A gas engine assembly, comprising: a compressor configured to receive a gas from a gas supply system via a first supply line and to compress the gas; a combustion system configured to receive the gas from the compressor via a second gas supply line and to combust the gas and a fuel; a bypass line having a first end connected along the first gas supply path between the gas supply system and the compressor and a second end connected along the second gas supply path between the compressor and the combustion system, wherein a gas flows either from the first end to the second end, or from the second end to the first end in dependence upon a pressure ratio between the first gas supply line and the second gas supply line; and a first sensor located along the first gas supply line and configured to measure one or more parameters of the gas supply; a second sensor located along the second gas supply line and configured to measure one or more parameter of the gas supply; a gas supply control mechanism (162, 164) provided in one or more of the gas supply system, along the first or second gas supply lines (152, 153) or the bypass line and configured to adjust the flow of gas within the gas engine assembly; a control system configured to receive measurements from the first and the second sensors (161, 163) and to determine a transportation delay value of the gas along the first and second gas supply lines (151, 152) based on one or more of the measured parameters and using non-linear algorithm for taking into account a diversion of a portion of gas flow from the first and second gas supply lines (152, 153) through the bypass line, wherein the transportation delay value corresponds to a delay between a time when the gas supply control mechanism (162, 164) is adjusted and a time that a corresponding feature in the gas flow resulting from the adjustment is received at an intake manifold to the combustion system and wherein the control system is further configured to control the gas supply control mechanism (162, 194) based on the determined transportation delay. a compressor configured to receive a gas from a gas supply system via a first supply line and to compress the gas; a combustion system configured to receive the gas from the compressor via a second gas supply line and to combust the gas and a fuel; a bypass line having a first end connected along the first gas supply path between the gas supply system and the compressor and a second end connected along the second gas supply path between the compressor and the combustion system, wherein a gas flows either from the first end to the second end, or from the second end to the first end in dependence upon a pressure ratio between the first gas supply line and the second gas supply line; and a first sensor located along the first gas supply line and configured to measure one or more parameters of the gas supply; a second sensor located along the second gas supply line and configured to measure one or more parameter of the gas supply; a gas supply control mechanism (162, 164) provided in one or more of the gas supply system, along the first or second gas supply lines (152, 153) or the bypass line and configured to adjust the flow of gas within the gas engine assembly; a control system configured to receive measurements from the first and the second sensors (161, 163) and to determine a transportation delay value of the gas along the first and second gas supply lines (151, 152) based on one or more of the measured parameters and using non-linear algorithm for taking into account a diversion of a portion of gas flow from the first and second gas supply lines (152, 153) through the bypass line, wherein the transportation delay value corresponds to a delay between a time when the gas supply control mechanism (162, 164) is adjusted and a time that a corresponding feature in the gas flow resulting from the adjustment is received at an intake manifold to the combustion system and wherein the control system is further configured to control the gas supply control mechanism (162, 194) based on the determined transportation delay.