Design, optimization and manufacture of exhaust manifold for a outboard spark ignition engine

The present study is a numerical and experimental study that investigates the effect of using exhaust smoke extractors as an alternative to traditional manifolds in a spark ignition engine designed to maximize engine power. For this purpose, a specific engine is considered as the base engine and to investigate the effect of the extractors on the engine performance and selection of superior design, the proposed geometric model of proposed manifolds in a numerical simulation process has been investigated and after optimization, the model is simulated by numerical simulation softwares and after verifying the performance improvement, the model has been constructed and installed on the engine. At the next step, the engine was experimentally tested in the test cell. Results were compared with the base engine. It was observed that the designed exhaust extractors would increase the maximum engine power up to 15% That this amount of increasiaton in engine efficiency relative to the required costs, is very significant.