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Experimental data was obtained from a Rover K4 optical access engine and analyzed with a combustion analysis package. Cyclic NO values were calculated by mass averaging the measurements obtained by a fast NO analyzer. While the mass averaged results were used as the basis of comparison for the model, results indicate that mass averaging a fast NO signal is not nearly as critical as mass averaging a fast FID signal. A computer simulation (ISIS - Integrated Spark Ignition engine Simulation) was used to model the NO formation on a cyclic basis by means of the extended Zeldovich equations. The model achieves its cyclic variability through the input of experimentally derived burn rates and a completeness of combustion parameter, which is based on the Rassweiler and Withrow method of calculating mass fraction burned and is derived from the pressure-crank angle record of the engine.

The Vauxhall 14-40 was introduced in 1922 and is a good example of contemporary best practice. In its first 20 years Vauxhall had established a strong reputation for sporting performance, and the 14-40 was their first vehicle aimed at the middle classes. The 14-40 has extensive use of aluminum alloy castings, a unitary engine clutch and gear box with a torque tube coupling to the back axle, half elliptic front springs with a beam axle and cantilevered rear leaf springs. The engine was heavily influenced by Ricardo, so as to have low friction levels and a good combustion performance. The engine design will be reviewed in the context of the fuel available in the 1920s. This paper reviews the vehicle technology in the context of its contemporaries, and makes use of contemporary engine performance data for tuning a simple engine model, the results of which are to be used in a vehicle simulation.

This paper investigates a technique of calculating the completeness of combustion on a cycle-by-cycle basis. The technique introduces the normalized pressure rise due to combustion parameter (Ψ) to describe the completeness of combustion. This parameter is based on the Rassweiler and Withrow method of calculating mass fraction burned and is derived from the pressure-crank angle record of the engine. Experimental data were obtained from a Rover K4 optical access engine and analyzed with a combustion analysis package. A computer simulation was then used to model the data on a cyclic basis, both with and without the completeness of combustion parameter. The inclusion of completeness of combustion improved the simulation's ability to model the experimental data both in a statistical sense (COV of IMEP) and on a cycle-by-cycle basis.

This work examines the possibility of detecting misfires via measurements of the angular acceleration of the engine block. Measurements were taken on a production 4-cylinder engine which was modeled as a single degree of freedom torsional oscillator. The torque waveform was estimated and compared to the torque calculated via cylinder pressure measurements. Further analysis was conducted in the frequency domain. Results indicate that metrics based on low frequency information were most reliable, but this is impractical for vehicular applications. The accuracy of high frequency metrics was degraded due to the limitations of the model and the non-rigid behavior of the block at high engine speeds.