Fig 4 Performance Results at 2000 RPM Showing Effect of LHR Engine Operation

had no effect on indicated thermal efficiency (ITE) while slightly increasing the low load smoke and full load particulate emissions. The insulated engine at baseline conditions had significantly lower ITE, with higher smoke and particulate emissions (especially at full load) compared to the baseline uninsulated engine. Increasing the coolant temperature of the ceramic insulated engine slightly reduced the ITE at full load, and increased the lowest load particulate emissions compared to the baseline insulated engine. Advancing the fuel injection timing 2 degrees for the "hot ceramic" engine had no measurable effect on ITE 'while slightly reducing the smoke and particulate emissions. Retarding the fuel injection timing by 6 degrees reduced the ITE and significantly increased smoke and particulate emissions. The most significant result of these tests is that the addition of ceramic insulation and subsequent reduction of heat transfer to the coolant did not improve engine performance relative to the baseline metal engine.

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