Exhaust manifold, is connected with the engine cylinder block, the cylinder of the exhaust together into the exhaust manifold, with different lines. The main requirement is to minimize exhaust resistance and to avoid mutual interference between the cylinders. Exhausted too concentrated, the cylinder will produce mutual interference, that is, a cylinder exhaust, just hit the other cylinder channeling did not drain the exhaust. This will increase the resistance of the exhaust, thereby reducing the engine output power. The solution is to separate the exhausts of each cylinder as much as possible, one branch per cylinder, or one branch of the two cylinders, and make each branch as long as possible and independently formed to reduce the mutual influence of the gases in different tubes.
