Supercharger Oil Cooling System The report provides a comprehensive overview of the design, implementation, and testing of a supercharger oil cooling system tailored for Paxton SN60 and VS57 superchargers. These superchargers rely on a planetary ball drive mechanism, which is highly effective but prone to significant heat generation. Overheating risks are particularly acute during high-performance scenarios, such as sustained operation with boost levels exceeding 6 psi. This project was initiated to address these challenges, protect the hardware, and extend its service life by maintaining optimal oil temperatures. Background and Motivation Paxton SN60 and VS57 superchargers are valued for their performance but require careful thermal management to ensure longevity. Excessive heat, primarily from the ball drive and impeller, can degrade lubricating fluid, reduce efficiency, and cause mechanical wear. Existing aftermarket cooling solutions provided incomplete and inconsistent data on performance, often failing to address critical aspects such as fluid temperature targets or…

Diagnosing and resolving a tappet failure in a modified engine can be a complex endeavor, especially when the problem leads to a complete redesign of the valvetrain. This project began with an abnormal exhaust gas temperature (EGT) reading in cylinder No. 2, which consistently displayed temperatures around 300°F, far below the 700–900°F range of the other cylinders. Adjustments to fuel and timing provided minimal improvement, prompting further investigation. A leak-down test revealed the intake valve was not sealing properly, leading to the discovery of tappet interference and, ultimately, cracked tappets. OEM Continental tappets were unsuitable due to their smaller face diameter, which was incompatible with the modified camshaft profile.  Hudson tappets, with their larger diameter head, were installed, but shortened to work with Isky springs and a set of off-the-shelf valves.  The shortened Hudson tappets removed critical features, such as flats required for adjustment, and suffered from mechanical stress that…

Overview The Crankcase Evacuation System (CES) was developed to address engine blow-by gases, which can cause crankcase overpressure, oil leaks, and decreased engine efficiency. Traditional systems, such as the Draft Tube and Positive Crankcase Ventilation (PCV) systems, have limitations for high-performance engines. This project explores mechanical and electrical CES configurations to maintain a crankcase vacuum of 5 in·Hg at 10 CFM flow, ensuring optimal engine performance and environmental compliance. Traditional Systems and Limitations Draft Tube System: Uses Bernoulli’s principle to create a low-pressure zone for ventilation but is ineffective at low speeds. Provides negligible crankcase vacuum at typical operating conditions. PCV System: Relies on intake manifold vacuum to pull air through the crankcase, directing blow-by gases into the combustion process. High-performance engines face challenges with PCV systems due to contamination and air-fuel ratio disruption, necessitating additional enhancements like oil separators. CES Development and Testing The project consisted of six test…

Part 1: The Dynamics of Throttle Plate Position and Flow Area Understanding the relationship between throttle plate position and airflow is critical for optimizing engine performance. This connection directly impacts how efficiently an engine can transition from idle to full throttle. In this post, we’ll break down this relationship and its significance. Figure 1 shows how the flow area changes with throttle plate position. The red curve represents the actual airflow through the throttle body, while the black line shows the output of a linear potentiometer directly linked to the throttle shaft. Key observations include: Nonlinearity in Low Throttle Positions:** Between 0° and 60°, the red curve illustrates a steep rise in flow area that does not match the linear output of the black line. This mismatch creates a “rich” condition—where more fuel is supplied than necessary relative to airflow. Alignment in Higher Throttle Positions:** From 60° to 90°, the…

Part 2: Linear vs. Nonlinear Throttle Position Sensor Response Throttle control becomes a challenge when the engine demands rapid response, and the linear TPS struggles to keep up. This post examines why linear potentiometers fall short and how adjusting their response curve can provide a solution. Figure 2 highlights the mismatch between a linear TPS response and actual airflow requirements. The black line represents a direct 1:1 coupling between the TPS and the throttle shaft. The green curve, however, shows the desired convex response that aligns with engine needs. Key insights include: Mismatch in Early Throttle Movement:** The green curve rises more steeply at low throttle positions, reflecting the higher enrichment needs during acceleration. Ideal Response Curve:** The convex green line ensures sufficient enrichment at every throttle position, particularly in the critical 0°-60° range. Engines using a linear TPS often struggle to deliver sufficient enrichment during rapid acceleration. This is…

Part 3: Mechanical and Electronic Solutions for Optimal Throttle Response To solve the enrichment problem, engineers can turn to either mechanical linkages or electronic modifications. This post explores both approaches and their advantages. Figure 3 shows how varying linkage ratios can create the desired convex response. By using levers, bellcranks, or idler shafts, engineers can: Accelerate TPS movement by linking a longer input arm to a shorter output arm generates a faster TPS response at low throttle positions. Align full throttle positions so that the TPS and throttle plate each reachs 100% open simultaneously, ensuring proper calibration. Instead of mechanical adjustments, electronic modifications can reshape the TPS output signal before it reaches the engine control module (ECM). Advantages include: Flexibility: Easily adjustable response curves to match specific engine requirements. Adaptability: Ideal for modern engines with more sophisticated algorithms. Whether using mechanical or electronic solutions, these adjustments offer better throttle response…