In this paper a new method of measuring instantaneous swept volume of internal combustion engine is discussed. The instantaneous volume of reciprocating IC engines change at a predictable rate as a function of angle. In this work a new novel device is used for measuring
the instantaneous swept volume of SI engine. The volume measurement system consists of a cam mounted on the shaft and a suitable device to measure the cam profile.The profile of the cam was designed such that the radius of the cam is a measure of the instantaneous cylinder volume of the engine. To measure the instantaneous swept volume, the instantaneous radius of the cam is required. For this purpose,a non-contact laser displacement sensor is used. The Laser Displacement Sensor (LDS) was positioned firmly in such a way that laser beam continuously traces the profile of the rotating cam. The Laser displacement sensor measures precisely the distance between the cam surface and itself and
converts this distance into an equivalent voltage. The cam profile was made according to the kinematic relationship between radius, connecting rod and angle for the test engine. The cam was made of Acrylic because it is strong,light and easy to cut on a CNC milling machine. The cam surface exposed to the Laser spot has to be made opaque to reflect the laser beam. To improve the data acquisition
accuracy balancing of the cam was done by shifting the centroid of the cam near to its rotating centre. It was done by removal of mass on the heavier side and addition of mass on the lighter side. The mass removal was performed by drilling holes taking care that the strength of the cam is not sacrificed.An experimental setup is created to validate the measurements obtained by this method by comparing with measurements performed with a angle encoder.