5 Ways To Check Deformation Of Diesel Generator Cylinder Head

Diesel generator cylinder block and cylinder head have different maintenance methods due to their different deformation positions and degrees. The commonly used maintenance methods are as follows.

1. The protrusions near the screw holes on the cylinder body can be smoothed with oil stone or finely filed.

2. The cylinder and cylinder head of diesel generator are not flat, which can be repaired by milling and grinding.

When using the milling method to repair the upper surface of the cylinder block, always take the main bearing hole and the center line of the cylinder hole as the processing and positioning reference. The upper end face of each cylinder can be repaired up to 2 times, and the amount of each repair shall not exceed 0.25mm, and the amount of grinding shall not exceed 0.50mm.

After grinding the upper platform of the cylinder, check the cylinder height H of the cylinder (that is, the distance from the center of the crankshaft main bearing hole to the top of the cylinder), and its value should be within the allowable range. All kinds of engines have different values, so read the manual carefully when servicing.

At the same time, after grinding the surface of the cylinder body, in order to maintain the normal clearance between the piston and the valve and the original compression ratio, a thicker cylinder head gasket should be selected.

3. The cylinder block and the cylinder head of the diesel generator are not uniform. You can also use a shovel to level or apply a slurry, and put the cylinder head into the cylinder block to fasten and grind.

4. The cylinder head is twisted, which can be corrected by tapping method. The method of repairing the cylinder head of an internal combustion engine by knocking and pressing: First, place a steel sheet gasket with a thickness of about 4 times the deformation of the cylinder head between the cylinder head and the flat plate. Press the pressure plate on the center of the cylinder head, tighten the bolts so that the center surface of the cylinder head is connected to the flat bottom, tap the cylinder head with a small hammer 2~3 times, and move the pressure plate to 1/3 of the length in 5 minutes, in order to reduce the internal stress caused by compressive deformation. Then move to the other end of the 1/3 position for pressure correction and hitting.

When the cylinder head is warped diagonally, the pressure plate should be obliquely pressed against the cylinder head. If the pressure calibration is excessive, it can be eliminated by baking the cylinder head next to the forge oven for a while.

5. After the plane of the cylinder head is warped, it can also be trimmed by grinding.

After the cylinder head is ground, the thickness of the cylinder head will be reduced, the volume of the combustion chamber will be reduced, and the compression ratio will be increased, which will lead to the explosion of the internal combustion engine. Therefore, when the thickness of the cylinder head is less than the standard thickness of 2mm, a new cylinder head should be replaced, or an additional cylinder head should be added to continue use if the strength has little effect.

After the cylinder head is ground and deformed, it is easy to produce uneven combustion chamber volume differences, and the difference in volume changes is generally not greater than 4% of the average volume of each combustion chamber of the same internal combustion engine. The volume of the combustion chamber of an ordinary internal combustion engine shall not be less than 95% of the original specification, otherwise it is easy to explode. Therefore, after repairing the cylinder head, the combustion chamber volume should be measured.

Determination of combustion chamber volume. Put the polished cylinder head on the workbench, fully remove the carbon deposits and dirt during the combustion process, and inject a certain amount of diesel into the tested combustion chamber. Stop pouring when the liquid level rises and just touches the upper cover glass plate, and then observe the volume reduced by the measuring cup, which is the volume of the combustion chamber. In the future, it should be compared with the nominal volume of the combustion chamber of this model, if the volume cannot be reached, it should be corrected.

Guangxi Dingbo Generator Set Manufacturing Co.,Ltd. was founded in 2006, as a wholly-owned subsidiary of Guangxi Dingbo Generator Set Manufacturing Co.,Ltd, it is one of the earliest manufacturers of generator sets in China. Dingbo Power has long-term technical advice for users, free debugging, free maintenance, free training services. For more details, please contact us with sales@dieselgeneratortech.com