Effects of Exhaust Manifold Configuration on a Turbocharged Engine Employing Charge Stratification

A standard cast iron manifold and a thermal reactor were tested on a lean burning Texaco Controlled Combustion System (TCCS) L141 engine. The purpose of the investigation was to study the interrelationships between engine, manifold/reactor, and turbocharger; and to evaluate the possible effects of the reactor's presence on fuel efficiency. Increased energy inputs into the turbine, higher compressor pressure ratios, and marginal reduction in exhaust gas CO were observed with the reactor; however, an overall 4.6% derogation in bsfc with the thermal reactor was also observed. This was due to greater pumping losses, as evidenced by consistently lower pressure differential between the intake and exhaust valves.