Are you craving a collector car with an air-cooled, flat-six engine, but feel like the Porsche 911 market is overheated? There is an excellent and affordable alternative: the “Turbo Air 6” in Chevrolet’s Corvair.
The 1960 Chevrolet Corvair made its debut powered by the rear-mounted 140-cu.in. Turbo Air 6.Photo by David LaChance
The Turbo Air 6’s design was influenced by Volkswagen’s flat four but inspired by aircooled, aircraft and tank engines that Chevrolet’s Chief Engineer Ed Cole was familiar with. The foundation for the Turbo Air 6 was a two-piece cast-aluminum crankcase with a crankshaft that rode in four main bearings. The camshaft was located below the crankshaft and driven by gears off of the crank. Hydraulic valve lifters were standard issue and activated hollow pushrods concealed inside steel tubes on the outside of the engine. The rocker arms were lightweight stamped steel like those used on Chevrolet small-block and big-block engines. Each cylinder was contained in a separate, finned, cast-iron barrel and the opposed banks of three were each capped with a cast-aluminum, overhead-valve head. The heads had cast-in cooling fins as well as integral intake manifolds and were fastened with studs through the cylinder barrels. A pair of Rochester one-barrel carburetors — one for each bank of cylinders — fed fuel and air to the engine.
By ’62, the year of this engine powering a station wagon, the Turbo Air 6 had grown to 145-cu.in.Photo by Richard Lentinello
A forced-air system cooled the Turbo Air 6, at the heart of which was an 11-inch diameter centrifugal engine blower mounted horizontally on the top center of the engine. With 24 vanes and driven by a V-belt off the crankshaft, via an idler, the blower could produce 1,850-cfm of air flow at 4,000 engine rpm. Sheetmetal shrouds encased the engine to keep the air flowing over the cooling fins and thermostatically controlled doors on the lower portions of the shroud allowed hot air to escape. Early engines with steel blowers had a tendency to throw V belts so, in ’64, Chevrolet replaced the steel unit with a lightweight magnesium blower. Something that all Corvair engines have in common with Porsche sixes? Yep, oil leaks — from the pushrod tubes and crankshaft seal are pretty common.