US Patent 7856812 Exhaust device of eight-cylinder engine

An exhaust device of an eight-cylinder engine can include first to eighth cylinders and a manifold. The first to eighth cylinders are ignited in that order. The exhaust manifold includes first to eighth upstream exhaust pipes extending respectively from the first to eighth cylinders. The first to fourth midway exhaust pipes can extend respectively from a joined portion of the first and fifth upstream exhaust pipes, a joined portion of the second and sixth upstream exhaust pipes, a joined portion of the third and seventh upstream exhaust pipes, and a joined portion of the fourth and eighth upstream exhaust pipes. A downstream exhaust pipe can connect extended ends of the first to fourth midway exhaust pipes to the ambient atmosphere.