How to Inspect and Replace The Valve Guide of Diesel Generator?

The function of the diesel generator valve guide is to guide the movement of the valve, ensuring that the valve moves back and forth in a straight line, allowing the valve to fit correctly with the valve seat ring, and transferring the heat from the valve stem to the cylinder head.

There are two types of diesel generator valve guides: integral and embedded: the integral valve guide is directly machined into the valve stem hole in the cylinder head; The embedded valve guide is pressed into a cylindrical tube in the guide hole of the cylinder head with an interference of 0.015-0.065mm. This article is about the inspection and replacement methods of diesel generator valve guide tubes, shared by professional diesel generator manufacturer Dingbo Electric.

(1) Inspection of valve guides. When checking, the wear of the valve guide can be determined by measuring the aperture size of the guide tube. However, it is common to insert a new valve into a clean valve guide tube and leave the valve head 3mm away from the valve. Then, use a dial gauge to measure the amount of shaking of the valve squeezed into the guide tube to determine the wear of the valve guide tube. If the shaking force is too large (generally not exceeding 0.18mm), it indicates excessive wear of the catheter and should be replaced.

(2) Replacement of valve guide. After heating the cylinder head to 80-100 ℃, use a punch that is suitable for the size of the guide tube to press the guide tube out of the guide tube hole. At the same time, apply a layer of engine oil on the outer wall of the selected guide tube, and use the punch to punch it into the guide tube hole. After the new guide tube is pressed into the bottom hole of the cylinder guide tube, it is required to maintain a certain distance between its upper end face and the upper plane of the valve guide tube bottom hole of the cylinder head. If the distance is too small, it will increase the intake and exhaust resistance, while if the distance is too small, it will affect the heat dissipation effect of the valve and guide tube.

Before inserting the catheter, check if there is any damage to the bottom hole of the catheter. If there is any damage, it should be enlarged (plated) as shown in Figure 4-23, and replaced with a valve guide with an enlarged outer diameter size.

The valve guides of diesel engines of the same brand may also vary depending on the model, and the assembly dimensions may also vary. Special attention should be paid when replacing them.

For Iveco diesel engines, there are:

1. The interference between the valve guide and the hole is 0.032-0.070mm.

2. After the installation of the valve guide, the clearance between the valve stem and the valve guide should also be checked, which should be 0.023~0.053mm.

3. The outer diameter of the valve guide is 13.012-13.025mm.

4. The inner diameter of the catheter is 12.955-12.980mm.

Dingbo Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to sales@dieselgeneratortech.com we will pay highly attention on your question.