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In a year-long endeavor fueled by passion and determination, Lingenfelter Performance Engineering (LPE) embarked on a challenging mission to bring the legendary 427 badge back to the Corvette. The project encountered numerous hurdles, yet the LPE team persevered with a singular goal in mind. This new engine package will be offered through the Lingenfelter Eliminator program as a Spec S engine combination.
The new Lingenfelter Eliminator Spec S 427 cubic inch LT2 was developed entirely in-house. The entire team at LPE took their decades of engine building and development experience to create solutions to obstacles that are unique to the C8 Corvette platform. The result is a naturally aspirated 7.0-liter LT2 that has good street manners with enough power to make any drive exciting.
The task at hand was not without its complexities, chiefly due to the mid-engine layout of the C8 and its new for the platform dual-clutch transmission (DCT). LPE COO/VP Operations, Mark Rapson, informed us this project demanded a new approach to engine program development for the Lingenfelter team, beginning with the Corvette’s new LT2 engine as the foundation. The LT2, tailored specifically for the Corvette platform, boasts unique design elements internally and externally to accommodate its mid-engine configuration and performance demands.
The Eliminator Spec S 427 LT is filled with high-quality components from Callies and MAHLE.
According to Rapson, one of the primary challenges arose from the LT2’s oiling system and flush-mount oil pan, specifically engineered by GM to make the LT2 and the C8 Corvette a truly track capable package. The oiling system features an all-new scavenging and scraper design that is integrated into the oil pan. Retaining this system was one of the key goals of the LPE 427 engine program.
To reach the desired cubic inch size of 427 LPE worked with Callies to develop a 4.00-inch stroke crankshaft that works with the LT2's flat oil pan and oiling system.
To achieve the desired 7.0-liter displacement, modifications to both bore and stroke were necessary. However, considerations extended beyond the engine itself, encompassing critical components such as the vehicle management system and transmission control module. Factors such as shift RPM limitations, idle smoothness, torque delivery, and fuel octane requirements were analyzed to ensure optimal performance and drivability.
The chosen bore and stroke configuration, featuring a long-stroke setup, aimed for optimum torque within the engine’s operational range. Rapson explained that initial plans for a 4.00-inch stroke crankshaft and a 4.125-inch bore closely mirrored the classic Z06 (LS7) 7.0-liter configuration, but the feasibility of this configuration playing nice with the LT2 oil pan and oiling system remained uncertain.
The engineers at LPE created CAD models of the LT2 to make the necessary modifications for the 4.00-inch stroke crankshaft to rotate freely within the engine block and oil pan.
The development process kicked off with engineers gathering CAD data on the LT2 while the engine team initiated mock-ups using a conventional 4.00-inch stroke rotating assembly. According to Rapson, it soon became apparent that a new crankshaft design was necessary to accommodate the desired stroke length. Collaboration with industry leader Callies ensued, resulting in the creation of a unique eight counterweight crankshaft designed to maintain balance while fitting within the constraints of the LT2 oiling system.
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Completing the rotating assembly is Callies 6.125-inch long H-beam connecting rods paired with MAHLE 4.125-inch bore 2618 Power Pack pistons. Precision machining of the block, including CNC blueprinting and installation of larger sleeves and lifter bushings, are essential parts of the LPE 427 engine program to accommodate the increased piston size and longer stroke.
Rapson and the LPE team then turned their attention to the camshaft and cylinder heads, critical components influencing both power delivery and drivability. A proprietary camshaft was developed, tailored to the LPE 7.0-liter specifications to ensure smooth airflow and torque management. The utilization of stock LT2 heads, coupled with in-house CNC porting and expert assembly, further improved performance and efficiency.
After many months of development and testing, the culmination arrived in late February 2024, with the assembly of the LPE LT2 427 engine. On March 4, 2024, the engine roared to life on the dyno, exceeding expectations with an impressive output of 704 horsepower and 600 lb-ft of torque on 91 octane fuel, boasting an impressively flat torque curve.
The LPE test car that has competed in autocross and road racing will receive the first Eliminator Spec S 427 LT2 and put it through real-world testing.
While we are sure there are customers ready to get their LPE 427 LT2 ordered, Rapson and his team are going to install the engine in LPE’s 2020 C8 test mule to put the new engine through real world testing on the streets and the track. Stay tuned as LSX Magazine brings you updates on this exciting engine program from Lingenfelter Performance Engineering.
