Why liner honing

Lacquer probably originates partly due to decomposition of alkaline oil additives and partly due to decomposition at high pressure and temperature. When the fuel oil comes in contact with lub oil of high alkaline content then fuel react chemically with the alkaline of lub oil to form lacquer. Now due to high temperature the compound form burns and volatile part of the compound formed gets evaporated and leaving carbonic hard part.

This hard part when rubbed with piston rings gets break and along with it some particles of liner also breaks leading to wear of liner. You are commenting using your WordPress. You are commenting using your Google account. You are commenting using your Twitter account. You are commenting using your Facebook account. Notify me of new comments via email.

While Fig. The feeder was located over the engine carburetor 18 , in a convergent—divergent nozzle Laval nozzle. The particles were carried from the feeder into the carburetor by a flexible conduct pipe through convergent nozzle At full load operation, road dust was added at a maximum amount of 1.

View of the research stand for accelerated running-in and intensified wear investigations: 1 Cooling system, 2 muffler, 3 system supplying abrasive medium, 4 dynamometer.

Layout of the research stand for accelerated running-in and intensified wear investigations: 1 hydraulic system for additional oil cleaning, 2 system supplying abrasive medium, 3 oil reservoir, 4 hydraulic pump, 5 pressure reducing flow, 6 flow controller, 7 oil filter, 8 , 9 connections, 10 drain, 11 , 12 , 13 cut-off valve, 14 dust feeder, 15 convergent—divergent nozzle Laval nozzle , 16 supply conduct, 17 convergent nozzle, 18 engine carburettor, 19 inlet manifold, 20 engine cylinder, 21 oil sump.

In the first stage, the engines were run in the fired running-in regime for 10 h at 1,—2, rpm and altered load Fig. The full-open throttle speed characteristic and total efficiency of the engines were then checked. The rough engine performance results were reduced to normal conditions, i. All tested engines were disassembled in order to be able to measure P—C device wear for detailed analysis of wear processes [ 37 ]. Similarly to the after-machining analysis, the same 2D contact instrumentation and procedures were used.

At this stage, given the heavy weight of the cylinders 12 kg and the necessity to carry out non-destructive tests on the blind cylinders at a depth of mm each cylinder makes one piece with the head , it was still impossible to perform 3D measurements using Optical Profiling Systems e.

Engine speed and load schedule for the running-in operation a and the intensified wear elementary test b. The engines were re-assembled and run under artificial conditions that simulated increased dustiness of the ambient air. An elementary 3-h lasting effort cycle that combines 2 h and 50 min of the full load working at 2, rpm and 10 min of the idle load Fig. This self-elaborated testing schedule, which included the intensified wear periods under the dusting conditions, ensured statistically the same wear ratio of the P—C device as the h-long durability test of the engine in real flying conditions.

The engine brake tests and established wear measuring procedures were performed again at the end of the whole research cycle. A preliminary analysis of the output parameters collected for all five engines after each stage of the experiment shows noticeable inter-engine distinctions. Variations in the characteristic values of these parameters for each stage were as follows:. The results indicate that the topography of the cylinders of engine no. Engines no. Engine no.

The effort running of the engines caused internal wear and performance deterioration. The changes made to the topography of the cylinder liners throughout the experiments demonstrated the abrasive mechanism of their wear Fig.

No bore polishing areas were observed. Although the measured wear turned out to be rather high, the engine parameters dropped moderately. Statistically, the average power of the five engines after the running-in operation and after carrying out the full test decreased slightly by 2. The same trend was observed for torque mean value, which changed from The fuel consumption increased by 3. Further extensive analysis was carried out to determine more precisely the relationships between the microstructure of the original cylinder liner and the output parameters of the engines.

However, only two of these, Rvq, and particularly A 2, reveal a much stronger correlation with all of the engine parameters analyzed, including total efficiency, fuel consumption, and harmful compound emissions. The pre-testing and mid-testing measurements allowed multiplying and scattering inputs to be obtained for use in an overall statistical analysis of the problem. In this study, the after-machining cylinder liner surface topography was treated as an initial state for post-running-in engine performances, and the mid-stage surface topography become the initial microstructure stipulating the engine outputs after their effort testing.

The relationships between all of the engine parameters analyzed and the most susceptible condition linear triangle area for valleys A 2 are illustrated in Fig. For A 2 ranging from 7. The slopes of the regression lines proved that the engine performed better when the value of the A 2 parameter was higher; inversely, the environmental factors CO and HC emission became significantly worse with increasing A 2.

Because the A 2 parameter determines the volume of oil reserve on the liner surface, these phenomena seem to be directly connected with better lubrication; thus, with high values of the A 2 parameter, there were both lower friction losses and an increased oil consumption problem during engine testing.

Characteristics of engine output parameters versus pre-testing value of cylinder liner roughness parameter A 2 linear triangle area for valleys.

The results of this study demonstrate distinct variations in engine performance due to differences in the initial microstructure of the initial cylinder liner surface. The slope of a linear regression of valley region Rvq and, particularly, the linear triangle area for valleys A 2 are the roughness parameters that should be taken into consideration at cylinder liner surface shaping. There was a very strong—but negative—relation appears between the cylinder liner roughness parameters tested and harmful exhaust emission, including carbon oxide CO and hydrocarbons HC.

These results confirm that with an increased higher cylinder liner surface, the oil retention volume corresponds to the Rvq and A2 parameters and that there is a higher oil consumption and, consequently, a greater emission of CO , HC , and soot [ 8 , 12 ].

This is a limitation for acceptable values of Rvq and A 2 parameters, which must be balanced within an overall cylinder liner manufacturing technology. A number of the findings reported here concerning the Rq and A 2 parameters may be extrapolated to the equivalent areal parameters: the root mean square roughness of the surface Sq and areal triangle area for valleys Sa 2. Additional 3D measurements of the liner surfaces performed at the end of the bench experiments combined with results acquired from other cylinder liner samples, but machined with the same technology, showed a close, nearly linear dependence between them Fig.

Similar convergences can be also found in [ 34 ]. Correlation of equivalent two- and three-dimensional parameters: a linear A 2 and areal Sa 2 triangle area for valleys, b root mean square deviation of the profile Rq and the surface Sq evaluated on the basis of 80 pairs of cylinder liner measurements. Suchecki, A. Google Scholar. Taylor, C. Wear , 1—8 Wiemann, L. Motortech Zeits 32 , 43—49 Santochi, M. CIRP Ann. Article Google Scholar. Jeng, Y. Von Robota, A. MTZ 60 , — Pawlus, P.

IMechE J. Johansson, S. Cisek, Z. Wang, S. ASME J. Nilsson, B. In: 11th Int Colloquium Surfaces, Addendum. Chemnitz, Germany Hill, S. SAE Paper No. Organisciak, M. Jocsak, J. SAE Paper Lejda, K. Haasis, G. Klink, U. Thanks for sharing this useful update about honing with us.

Looking forward to more blogs like this, to help people understand honing machines better! Heavy Fuel Oil Power plant problems and their solutions. Recent Posts. Honing is a well-adapted and widely used cylinder liner surface finishing process. Honing process produces a precision surface inside surface of a cylinder liner by scrubbing an abrasive stone against it along a definite path.

Why honing necessary:. Oil consumption with unwanted of combustion products such as HC-, CO-, CO 2 , NOx gas and particles emission can be controlled by the liner surface topography. It also reduce oil slobber. The honing angle and texture should me such that it will increase cylinder liner working life.

In conventional plateau honing the angle kept straight. Slide honing can generate more ideal plateau on liner surface. Diagonal honing or helical honing is more consistent way. Honing tool:. Honing Machine - The selection of honing machine depends on to the honing process vertical or horizontal honing , honing angle, definite depth of honing, bore diameter, stroke length etc. It should be selected according to the engine manufacturer recommendation.

Honing stones -Normally diamond abrasive stone used but for smoother liner surface SiC ceramic honing stone used. Honing procedure:.