Diesel cylinder body positioning method

The invention discloses a diesel engine cylinder position method, which uses the two directions of the two ends cylinder hole external wall to limit the unit's free degree to undertake it has an even cylinder hole processing wall and to limit the main shaft bear-hole position to undertake the processing allowance of the main shaft bear-hole; the unit enters into the processing area after positioned holder; it uses the rani measuring head prepared by the processing center to detect the two sides cam axles blank hole; it adjusts the initial point of the unit coordinate system to achieve the processing allowance of the ram axle hole by the deviation of the cam axles blank hole position. It achieves the correct position to the three main parts.