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Recent advancements in the combustion control of new generation engines can benefit from real time, precise sensing of the cylinder pressure profile to facilitate successful combustion feedback. Currently, even laboratory-grade pressure sensors can deliver pressure traces with insufficient signal-to-noise quality due to electrical or combustion-induced signal interference. Consequently, for example, calculation of compression and expansion polytropic indices may require statistical averaging over several cycles to deliver required information. This lag in the resultant feedback may become a concern when the calculated combustion metric is used for feedback control, especially in the case of transients. The method described in this paper involves a special digital filter offering excellent performance which facilitates reduced-error calculation of individual polytropic indices.

Wavelet transform analysis is capable of revealing aspects of data that other techniques miss such aspects are trends, and discontinuities in higher derivates. This method can often compress or de-noise a signal without any appreciable degradation and it provides accurate information on the localization of energy content in time and frequency [1]. The Wavelet transform method has been applied to the analysis of combustion noise and piston slap in order to identify the effects on the engine structure vibration. The experimental results showed that combustion noise and piston slap were successfully detected from the acceleration signals picked up by external transducers in the outer wall of an in-line, 6 cylinder diesel engine.

The paper covers highlights of SAE activity on emissions control from the early efforts of Campbell and others in the 1930's to the present time. Evidence of substantial involvement in the Los Angeles “smog” composition led to the development of analytical tools for continuous evaluation of exhaust. With these tools and other basic information, it became possible to develop many control devices. Over 20 of these devices have been added as standards have tightened. The negative result has been increasing cost and complexity. The crankcase and evaporative systems have been controlled, but the principal emissions have come from the exhaust, and therefore most of the controls were directed to this source. Combustion within the engine has been the principal area of attention, but when this did not meet the requirements of the existing statues, combustion beyond the exhaust ports became important. Notable contributions to this art were air pumps, afterburners and catalysts.

Karanja biodiesel is prepared using Karanja oil and methanol by the process of transesterification. Use of Karanja oil methyl ester (KOME) in a 780 hp CIDI military engine was found to be a highly compatible alternative fuel with low emission characteristics. Engine was operated for 100 hours each using pure karanja biodiesel and mineral diesel fuel, respectively. These were subjected to long-term endurance tests. Lubricating oil samples, drawn from both fuelled engine after a fixed interval of 20 hours, were subjected to elemental analysis. Atomic absorption spectroscopy (AAS) was done for quantification of various metal debris concentrations. Wear metals were found lower for a biodiesel operated engine system. Lubricating oil samples were also subjected to ferrography indicating lower wear debris concentrations for a biodiesel-operated engine. Scanning electron microscopy was also conducted on the cylinder liner surfaces exposed to wear.

Since wear is a not a material property, but a tribological system property, it is of great importance to know the wear, friction and lubrication behavior of materials tested in bench equipment. This work presents reciprocating pin-on-plate bench tests results, with gas nitrided stainless steel pins and gray cast iron plates. The testing conditions were 0.5 and 3.2 Hz frequency, 20 and 600N applied load and 100 and 150 °C. Under these conditions, mild to severe wear transition was observed. It was noticed noise emission changes at wear transition. This noise change could be used to verify wear transition mechanism.

Three 1978 Ford Pinto 2300 cc vehicles were retrofitted to operate on neat methanol and driven for an 18-month period. The modification package included carburetor rejetting, upgraded fuel filtration and electric cold start assistance. Internal engine components (excepting camshafts) and the engine lubrication system were not modified. A conventional motor oil was used in all vehicles. Over 30,000 vehicle miles were accumulated in the test period. Wear metal samples were taken at 1000-mile intervals and analyzed for 16 metallic constituents using Direct Reading Emission Spectroscopy (DRES). Percentage fuel and water dilution were also measured. All oil samples showed abnormally high concentrations of lead and tin. Iron accumulation rates over the entire test were similar to those reported for gasoline engines. Maximum fuel or water dilution in any sample was 0.5%.

The mechanism of overhead valve train wear in moderate to low temperature service was studied using a modified fired V-D test and a motored V-D cam and cam-follower rig. High wear and Sow wear used oils from the fired test gave the correct relative wear in the motored test, indicating the motored test is a valid tool for studying wear mechanisms. Key factors affecting valve train wear were isolated and selectively introduced in a series of motored engine tests. Results from this study showed the expected increase in wear with a decrease in viscosity of unformulated lubricants. Added zinc diaikyldithiophosphate (ZDDP) reduced wear in a low viscosity lubricant and a used oil as anticipated. A high detergent, high wear oil, in an unused state, did not produce significant wear in the motored test even if all of the ZDDP was removed. Significant wear resulted only after exhaust gases (simulated blowby) were fed into the motored engine sump containing the high wear oil.

Three pairs of cars were each driven over 80 000 km at predominantly highway speeds and summer ambient temperatures. One car of each pair used an SAE 0W-30 partial-synthetic motor oil, and the other used an SAE 10W-30 all-mineral motor oil. These oils were of similar chemistry. The test has demonstrated that the low viscosity, SAE 0W-30 oil offered comparable performance to the SAE 10W-30 oil, in terms of engine wear and cleanliness. Excellent connecting rod and main bearing wear, and valve train wear protection was observed for both oils, even though their viscometric properties at high temperatures and under high shear rate conditions are less than the minimum proposed by some engine manufacturers and researchers.

SEVEN HUNDRED tons of iron, estimated by the authors to be worn annually from the cylinder bores of American automotive engines, cause an annual engine repair bill believed to exceed $1,000,000,000. A large part of this wear is due to corrosion, particularly in severe service such as gasoline-powered delivery vehicles or stationary diesel installations. Test results indicate that wear rates can be materially reduced by the use of crankcase lubricating oils containing high concentrations of alkalinity. The authors also present examples of radiochemistry research. Radiotracers are used to prove that oil consumed by the engine carries with it the iron debris which it contained at the moment of consumption.

Automobile component particularly the engine cylinder is subjected to continuous wear during the running of the automobile specifically the two wheelers. Aluminium alloys are the material of choice due to their high strength/weight ratio. As aluminium alloys have poor wear and corrosion resistance, a uniform wear resistant composite coating is required on the bore of the internal combustion engine cylinder. There are several methods to produce composite coatings like chemical and physical vapour deposition, plasma spraying, metal infiltration, powder metallurgy etc. Ni-SiC coating commercially known as NIKASIL, is the most commercially used coating in automobile’s/aero IC engines. However, SiC tends to react with the nickel matrix at temperatures above 400 °C forming a brittle nickel silicide which deteriorates the performance of the coating. Also, the synthesis of SiC particles utilizes high energy.

This paper presents wear results of the top piston ring for an automotive spark ignited engine using gasoline and methanol blends. The Radiotracer Technique was employed utilising the multichannel analyser. In order to assess the wear process resulting due to each single factor viz. fuel type, engine speed, bhp and the water jacket temperature, investigations were carried out based on a series of statistically designed experiments. The design matrix employed a one half replication of 24 set. The study showed that the speed and load of an engine markedly affect the top ring wear. Use of alcohol blended fuels was found to marginally increase wear especially at low operating temperatures.

Axial piston type pumps are often exposed to severe operating conditions because of the duty cycle, the environment, or, in some situations, poor maintenance and even abuse. The detrimental effects on the pump and the hydraulic system as a result of these adverse conditions are often not known or predictable. In this study, four controlled severe operating conditions were imposed on four identical axial piston type pumps. They included 1) constant high load pressure and normal fluid temperature, 2) constant high load pressure and elevated fluid temperature, 3) cyclic load pressure and normal fluid temperature, and 4) cyclic load pressure and elevated fluid temperature. The tests were long-term; they were run continuously for up to 5000 hours. The pump wear was monitored in all cases using ferrography. In addition, the condition of the fluid was monitored and the circuit filters were examined periodically. The results of the findings are presented in this paper.

Sliding wear of magnesium (Mg) engine cylinder bore surfaces and corrosion of Mg engine coolant channels are the two unsolved critical issues that automakers have to deal with in development of magnesium-intensive engines. In this paper, Plasma Electrolytic Oxidation (PEO) process was used to produce oxide coatings on AJ62 Mg alloy to provide wear and corrosion protection. In order to optimize the PEO process, orthogonal experiments were conducted to investigate the effect of PEO process parameters on the wear properties of PEO coatings. The PEO coatings showed a much better wear resistance, as well as a smaller friction coefficient, than the AJ62 substrate. The galvanic corrosion property of AJ62 Mg coupled with stainless steel and aluminum (Al) was investigated via immersion corrosion test in an engine coolant. Applying PEO coating on Mg can effectively prevent the galvanic corrosion attack to Mg.

Wear characteristics of four bearing materials have been investigated under different sliding conditions. The bearing materials used were CDA 954, CDA 863, CDA 932, and CDA 938. Using a Taber Wear Tester, a cylinder on a flat geometry was used as a tribo contact pair. All bearing materials in the form of a thick cylindrical disk were subjected to combined sliding-rolling motion against a rotating flat disk. The flat disk was either an abrasive disk, or a very soft steel disk, or a hardened steel disk with and without lubrication. Wear was measured as weight loss after several thousand cycles of rotation. Maximum wear of the bearing materials occurred when the counter body was a very soft steel disk. These results together with the wear rate of each bearing material sliding against four different counter bodies are presented. These results are found to be of practical importance in the design and application of journal bearings made of materials used in this investigation.

The characteristic wear of electroplated chromium on piston rings has changed over the past 15 years. The reasons for the change are discussed and a theory proposed for the wear mechanism. The theory is supported by engine test results, radioactive ring and cylinder studies, and metallographic exhibits.

A new bench tester for laboratory simulation of piston ring and cylinder wear has been developed. Tests are made using liner segments which bear against a reciprocating piston ring. Temperatures up to 550°C, and loads and speeds representative of the most severe top ring conditions may be imposed. A precision oil spray system delivers the desired quantity and quality of oil to the wear interface. The computer controlled simulator duplicates the desired test cycle, and displays and stores data on friction forces and friction coefficients as the test proceeds. In this paper results are presented from the simulator for production and prototype ring and liner combinations, including ceramic coatings for potential use in advanced diesel engines. The importance of the method of oil delivery on test repeatability is emphasized. Some comparisons with Cameron Plint bench tests and firing engine results are presented.

A study has been carried out to investigate the influence of soot contaminated automotive lubricants in the wear process of engine valve train contacts. Previous research on this topic has been performed from a purely generic and theoretical point of view. Testing has been carried out using standard testing techniques with very little relevance to real engine conditions or components. In this study the conditions under which wear occurs was investigated using tests with actual valve train components. The objective of the work was to develop a knowledge base of wear data for a variety of lubricated reciprocating valve train components. This will increase the understanding of the wear mechanisms that occur within a contaminated contact zone, which will be used in the future development of a predictive valve train wear model.

SEVERAL factors are involved in the answer to the question, “How do atmospheric conditions affect the ability of a fuel to satisfy the antiknock requirement of automotive engines?” As is well known, an increase in atmospheric temperature increases the octane-number requirement of engines. This paper points out, however, that this causes little change in the road octane-number ratings of commercial fuels. Increasing the absolute humidity has the opposite effect to increasing the temperature and tends to counteract the undesirable effects of changing temperature throughout the various seasons of the year. Increasing the barometric pressure or decreasing the wind velocity both increase the tendency of commercial fuels to knock. Factors indirectly related to weather conditions, such as the coolant or thermostat used in an engine, also affect the knocking tendency of a fuel.

Spacecraft radiators reject heat to their surroundings. Radiators can be deployable or mounted on the body of the spacecraft. NASA's Crew Exploration Vehicle is to use body mounted radiators. Coatings play an important role in heat rejection. The coatings provide the radiator surface with the desired optical properties of low solar absorptance and high infrared emittance. These specialized surfaces are applied to the radiator panel in a number of ways, including conventional spraying, plasma spraying, or as an appliqué. Not specifically designed for a weathering environment, little is known about the durability of conventional paints, coatings, and appliqués upon exposure to weathering and subsequent exposure to solar wind and ultraviolet radiation exposure. In addition to maintaining their desired optical properties, the coatings must also continue to adhere to the underlying radiator panel.

We assessed the feasibility of weight reduction concerning noise and vibration characteristics for engine components. Three alternatives were plastic intake manifold, stamped steel oil pan, and no balance shaft. The assessment indices were engine noise level, engine mount bracket vibration, and engine block vibration. Reducing the reciprocating mass and applying design alternatives made the removal of balance shaft feasible. The lightweight plastic intake manifold was beneficial to the engine vibration with a little improvement to the engine noise. The stamped steel oil pan, with optimal structural ribs design and EMS calibration, offered all the benefits of weight, vibration, and noise improvements.