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The following section contains the results of our engine tests. The first set of data was collected from the original engine. More data was collected on the exhaust emissions. An OTC-3729 exhaust gas analyzer was used to collect the emission data while the power data was being acquired. The emissions, horsepower, and torque data for the baseline engine are represented in the following charts:
Chart 1: Baseline Frictional Power Loss
Chart 2: Baseline Power, Torque and Fuel Consumption
Chart 3: Baseline Emissions Data
The initial stage of baseline testing was to run the dynamometer without combustion to determine internal engine friction. The internal engine friction accounts for the amount of power required just to rotate the engine. Chart 1 shows the horsepower loss due to internal friction over a range of engine speeds. The power curves shown in Chart 2 indicate the power output of the engine. This number is the actual power minus the friction power. Frictional losses detract from the performance of the engine therefore the goal is to decrease the amount of friction as much as possible. The first experimental system tested was the
lubrication system. This needed to be tested first to ensure that the engine
would not seize during operation. Chart 4 below shows the experimental
internal friction power losses after the installation of the test system.
The curve corresponds closely to the baseline system although the friction
is slightly higher in the new system. Chart 4: Lubrication System Frictional Power Losses
The next set of testing was done on the full system including the fuel injection. Chart 5 shows the torque and power curves obtained from testing. From the collected data it was found that the power was increased by roughly 2.5 horsepower when compared to the baseline engine as indicated in Chart 6. However, it was determined that the system was not running consistently. Intermittent ignition possibly due to fouling of the sparkplugs resulted in low power levels at some engine speeds or a lack of data. This problem was also encountered during stock system testing. The original engine electrical system in its present form is unreliable and should be replaced. Due to time and money constraints this could not be done. The emissions data that would be crucial to the injection system tuning was also unobtainable. One reason for this was linked to the intermittent ignition, which filled the exhaust with unburned fuel and produced a poor exhaust stream. This was confirmed qualitatively by looking at the exhaust, shown in pictures below. Instead of burning a gray color the exhaust was blue, which confirms our suspicions of improper combustion at some engine speeds. Also, the OTC-3729 emissions analyzer was not reading data. The baseline test was so dirty that the filter was quickly clogged and restricted flow to the analyzer, rendering the analyzer inoperable. A replacement filter was unable to be obtained in time to get data prepared for this report.
Chart 5: Power and Torque Curves with Systems
Chart 6: Power and Torque Output Comparison Shown below is the exhaust before our oil and fuel injection systems were added.
It seems clear that the exhaust was cleaned up quite significantly. However it's impossible to say how much of an improvement was made because we have no emissions data from the second picture. |
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