AN UPDATE ON ACHATES' REVOLUTIONARY ENGINE - AUTOLINE AFTER HOURS 264

EV Channels Review

This episode of Autoline After Hours features David Johnson of Achates Power discussing their revolutionary opposed-piston, two-stroke engine technology. The core innovation lies in eliminating the cylinder head and valve train, utilizing ports in the cylinder wall for intake and exhaust, and employing direct fuel injection. Achates claims significant advantages, including a 30% smaller combustion chamber surface area to volume ratio, leading to reduced heat loss and improved efficiency. They demonstrated a 2.25L Achates engine replacing a 5.6L V8 in a Nissan Titan, achieving nearly double the fuel economy (an 86% increase in MPG) while meeting Tier 3 emissions standards. The engine design allows for sculpted piston crowns that create a "football-shaped" combustion chamber, promoting efficient swirl and tumble for a fast, clean burn. Achates addresses traditional two-stroke drawbacks like oil mixing and emissions by using sump lubrication and advanced combustion control. They highlight potential cost savings of 5-10% on the base engine compared to conventional diesels, with further reductions in after-treatment systems due to lower inherent emissions. While durability testing is ongoing, the company is actively developing engines for various applications, from 50hp to 3.8MW, with potential for passenger vehicles around 2020-2025.