The Chevrolet Corvair’s Turbo-Air 6 engine (1960–1969) was a rear-mounted, air-cooled flat-six (horizontally opposed or “boxer”) engine

This was highly unusual for American cars of the era, which typically used front-mounted, water-cooled V8s or inline engines. It shared some conceptual similarities with Volkswagen and Porsche air-cooled designs but was a unique GM creation. 

Key Unique Features

• Air-cooled flat-six layout: Cylinders arranged horizontally in two opposing banks of three. No radiator or liquid cooling system—instead, it used a large centrifugal blower fan (driven by a V-belt from the crankshaft) to force air over finned cast-iron cylinder barrels and aluminum heads. Shrouds directed the airflow, with thermostatically controlled doors for temperature regulation. 

• Lightweight materials: Two-piece aluminum crankcase, aluminum cylinder heads (with integral intake manifolds—one per side), and separate finned cast-iron cylinder barrels. The crankshaft (early versions) had no counterweights for weight savings. 

• Rear-engine placement: Mounted behind the rear axle in the trunk area, contributing to a rear weight bias (which led to handling quirks addressed in later models).

• Other details: Gear-driven camshaft below the crankshaft, hydraulic lifters with external pushrod tubes, two single-barrel Rochester carburetors (one per bank), and displacements from ~140–164 cu in (2.3–2.7L) producing 80–110+ hp (naturally aspirated; turbo versions went higher).

Firing order: 1-4-5-2-3-6. 

Here are some helpful visuals showing the engine’s layout and cutaways: