An engine of Zeetor type Z – 6901 of three compression rings is employed in this investigation to accomplish the experimental work. The indicator diagram i.e. P=ƒ(α) is recorded at different engine speeds. The present work elucidates the measurement and indication of gas pressure within the combustion chamber as a function of crank angle. The study contains the prediction of pressure in inter-ring
volume pressure behind piston ring during engine operation.
For verification of a mathematical model a static test rig apparatus is
designed in order to measure the inter-ring volume pressure within the range of compression pressure i.e. 1bar to 33.8bar. The comparison between mathematical and experimental results show good agreement