The noise generated by piston slap in a 6V engine has been measured and modeled analytically using a mobility analysis. The mounting of the cylinder liner in the block has been determined to be an important parameter in controlling piston slap noise in this engine. A method of mounting the liner was developed which reduces the transmission of vibration to the engine block while maintaining the required sealing of the combustion chamber. A prototype engine has been constructed which incorporates this design and the overall noise reduction has been evaluated. The reduction of piston slap noise by this method has been found to be as good as that achieved by the use of tight-fit pistons with the standard liners in this engine.