| Currently, engine manufacturers design internal combustion engines primarily for use at steady-state operating conditions. Little or no design consideration is made for transient engine warm-up. The research contained herein was driven by the engine designers and manufacturers need for the understanding of friction behavior with the effects of varying engine temperature from ambient to steady-state operating conditions. Using the instantaneous and cycle-averaged motoring torque of a 2.0-liter spark engine, the present of individual engine valve train, pistons and connecting rods, oil pump, and crankshaft assemblies. By analyzing the resulting indicator diagrams, the pumping loss effect of air compression within the cylinder was also determined.; A common criticism of the motoring method is that the engine is unloaded, since ignition is not occurring in the piston cylinder. The innovation offered here to the ignition gasoline internal combustion work determined the friction behavior component assemblies, including the standard method resided in applying a pressurized head to the intake manifold, thereby simulating loading of the engine by raising the cylinder pressure above that generated through normal compression. Another criticism of the standard motoring method is that the engine does not warm, so lubricant temperature and viscosity does not model that of a fired engine. The present research method used external heaters to warm both the oil lubricant and water coolant from 25° to 85°C.; In light of instantaneous and cycle-averaged motoring torque, observations and conclusions were presented as to the effect of engine speed, coolant and lubricant temperature, and loading on total engine losses (friction and pumping losses). Contributions of individual engine losses were examined, as well as temperature. A detailed error determine the goodness of the results and a maximum error of the experimental measurements to reasonably be expected, due to random and bias errors, instrument repeatability, and analog-to-digital converter readability.; The added knowledge of the transient effects of engine temperature, speed, and loading on the total engine losses, can help future designers to mitigate friction and component wear thus improving overall maintenance costs, specific fuel consumption, and emissions. |
