diesel engine's cylinder head, cylinder head bolts and crankcase are taken for methodology development, FE and experimental work.