A flat-16 is an internal combustion engine in flat

Flat engine

A flat engine is an internal combustion engine with multiple pistons that move in a horizontal plane. Typically, the layout has cylinders arranged in two banks on either side of a single crankshaft and is sometimes known as the boxer, or horizontally opposed engine. The concept was patented in 1896...

 configuration, having 16 cylinders.

Few examples are known. The British engine manufacturing company Coventry Climax

Coventry Climax

Coventry Climax was a British forklift truck, fire pump, and speciality engine manufacturer.-History:The company was started in 1903 as Lee Stroyer, but two years later, following the departure of Stroyer, it was relocated to Paynes Lane, Coventry, and renamed to Coventry-Simplex by H...

 developed a racing flat-16 unit for the 1.5 litre Formula One

Formula One

Formula One, also known as Formula 1 or F1 and referred to officially as the FIA Formula One World Championship, is the highest class of single seater auto racing sanctioned by the Fédération Internationale de l'Automobile . The "formula" designation in the name refers to a set of rules with which...

 between the 1963

1963 Formula One season

The 1963 Formula One season was the 14th season of FIA Formula One motor racing. It featured the 14th FIA World Championship of Drivers, the sixth International Cup for F1 Manufacturers and numerous non-championship Formula One races...

 to 1965 Formula One season

1965 Formula One season

The 1965 Formula One season, which was the 16th season of FIA Formula One racing, featured the 16th World Championship of Drivers and the 8th International Cup for F1 Manufacturers. The two titles were contested concurrently over a ten round series which commenced on January 1 and ended on October 24...

s,the FWMW, but, although the Brabham and Lotus

Team Lotus

Team Lotus was the motorsport sister company of English sports car manufacturer Lotus Cars. The team ran cars in many motorsport series including Formula One, Formula Two, Formula Ford, Formula Junior, IndyCar and sports car racing...

 teams designed cars for the engine, given the success of the Climax FWMV V8 unit it was never raced. Porsche ran some tests with a dual-spark flat-16 Can-Am version of the Porsche 917

Porsche 917

The Porsche 917 is a racecar that gave Porsche its first overall wins at the 24 Hours of Le Mans in 1970 and 1971. Powered by the Type 912 flat-12 engine of 4.5, 4.9, or 5 litres, the 917/30 variant was capable of a 0- time of 2.3 seconds, 0– in 5.3 seconds, and a top speed of over .There are 6...

, but it too was never raced, as turbocharging the flat -12 produced the required increased power.