Compressor for diesel: device

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

Compressometers are used to diagnose the condition of cylinders and pistons in engines. This is one of the types of diagnostic equipment. With this device, you can do it yourself at home to assess the condition of the motor. The diesel compressor has a simple design. The device is a pressure gauge connected to a special adapter in the form of a nozzle or glow plug. Let's take a closer look at what this device is and how it differs from its gasoline counterpart.

Why is a compression gauge so important?

There are several reasons why it is necessary to measure compression in diesel engines. The compression level is measured in order to determine the technical condition of the parts of the cylinder-piston group and valves. Also, with the help of measurements in real conditions, information is obtained on the minimum temperature for starting a cold engine. Compression measurements are made on both gasoline and diesel ICEs. But in the case of the first units, the requirements for indicators are less. With a gasoline engine, small discrepancies in numbers are not always paid attention to - these engine units have their own characteristics that do not affect their overall he alth.

In the case of a diesel engine, all errors matter. Compression is measured more often - its accuracy is important. Any deviations from normal indicators are a signal of malfunctions in the main engine assembly.

Compression is, on the one hand, a physical quantity. Compression characterizes the force of pressure that is created in the combustion chamber. The main condition is that the measurement is made with the power off. During measurements, the crankshaft rotates only with the help of a starter. On the other hand, compression is the level of maximum pressure when the piston is at top dead center.

Device

The compressor for diesel and gasoline is almost the same in design. The device provides a pressure gauge equipped with a shut-off valve and a connecting hose. The device comes with a set of adapters. The measurement process is carried out due to the presence of this valve - thanks to it, the "memory" of the maximum indicators is preserved, which can be recorded only within tenths of a second.

After measurements, the compression value will appear on the pressure gauge dial, which can be used to judge the degree of wear of partsCPG. During the measurements, not only the compression level in each of the cylinders is evaluated, but also their average value.

Types of compression gauges

Distinguish between mechanical devices and more modern electronic devices. Among our motorists, mechanical pointer devices are the most common. Such compression meters are quite affordable, simple in design, and widely used.

As for electronic analogues, these are more complex devices. Naturally, they are sold at higher prices. Often, electronic devices can be found at large service stations that provide professional engine diagnostics.

Operation principle

Compressometer diesel-gasoline works very simply. To start work, the equipment will be connected to the motor cylinder through the hole of the candle or nozzle. Then the pressure created in the cylinder is fed through the open valve to the pressure gauge. At the moments when the pressure in the cylinder decreases, the shut-off valve closes. This happens automatically. Due to the valve, pressure is maintained in the hose or in the tube, which allows you to evaluate the compression performance. After the end of the measurements, the pressure is released by pressing the button.

Difference between a diesel compressor and a gasoline one

At first glance, it may seem that a compression gauge for a diesel engine is no different from its gasoline counterpart. Indeed, visually the design of the two devices is almost the same. The difference lies in a couple of nuances. Yes, the devicedesigned for measuring compression in diesel engines, designed for high pressure - up to 60 atmospheres and above. This is due to the design features of diesel internal combustion engines.

Also, a compression gauge for a diesel engine can only be a threaded one, while a device for working with a gasoline engine can also be a compression gauge.

Graduation

Manometers are calibrated in MPa, kgf/cm2, as well as in bars and atmospheres. On imported models, the scale can be graduated in PSI. This is a pound force per square inch. For greater user convenience, the scale is divided into color segments. On the left is red, which indicates low compression, and on the right is green. It means that the compression is normal. You need to navigate along it.

How to make a device with your own hands

You can purchase a ready-made device. The price of a compression tester for a diesel engine starts from 650 rubles. But at the same time, you can assemble the device with your own hands from what is at hand. Assembly parts are easy to find in a garage or auto parts store.

For assembly you will need a pressure gauge, a valve from the truck chamber, a nipple, several brass threaded adapters, a high pressure hose.

The valve must not be cracked, deformed or otherwise damaged. As for the size, it is often 8 millimeters. If it is bent, it should be leveled and trimmed where it will fit into the camera. The threaded part does not need to be touched. Using a soldering iron on the side that is cut off, solder the nut,and then screw a pressure gauge into it.

Preliminary, a spool is installed in the tube, and a hose is put on it. One end of the hose is sharpened so that it can enter the hole of the candle or nozzle. Using a set of adapters, you will get a universal gasoline-diesel compression tester.

In this case, the spool will play the role of a valve. The maximum pressure that occurs in the top position of the piston will be recorded on the pressure gauge dial. To reset the readings, simply press the spool.

This is the simplest design. But you can make a compression gauge for a diesel engine, which will be no worse than analogues from various manufacturers. In addition, a home-made device will cost much less at a price.

Compressometer "Friend" (diesel)

On the shelves of car dealerships, this universal measuring device is most often found. It is produced at the enterprise OOO Izmerit. Its cost is different, but not more than one thousand rubles. This compression gauge took the ninth place in the "Behind the wheel" rating. Detailed instructions included. The manufacturer provides an unlimited warranty. As for accuracy, it is quite high. The only negative is the check valve. The indications of the diesel compression gauge "Drug" drop to zero in just a few seconds. The valve itself is practically no different from the tire valve. It can be modified a bit to provide an accurate, low cost and versatile solution for measuring compression in a diesel engine.

King-Tool KA-6640N

If "Friend" ranked ninthplace, this universal diesel-gasoline compression tester is at the top of the rankings.

Estimated cost - 1000 rubles. There are no instructions included, but that's not a problem. The set includes a rigid extension, a hose, and adapters along with a quick connector. But the most important thing is the absence of errors. And the valve is more reliable here. Experts recommend choosing it.