PENGARUH CELAH CAMSHAFT TERHADAP NOISE PADA CYLINDER HEAD HONDA CB 150 R

Noise on a motorcycle is unwanted sound because it does not fit the context of space and time thus affecting ride comfort . Noise caused by the vibrating object or objects collide . Which became the main object causes of noise in the Cylinder Head Honda cb 150 R is due to the large gap camshaft causing collision between the camshaft with holder. This research was conducted entirely in the workshop by examining the influence of several variations of the gap camshaft to noise generated in the cylinder head . Variations slit used was 0,75 mm , 0,85 mm , 0,95 mm , 1,05 mm, and 1,15 mm . The results showed that the variation of the gap camshaft significant effect on the noise generated , namely : a gap of 0,75 mm camshaft generate noise by 78,12 dB , 0,85 mm gap camshaft generate noise with a value of 78,37 dB , 0,95 mm gap camshaft generate noise 78,93 dB , 1,05 mm gap camshaft generate noise levels at 79,95 dB, and 1,15 mm gap camshafts produce 80,23 dB. Based on the results of the research with camshaft gap variation can be concluded that the lowest noise level generated by the camshaft gap of 0,75 mm .

Evaluation of the partitioned mechanical properties and the hall-petch relationship of cast aluminum alloy cylinder head

In view of the non-uniform distribution of mechanical properties of cast aluminum alloy cylinder head, the mechanical properties evaluation and microstructure heterogeneity of cylinder head were studied. The results showed that the head plate position of the cylinder head has the best mechanical properties and microstructure characterization, followed by the floor plate and the thick partition plate. The mechanical properties of the floor plate position attenuate with increasing temperature. From 23°C to 300°C, the tensile strength and yield strength decrease in the same range, but the break elongation changes most obviously. The mechanical properties and microstructure characterization of cylinder head in-situ sampling satisfy the Hall-Petch relationship. If the required ultimate tensile strength is not less than 255MPa, the upper threshold of the grain size, by considering the error limit of the Hall-Petch relationship, is 603.4μm, and the upper threshold of secondary dendrite arm spacing is 69.1μm. Meanwhile, established the relationship between hardness and yield strength, the average error of the nonlinear model is 4.35%. The prediction accuracy of the nonlinear model is sufficient to meet the actual needs of the engineering.

Hydrogen Containing Nanofluids in the Spark Engine’s Cylinder Head Cooling System

The article is devoted to the following issues: boiling of fluid in the cooling jacket of the engine cylinder head; agents that influenced the thermal conductivity coefficient of nanofluids; behavior of nanoparticles and devices with nanoparticles in the engine’s cylinder head cooling system. The permissible temperature level of internal combustion engines is ensured by intensification of heat transfer in cooling systems due to the change of coolants with “light” and “heavy” nanoparticles. It was established that the introduction of “light” nanoparticles of aluminum oxide into the water in a mass concentration of 0.75% led to an increase in its thermal conductivity coefficient by 60% compared to the base fluid at a coolant temperature of 90 °C, which corresponds to the operating temperature of the engine cooling systems. At the indicated temperature, the base fluid has a thermal conductivity coefficient of 0.545 W/(m °С), for nanofluid with particles its value was 0.872 . At the same time, a positive change in the parameters of the nanofluid in the engine cooling system was noted: the average movement speed increased from 0.2 to 2.0 m/s; the average temperature is in the range of 60–90 °C; heat flux density 2 × 102–2 × 106 ; heat transfer coefficient 150–1000 . Growth of the thermal conductivity coefficient of the cooling nanofluid was achieved. This increase is determined by the change in the mass concentration of aluminum oxide nanoparticles in the base fluid. This will make it possible to create coolants with such thermophysical characteristics that are required to ensure intensive heat transfer in cooling systems of engines with various capacities.

Near-component testing of materials for cylinder heads to determine thermomechanical fatigue under superimposed high-frequency mechanical loads

Due to higher combustion chamber temperatures and pressures in efficient combustion engines, both the high-cycle and thermomechanical fatigue loads on service life-critical components, such as the cylinder head, are increasing. Material comparisons and analysis of damage behavior are very expensive and time-consuming using component tests. This study therefore develops a test method for cylinder head materials that takes into account the combined loading conditions from the above-mentioned loads and allows realistic temperature transients and gradients on near-component samples. The near-component cylinder head sample represents the failure-critical exhaust valve crosspiece and is tested in a test rig specially designed with the aid of conjugate heat transfer simulations. In the test rig, the sample is subjected to thermal stress by a hot gas burner and to mechanical stress by a high-frequency pulsator. Optical crack detection allows permanent observation of fatigue crack growth and crack closure during the test. Fractographic and metallo-graphic examinations of the fracture areas as well as analyses of the damage patterns show that loads close to engine operation can be set in this way and their influences on the damage can be monitored.

Reverse Engineering of Research Engine Cylinder-Head

The pursuit of increasing the efficiency of internal combustion engines is an ongoing engineering task that requires numerous research efforts. New concepts of injection or combustion systems require preliminary investigation work using research engines. These engines, usually single-cylinder, make it possible to isolate a single variable in a complex combustion mixture preparation process, thus enabling analysis of the changes being made. However, these engines are relatively expensive and their designs are offered by a limited number of manufacturers. The authors of this paper have successfully undertaken the engineering task of modifying an existing research engine cylinder head in such a way as to implement an electronically controlled variable valve timing system of the intake system. The process of reverse engineering, together with design assumptions that finally contributed to the construction of the assumed solution has been described in this paper.

Rancang Bangun dan Uji Performansi Alat Pembuka Katup Menggunakan Mekanisme Tuas

<p><em>The increasing number of vehicles every year provides opportunities to vehicles service. Vehicle components that often serviced or overhaul is the valve mechanism. How to remove the valve from the cylinder head generally use a manual valve remove tool. The time required to remove the valve using the tools need a long time. Effort to overcome these problems is to modify the existing valve remove mechanism. The purpose of this research is to design and test the performance of valve remove using lever mechanism. Performance test was conducted to determine the press force value to remove the valve, the percentage increase performance and time to remove the valve. The main components of the valve remove tool using the lever mechanism is frame, table, pole support, locking, hand grips, hydraulic, lever pusher and shaft sled. Testing using the valve mechanism is contained in the cylinder head Toyota Kijang 4K. The valve remove tool design has a simple form, easy to make, cheap, but has very good performance. The smallest of the press force to remove the valve is 129 N obtained at a distance of lock and poles support as far as 22 cm. The valve remove tool using the lever mechanism was design can remove the valve from the cylinder head in time 26,17 seconds/valve or 418,67 seconds to remove 16 valves on the cylinder head. This tool is able to improve the performance of manual valve remove tool screw type by 76,28%, and can improve the performance valve remove tool the pneumatic system by 65,79%.</em></p>