It took a century for automotive engines to mature from cantankerous contraptions to the smooth, reliable machinery that currently enables our mobility. The following honor roll celebrates the 10 best - those engines that motored far beyond the call of duty to advance the internal-combustion cause.
Ford Motor Co. Model T Inline-4 (1909) After eight lackluster designs, Henry Ford finally hit paydirt with his 1909 Model T. Its 20-hp 2.9L 4-cyl. engine was engineered for low-cost manufacturing and shade-tree servicing. Contrary to convention, the T's powerplant combined four cylinders and the upper half of its crankcase in one casting. To save complication, internal parts were lubricated by gravity and splash; coolant was circulated by a thermosiphon effect.
Reducing the price as production volumes climbed - from an initial $850 to $260 in 1925 - spurred demand for more than 16 million Model Ts and fulfilled Henry's dream of a motorcar for the multitudes.
General Motors Corp. Cadillac V-8s (1915) Cadillac didn't invent the V-8 - but it was the first to sustain that engine configuration with volume production. The original 1915 "L-head" design yielded 70 hp from 5.1L and introduced thermostatic control of coolant circulation. The addition of a counterweighted two-plane crankshaft in 1924 further enhanced Cadillac's reputation for smooth, quiet running.
In 1949, a horsepower war was triggered by Cadillac's first overhead-valve V-8, which delivered 160 hp from 5.4L. That design was tough enough for respectable finishes at the 24 Hours of LeMans and smooth enough to send luxury-class competitors back to the drawing boards. Cadillac's Northstar DOHC 32-valve updates for 1993 and 2000 advanced Cadillac's V-8 rep as a standard-setter for V-8 smoothness, quietness and efficiency.
Ford L-Head V-8 (1932) In the teeth of the Great Depression, Henry Ford rocked the motoring world with speed for the masses: the industry's first affordable V-8. Like his Model T engine, this 1932 65-hp, 3.6L design incorporated the best available materials and notable engineering advances: a forged-steel crankshaft, aluminum pistons, babbited bearings, a single-piece cylinder block and rubber mounting.
Subsequent model years brought aluminum cylinder heads, more efficient carburetion and more power. Both John Dillinger and Clyde Barrow took a break from crime to write letters of appreciation. The Ford flat-head V-8 was every hot rodder's engine of choice for two decades.
Volkswagen AG Flat-4 (1945) Envious of America's Henry Ford-inspired mobility, Adolf Hitler commissioned the renowned Ferdinand Porsche to engineer a "people's car," or Volkswagen. Challenged by ambitious cost and performance targets, Porsche selected an air-cooled, horizontally opposed 4-cyl. yielding 24-hp from its 1L, and positioned the engine at the rear to optimize packaging efficiency. That, in turn, necessitated light-weight materials, including a magnesium crankcase and aluminum cylinder heads, to achieve balance.
World War II delayed Beetle production until 1945, but when Germany regained control of the Wolfsburg plant in 1948, the country had the perfect car for austere times. Today, Type One Beetle production continues in Mexico with total volume at 21 million units and counting.
General Motors Corp. Chevrolet Small Block V-8 (1955) Chevrolet repeated Ford's power-to-the-people initiative in 1955 with one of the most efficient and durable V-8 designs ever to power an automobile. An oversquare bore-to-stroke ratio and a short-skirt, thin-wall block saved weight and bulk. Efficient porting aided volumetric efficiency. An inexpensive yet durable valvetrain used stamped rocker arms pivoting on ball-shaped pedestals. Starting with 162 hp (gross) from 4.3L, subsequent versions grew to 6.5L and reached 330 hp (net) in 1996 Corvette trim.
To date millions of small-block V-8s have been produced to power a multitude of cars and light trucks sold by every GM division except Saturn. Two years from now, the baton finally passes to Gen III successors when the original small block leaves production after 48 years of faithful service.
General Motors Corp. Buick V-6 (1962) Buick's 90-degree V-6 is the poster child of a bad idea turned good through fastidious refinement. In 1962, this engine was rudely chopped from a V-8 to supplant a troublesome all-aluminum V-6. Unequal firing intervals caused so much idle shake that Buick soon dumped its V-6 and tooling was sold to Kaiser-Jeep. When the first energy crisis prompted a rethink, Buick's V-6 returned home. A continuous refinement program began with a split-throw, even-firing crankshaft in 1978 and culminated with a top-to-bottom overhaul for 1995.
In spite of GM's hidebound adherence to a pushrod valvetrain and cast-iron construction, Series II 3800s still excel in packaging efficiency, fuel economy, smoothness and reliability.
Porsche AG Flat-6 (1964) Born in 1964, Porsche's original flat 6-cyl. - a design commonly known as "boxer" because of its opposed pistons - thrust the founding father's Beetle engine concepts into the competitive crucible of sports and racing machinery. It was an auspicious leap from the 911's 130-hp, 2L trim at the 1963 Frankfurt Auto Show to the engine's 190-hp competition debut at a Paris 1,000-km (625-mile) race only a year later. The addition of turbocharging for both street and track pumped power curves smartly upward in the 1970s. Lessons learned from four LeMans 24-hour victories helped boost street output over the 400-hp mark by 1997.
A transition to liquid cooling initiated by the 1997 Boxster was completed by the second-generation 911 Carrera for 1999. A wealth of advanced features, including variable valve timing and intake tracts, four-valve combustion chambers, etched-silicon cylinder bores and direct ignition should stand this engine design in good stead well into the new century.
BMW AG Inline-6s (1968) The M in BMW's name stands for Motoren (Motor), indicative of the importance engines play in this company's heritage. Before BMW began light-car construction in 1927, it earned its reputation as a worthy motorcycle, aircraft, and truck engine maker. Rebuilding after WWII tested the firm's mettle, but by 1968 BMW was ready to challenge arch-rival Mercedes-Benz's S-Class sedan. To create an appropriate engine for that task, BMW simply stretched its successful SOHC 2L 4-cyl. into a 2.5L 6-cyl. In the 1980s, when competitors turned toward more compact V-6 engines, BMW bucked the trend by continuing to nurture its inline sixes through four generations. Each new generation has been lighter, smaller, more powerful and sweeter-running than its predecessors.
Honda Motor Co. Ltd. CVCC Inline-4 (1975) In 1975, the auto industry scrambled to meet 1980 emission standards accelerated by the late Sen. Edmund Muskie's "feet-to-the-fire" initiative. Fortunately, GM had just spent five years perfecting the industry's first catalytic converters. But at Honda, an eight-man team needed only one year to meet Clean Air Act requirements with an ingenious Compound Vortex Controlled Combustion (CVCC) 4-cyl. engine. Instead of using a catalytic converter to cleanse the exhaust stream, a three-valve combustion chamber minimized pollution formation inside the engine. CVCC's lineal descendant is a 2.3L VTEC (Variable valve Timing and lift Electronic Control) 4-cyl. engine that recently helped the Accord earn the first ever Super Ultra Low Emission Vehicle (SULEV) certification in California.
Toyota Motor Corp. Lexus V-8 (1990) To close out the millennium's final decade with a bang, Toyota served notice it was ready for all comers by introducing the 1990 Lexus 400 luxury sedan. Under the hood, a 4L V-8 embodied every notable technical advance in the book, including aluminum block-and-head construction, dual overhead camshafts and four-valve combustion chambers; champagne glasses piled high on the LS 400's hood never dripped as this engine accelerated with electric-motor smoothness to a lofty redline. BMW, Cadillac, Jaguar, and Mercedes-Benz returned to their laboratories.
To seal the bargain, Toyota recalibrated its illustrious V-8 to wage battle in four diverse market segments - sporting coupes and sedans, luxury SUVs and full-sized-pickups. In the competitive world of engine design, the best never rest.