The next-generation Northstar DOHC 4.6L V8 engine with four-cam continuously variable valve timing for Cadillac

摘要

A new-generation Northstar DOHC V8 engine has been developed for a new family of rear-wheel-drive (RWD) Cadillac vehicles. The new longitudinal engine architecture includes strategically selected technologies to enable a higher level of performance and refinement. These technologies include four-cam continuously variable valve timing, low restriction intake and exhaust manifolds and cylinder head ports, a steel crankshaft, electronic throttle control, and close-coupled catalysts. Additional design features beyond those required for RWD include optimized block ribbing, improved coolant flow, and a newly developed lubrication and ventilation system for high-speed operation and high lateral acceleration. This new design results in improved performance over the entire operating range, lower emissions, improved fuel economy, improved operating refinement, and reduced noise/vibration/harshness (NVH). Simultaneous engineering and extensive use of math-based 3D modelling and analysis were the cornerstones of the project from inception. This reduced development time and the amount of required development hardware while ensuring the highest reliability for the new engine. Manufacturing implementation required the maximum possible commonality with the transversely mounted front-wheel-drive (FWD) Northstar engine.