Willys Lightning engine

The Lightning engine is a Willys straight-6 produced in the 1940s and 1950s. The flathead engine featured four main bearings and solid valve lifters.
The engines were used in the Willys Jeep Station Wagon, other Jeep-based vehicles, and Willys sedans.

L148

The L148 version displaced and was rated at. This was the smallest displacement six-cylinder engine when introduced in 1947 in the Willys Station Wagon. The bore was and its short stoke enabled the engine to achieve high revolutions given its
flathead design.
Applications:

1947-1950 Willys Jeep Station Wagon
1948 Willys-Overland Jeepster

L161

The L161 version displaced and was rated at. Introduced in April 1950, the engine featured a higher compression ratio of 6.9 to 1, and a larger bore.
Applications:

1950-1951 Willys Jeep Station Wagon
1950 Willys-Overland Jeepster
1952-1955 Willys Aero-Lark
1953-1955 Willys Aero-Falcon

Replacement

The F-head Hurricane engine was introduced in 1950, a significant upgrade to the Lightning. The valve configuration was changed for better power and efficiency. In 1954, the 6-226 "Super" Hurricane was introduced.