Carburetor K 135: device and adjustment
Eight-cylinder gasoline engines ZMZ 53 (theiroften referred to as GAZ 53, although this is incorrect) have been used on a huge number of different equipment: trucks GAZ, buses PAZ and KAVZ. Several versions of the engine continue to be produced in our days.
All engines of ZMZ 53 were equipped with a power systemwith a carburetor. In addition to this device, the system included a fuel pump, a tank or a system of fuel storage tanks, filters and pipelines for communication of the system nodes. Below we will consider the general arrangement of the main node of the power system - the vertical carburetor K 135.
This model came in 1985 to replace the model K126. The appearance of the new device was associated with the modernization of the ZMZ engine family. The body of the new carburettor has not changed, in fact only the cross sections of the jets have changed.
On the body was added a vacuum valve fitting for the exhaust gas recirculation system.
Features of the modernized engine
The carburettor K 135 (like K 126) has two chambers,each of which provides a working mixture of 4 cylinders. On older versions of engines there was an intake manifold with crossing channels at different levels. The first chamber fed cylinders 1, 4, 6 and 7, the second - 5, 2, 3 and 8. Carburetor compartments worked in accordance with the order of flares in the details of the motor. Collector of the old type on the photo below.
On the modernized motor the collector was simplified,and each camera was responsible for the cylinders of its block. This decision made the collector cheaper. But there were uneven pressure pulsations in the carburetor K 135. Because of such pulsations, there is a spread in the characteristics of the mixture in different cylinders and at different engine operating times. A new collector can be seen in the photo.
But thanks to new jets still managedto improve the toxicity standards of GAZ 53 engines. Carburetor K 135 provided preparation of more depleted working mixtures, which slightly smoothes out the heterogeneity of the mixture. The new collector and carburetor, together with the new cylinder heads with increased compression ratio and screw walls of the intake channels, allowed to improve the fuel efficiency of the engines by 6-7%. At the same time, the requirements for the octane number of gasoline have not changed.
The carburettor diagram of K 135 is quite simple. In fact, it represents two independent assemblies assembled in one body and united by a common float chamber. Accordingly, there are two dosing systems. They include the main diffuser, in the narrowing of which the fuel atomizer is located. Below is the mixing chamber, the outlet of the mixture from which is regulated by the gas flap.
The flaps have a common axis, which ensures an almost identical volume of air passing through the chambers of the carburetor. The axis of the dampers is tied with the accelerator pedal of the car.
The metering system ensures the supply of fuel inproportional to the incoming air. A key element of the system is a diffuser with a narrow channel. When air passes through it, a reduced pressure is created, depending on the speed of the passing flow. Due to this phenomenon, fuel is taken through the main fuel jet from the float chamber. Access to these jets is possible without dismantling the carburetor and is carried out through screw plugs in the body of the float chamber.
The fuel level is automatically adjustedneedle valve and associated float. On old models of carburettors in the wall of the camera there was a control window. To maintain the composition of the mixture carburetor K 135 is equipped with a compensation system with air braking of the fuel.
At low rpm, the air flow is low and there is a lack of vacuum in the dispensing unit. To ensure the operation of the engine in this mode, an idling system is used.
For the most complete implementation of engine powerand dynamic acceleration carburetor K 135 is equipped with an economizer and an accelerating pump. Of the additional systems, it is worth mentioning the starting device and the motor speed limiter.
This element of auto is quite simple in constructionand does not require much attention when used properly. Adjusting the carburetor K 135 includes setting the starter, monitoring the fuel level in the chamber and setting the idling system.
When adjusting the start device,close the air damper, which through the pull rod will transfer the throttle of the gas to the starting position. The clearance between the gas flap and the wall of the chamber should be within 1.2 mm. The adjustment of the device consists in setting this parameter and is carried out by means of an adjusting bar in the damper drive. Easy start of the cold engine is possible only with the specified clearance.
Another important stage of adjusting the carburetor K135 is the leveling of fuel in the float chamber. To do this, measure the distance between the float and the plane of the lid. It should be 40 mm. Measurement is carried out on the removed cover in an inverted state. The adjustment of the distance is made by bending the needle of the valve needle drive. In this case, it should not have any damage or dents. The final control of the fuel level is made on the installed carburetor.
Disassembly and repair of carburetor К 135is performed when parts are damaged or the device is heavily soiled. However, do not abuse washing and cleaning. After all, there is a risk of clogging the channels inside the carburetor and disrupting the connections.
One of the most frequent operations is flushingfloat chamber. In this case, only easily removable deposits are removed. Dust tightened to the walls should not be cleaned. Deposits in the chamber are a consequence of the poor state of the fuel filtration system. Therefore, cleaning should be combined with the replacement and cleaning of filters.
When disassembling the carburetor should be reversedattention to the condition of the nozzles; if necessary, they should be rinsed. The state of floats (they are of two types - brass and plastic), axes of dampers, accelerating pump are checked. All damaged parts should be replaced with new ones.
Separately control the condition of the surfaces of the mating parts of the hull. If necessary, they are rubbed on the calibration plate.
Upon completion of the work, the carburetor is reassembled, adjusted and installed on the engine.