Diesel engine compression ratio can not be ignored

The compression ratio of a diesel engine refers to the ratio between the total volume of the cylinder when the piston is at the bottom dead center and the volume of the combustion chamber when the piston is at the top dead center. This critical parameter has a significant impact on the engine's performance, fuel efficiency, and starting ability. Each diesel engine is designed with an optimal compression ratio, but over time, due to various factors, this ratio may gradually decrease. Below are some common causes for the reduction in compression ratio and key maintenance considerations: First, the position of the piston at the end of the compression stroke may be lower than expected. This can occur due to excessive clearance in several components. For example, if the clearance between the crankshaft main bearing and the main journal, or between the connecting rod bearing and the connecting rod journal, is too large, it can cause the piston to reach a lower position during compression, thereby reducing the compression ratio. Similarly, if the piston pin and its seat hole have improper fit, it can also lead to a drop in compression. It is essential to maintain these clearances within the manufacturer’s specifications during repairs. Additionally, deformation or incorrect dimensions of parts can contribute to a lower compression ratio. For instance, if the crankshaft is ground without adjusting the eccentricity, the radius of rotation may become smaller, causing the piston to move downward. A bent connecting rod can reduce the distance between the big and small ends of the rod, which also lowers the piston’s position. During repairs, it is crucial to follow proper procedures and ensure that all measurements are accurate. When replacing parts, always check critical dimensions such as the crankshaft's rotational radius, the center distance of the connecting rod’s holes, and the distance from the piston pin seat to the top of the piston. Second, an oversized combustion chamber can also reduce the compression ratio. This may happen if the valve and valve seat are excessively worn, leading to deep seating that increases the combustion chamber volume. In such cases, the valve and seat should be replaced. Another cause could be using a cylinder head gasket that is too thick, either by design or through intentional modification. Replacing it with a gasket that meets the original specifications is necessary. If the piston’s combustion chamber (such as a pit or recess) has been eroded or if an incorrect piston was installed, it can increase the combustion chamber volume. A qualified replacement should be used, and the volume can be checked using the water injection contrast method. Similarly, if the swirl chamber in the cylinder head is damaged or of poor quality, it may result in an oversized combustion chamber, requiring a new cylinder head. It is important to note that while individual factors may not drastically affect the compression ratio, their combined effect can be significant. To maintain the compression ratio within acceptable limits, it is crucial to focus on high-quality repairs, precise measurements, and proper part matching. Whenever a diesel engine experiences difficulty starting, reduced power, or increased oil consumption—despite normal cylinder sealing, valve timing, and fuel supply—it is wise not to overlook the possibility of a low compression ratio. Regular checks and careful attention to detail during maintenance can help prevent such issues and ensure long-term engine performance.

Single Arm Electric Medical Pendant

The electric surgical pendants is convenient, intact, and easy to use to meet the needs of operation. This pendant is a new type of medical equipment used in modern operating rooms. The compact structure and professional design make it possible to rotate 340 degrees, which can reach the health care provider during the operation and impact nothing after it is lifted. The electric Medical Pendant according to different clinical demands, to configure with expert level caring configuration;

Single Arm Surgical Pendant,Single Arm Ceiling Pendant,Single Arm Hospital Pendant,Single Arm Cavascope Pendant

Shandong Lewin Medical Equipment Co., Ltd. , https://www.lewinmed.com