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A thermodynamic simulation model for the 4-stroke cycle of a single cylinder spark ignition engine operating on neat methanol is described in this paper. The development of the model for all the processes is illustrated. It computes the gas pressure, gas temperature and the rate of formation of nitric oxide and carbon monoxide at each crank angle using basic energy equation and reaction kinetic mechanism. A gas exchange model has been formulated by finite difference scheme to evaluate the mass flow rate through valves and the properties in the intake and exhaust systems. The validation of the above model has been carried out by comparing the predicted and experimental data at different operating conditions encompassing changes in fuel-air equivalence ratio, speed, load, spark timing and compression ratio. The special characteristics of methanol such as rapid burning rate, high power output and reduced nitric oxide emissions have been truthfully predicted by the model.

In this paper the experimental investigations relating to the performance and emission characteristics of a single cylinder spark ignition engine operating on a newly designed gasoline fuel injection system are described. This gasoline fuel injection system was operated under port and manifold injection configuration by controlling the duration of injection with an analogue based control system, which uses the information corresponding to engine speed and throttle positions. A comparison between the manually controlled fuel injection system with that of the analogue controlled version had indicated that the overall performance of the analogue base fuel injection system is better than that of the manually controlled system fuel injection.

Experimental investigations relating to the comparative assessment of the performance and emission characteristics of port and manifold gasoline injection systems of a single cylinder four stroke spark ignition engine are described. These investigations have been carried out under carburettor, port injection and manifold injection modes The experiments pertaining to the injection mode were conducted for both the single and double hole injectors by optimising the injection pressure, injection timing and its duration. Optimisation of injection timing and duration was done in terms of engine crank angle by means of a newly designed crank angle selection unit in conjunction with a developed optical crank shaft encoder capable of generating pulses at one degree crank angle intervals.

Experimental investigations relating to the performance and emission characteristics under idling conditions of a three cylinder passenger car spark ignition engine operating on a conventional carburettor and a developed single point gasoline fuel injection system are described in this paper. The idling performance at different engine speeds was studied by carrying out comprehensive engine testing on a test bed in two phases. In the first phase, experiments were conducted on an engine fitted with a conventional carburettor whilst they were extended to the engine provided with a developed electronic single point fuel injection (SPI) system, whose fuel spray was directed against the direction of air flow. The injection timing of the SPI system was varied from 82 deg. before inlet valve opening (or 98 deg. before top dead center) to 42 deg. after inlet valve opening (or 26 deg. after top dead center).

This paper describes the experimental investigations on a single cylinder, two stroke spark ignition engine in the carburettor and in-cylinder injection (GDI) modes. The experiments were conducted on the engine in the carburettor mode up to 80% throttle opening and for different combinations of speed and load. The engine was modified and fitted with an in-cylinder injector in the head. Fuel was supplied through injector with the help of a high pressure DC pump. Experiments for varying speed and load were conducted under in-cylinder injection mode up to 80% throttle opening. It was observed that there is a significant reduction in BSFC, unburnt HC and CO emissions. Also, the power output of the engine has shown an improvement.

Experimental investigations relating to the use of producer gas in a spark ignition engine are reported in the proposed paper. The experimental setup consists of a single cylinder diesel engine converted to operate on a spark ignition engine mode coupled to a swinging field electrical dynamometer. A downdraft closed top charcoal gasifier has been used to generate the producer gas. After cooling and cleaning, it is fed to a venturi type gas carburetor, which ensures proper mixing of gas and air before it enters the engine. Testing of the converted engine was carried out under gasoline mode at a specified compression ratio. However subsequent tests on producer gas operation were performed at different compression ratios. The significant outcome of the present investigations include the satisfactory conversion of diesel engine to a spark ignition mode for neat producer gas operation and satisfactory operation of gas carburetor designed and developed for the purpose.

Performance, combustion and emissions investigations relating to the use of gasoline injection in a spark ignition engine are described in this paper. The engine used for experimental purpose is a motorcycle engine of 13.4 kW (18 HP). Experimental engine test setup is designed to operate in carburetion as well as in injection mode [1]. Electronic controlled throttle body injection system is designed to operate test engine in injection mode. This paper also present the procedure used for gasoline fuel injection optimization and discussed the results obtain for minimum fuel consumption, for maximum power and for minimum brake specific fuel consumption, for optimization of the start of injection (i.e. injection delay), injection duration and injection pressure, for the entire operating range, of the research engine used for investigation.

A method of measuring exhaust velocity with respect to crank angle in a 4-stroke spark ignition engine is described as is a new method of automatically selecting a crank angle in an engine under running conditions. The method of obtaining the exhaust velocity, using the selected crank angle, is also dealt with. The exhaust velocity measured for both motoring and firing conditions is included. The results provided for the firing conditions include different exhaust configurations. The cycle-to-cycle fluctuation is also provided for the above configurations.

Performance, combustion and emission characteristics relating to the use of 20% methanol and 80% gasoline in a spark ignition engine are described in this paper. The engine used for experimental purpose is a motorcycle engine of 13.4 kW (18 hp). A new online multi liquid fuel mixing system has been developed for perfect mixing and hence found to be better for investigating effects of Methanol - Gasoline blend (M20) which enhances engine performance and reduces exhaust emissions. Performance tests conducted under Throttle Body Injection (TBI) showed considerable performance improvement in power output and in thermal efficiency, as well as substantial reduction in BSFC, HC, and CO emissions than that of a conventional carbureted engine. The results of this work can contribute to improve the air pollution in the urban area.

In this paper the experimental investigations relating to the performance and emission characteristics of a single cylinder spark ignition engine operating on a newly designed gasoline fuel injection system is described. This gasoline fuel injection system was operated under port injection configuration by controlling the duration of injection with PC based control system, which uses the information corresponding to engine speed and throttle positions. A comparison between the manually controlled version had indicated that the overall performance of the PC based fuel injection system is better than that of the manually controlled system fuel injection system.

A mathematical model for the gas exchange process and to estimate the pressure, temperature, velocity and mass flow rate at selected points in the exhaust and intake systems of a 4 stroke, single cylinder spark ignition engine is described. In order to evaluate the model, the computed data of gas pressure in intake system was compared with the experimental data while for the exhaust, the comparison include gas pressure and velocity. A satisfactory correlation was observed between the computed and test data.

This paper deals with the development and evaluation of a mathematical model for a 4-stroke, single-cylinder, spark ignition engine. This paper has two parts. The first part describes the development of the mathematical model and the computer program. The assumptions that were made in the model are also described. The instruments that were developed for the evaluation of the model are included in the second part, which also contains the evaluation of the results obtained from the model. The simulation results are found to agree well with the experimental data.

A Comprehensive computer simulation model was developed for a single cylinder spark ignition engine to simulate the Compression, Combustion, Expansion, Exhaust and Intake processes including the heat losses through the cylinder walls. The gas exchange processes were simulated with the help of a finite difference scheme and a separate boundary condition was developed for the throttle action on a conventional carburetor. The model after validating with the experimental data was used to arrive at the optimum duration and lift of the intake valve corresponding to different throttle positions of the equivalent conventional engine. These optimum values were used in the design of a 3 dimensional cam. Based on this design a new variable valve timing engine (VVT) has been designed and developed. Comparison between the computed and experimental data for the VVT engine was observed to be satisfactory.