Flat-12

From WOI Encyclopedia Italia

A flat-12 is an internal combustion engine in flat configuration, having 12 cylinders.

The flat-12 is larger than a V12 and has no advantage in terms of vibrations. Thus the design is rarely used on production cars.

Most of the flat-12 engines are not true horizontally opposed engines (boxer) but rather 180° V engines. The real boxer has one crank pin per piston while in the 180° V engine two pistons share the same crank pin. With twelve cylinders both layouts are perfectly balanced.

It was used in Formula One and Endurance racing, the flat engine concept had the advantage of a low center of gravity. When wing-cars requiring air-flow venturies came along in the late 1970s, the wide flat-layout obstructed the airflow and became obsolete.

In 1964-65, at the end of the 1.5 litre F1 era, Ferrari introduced a flat-12 on the Ferrari 1512, but a more classical V12 was chosen for the new 3 litre F1.

The Porsche 917 endurance racing car (introduced in 1969, for the Sport category) was powered by an air-cooled flat-12. This engine was an evolution of the Porsche flat-8 boxer engine and in fact used identical cylinders to those found on the 908 but it did differ in that it used a V12 type crankshaft.

The domination of the Porsche 917 over the V12-powered Ferrari 512 probably influenced Ferrari, for they returned to the flat-12 in 3 litre water-cooled form for its prototypes and Formula One cars.

The Ferrari flat-12 design was successful and influential especially on Italian manufacturers, Alfa-Romeo was also successful in endurance with a flat-12 while the Tecno Formula One flat-12 was a failure.

A 4.4-5.0 L 180° V12 was later introduced by Ferrari in some of its production models, including the Berlinetta Boxer and Testarossa.

Articles relating to Automobile configurations
Car body style and classification	2 plus 2 | Antique car | Cabrio coach | Cabriolet | City car | Classic car | Compact car | Compact performance car | Compact SUV | Convertible | Coupé | Coupé convertible | Coupe Utility | Crossover SUV | Custom car | Drophead coupe | Fastback | Full-size car | Grand tourer | Hardtop | Hatchback | Hot hatch | Hot rod | Large family car | Leisure activity vehicle | Liftback | Limousine | Luxury car | Microcar | Mid-size car | Mini SUV | Minivan | Multi-purpose vehicle | Muscle car | Notchback | Personal luxury car | Pickup truck | Retractable hardtop | Roadster | Sedan | Saloon | Small family car | Sport compact | Sports car | Sport utility vehicle | Spyder | Station wagon | Estate car | Supermini | Targa top | Taxicab | Touring car | Town car | T-top | Ute | Van | Voiturette
Specialised vehicles	Gyrocar | Flying car. Amphibious vehicle
Fuel technologies	Internal combustion engine | Electric vehicle | Neighborhood electric vehicle | Hybrid vehicle | Battery electric vehicle | Hydrogen vehicle | Fuel cell | Plug-in hybrid electric vehicle | Steam car | Alternative fuel cars | Biodiesel | Gasohol | Ethanol | LPG (Propane) | Homogeneous Charge Compression Ignition | Liquid Nitrogen | Gasoline Direct Injection
Driven wheels	Four-wheel drive | Front-wheel drive | Rear-wheel drive | All-wheel drive | Two-wheel drive
Engine positioning	Front engine | Rear engine | Mid engine
Layout	FF layout | FR layout | MR layout | MF layout | RR layout
Engine configuration	Internal combustion engine | Straight-6 | V engine | Wankel engine | Reciprocating engine | Inline engine | Flat engine | Flathead engine | Diesel engine | Two-stroke cycle | Four-stroke cycle | Pushrod engine | Straight engine | H engine | Turbodiesel | Hybrid vehicle | Rechargeable energy storage system | Electric vehicle | Hydrogen vehicle

Body	Framework	A-pillar | Bumper | Cabrio coach | Chassis | Crumple zone | Body-on-frame | Dagmar bumpers | Fender | Fender skirts | Grille | Hood | Hood scoop | Monocoque construction | Pontoon fenders | Quarter panel | Shaker scoop | Spoiler | Subframe | Tonneau
Doors	Butterfly doors | Gull-wing door | Scissor doors | Suicide door
Glass	Sunroof | Greenhouse | Windshield
Other	Antenna ball | Hood ornament | Japan Black paint | Nerf bar | Truck accessory | Bumper sticker
Exterior Equipment	Lighting	Daytime running lamp | Headlamp | Headlight styling | Hidden headlamps | Retroreflector | Sealed beam | Trafficators | High intensity discharge
	Other	British car number plates | Distance sensor | US and Canadian license plates | Vanity plate | Vehicle registration plate | Windscreen wiper | Windshield washer fluid
Car engine	Air/Fuel	Air filter | Automatic Performance Control | Blowoff valve | Boost | Boost controller | Butterfly valve | Carburetor | Charge cooler | Centrifugal type supercharger | Cold air intake | Engine management system | Engine Control Unit | Forced induction | Front mounted intercooler | Fuel filter | Fuel injection | Fuel pump | Fuel tank | Gasoline direct injection | Indirect injection | Intake | Intercooler | Manifold | Manifold vacuum | Mass flow sensor | Naturally-aspirated engine | Ram-air intake | Scroll-type supercharger | Short ram air intake | Supercharger | Throttle body | Top mounted intercooler | Turbocharger | Turbocharged Direct Injection | Twin-turbo | Variable Length Intake Manifold | Variable geometry turbocharger. Warm air intake
	Exhaust	Catalytic converter | Emissions control devices | Exhaust pipe | Exhaust system | Glasspack | Muffler | Oxygen sensor
	Cooling	Aircooling | Antifreeze | Ethylene glycol | Radiator | Thermostat
	Ignition system	Starter | Car battery | Contact breaker | Distributor | Electrical ballast | Ignition coil | Lead-acid battery | Magneto | Spark-ignition | Spark plug
	Other	Balance shaft | Block heater | Crank. Cam | Camshaft | Connecting rod | Combustion chamber | Crank pin | Crankshaft | Crossflow cylinder head | Crossplane | Desmodromic valve | Engine knocking | Compression ratio | Crank sensor | Cylinder | Cylinder bank | Cylinder block | Cylinder head | Cylinder head porting | Dump valve,Engine balance | Oil filter | Firing order | Freeze plug | Gasket | Head gasket | Hypereutectic piston | Hydrolock | Lean burn | Main bearing | Motor oil | Multi-valve | Oil sludge | Overhead camshaft | Overhead valve | PCV valve | Piston | Piston ring | Pneumatic valve gear | Poppet valve | Power band | Redline | Reverse-flow cylinder head | Rocker arm | Seal | Sleeve valve | Starter ring gear | Synthetic oil | Tappet | Timing belt | Timing mark | Top dead centre | Underdrive pulleys | Valve float | Variable valve timing
Interior equipment	Instruments	Backup camera | Boost gauge | Buzzer | Car computer | Carputer | Check Engine light | Fuel gauge | Global Positioning System | Idiot light | Navigation system | Odometer | Speedometer | Tachometer | Trip computer
	Controls	Bowden cable | Cruise control | Electronic throttle control | Hand brake | Manettino dial | Steering wheel | Throttle | Gear stick
	Motor vehicle theft deterrence	Car alarm | ESITrack | Immobiliser | Klaxon | Vehicle tracking system | VIN etching
	Passenger safety & seating	Airbag | Armrest | Automatic seatbelt | Bench seat | Bucket seat | Child safety lock | Dicky seat | Passive safety | Rumble seat | Seat belt
	Other	Air conditioning | Ancillary power | Car audio | Car phone | Center console | Dashboard | Motorola connector | Power window | Rear-view mirror | TripSense
Powertrain	Wheels and Tires	All-terrain tyre | Bias-ply tire | Contact patch | Custom wheel | Drive wheel | Hubcap | Magnesium alloy wheel | Mud-terrain tyre | Paddle tires | Radial tire | Rostyle wheel | Run flat tires | Schrader valve | Slick tire | Spinner | Tire code | Tread | Treadwear rating | Whitewall tire | Wire wheels
	Transmission	Automatic transmission | Clutch | Continuously variable transmission | Differential | Driveshaft | Electrorheological clutch | Epicyclic gearing | Fluid coupling | Fully-automatic transmission | Gear stick | Gearbox | Hydramatic | Limited slip differential | Locking differential | Manual transmission | Roto Hydramatic | Saxomat | Semi-automatic transmission | Semi-automatic transmission | Super Turbine 300 | Tiptronic Torque converter | Transmission (mechanics) | Transmission Control Unit | Turbo-Hydramatic | Universal joint
	Steering	Ackermann steering geometry | Anti-lock braking system | Camber angle | Car handling | Caster angle | Oversteer | Power steering | Rack and pinion | Toe angle | Torque steering | Understeer
	Suspension	Axle | Beam axle | Coil spring | De Dion tube | Double wishbone | Electronic Stability Control | Hydragas | Hydrolastic | Hydropneumatic suspension | Independent suspension | Kingpin | Leaf spring | Live axle | MacPherson strut | Multi-link suspension | Panhard rod | Semi-trailing arm suspension | Shock absorber | Sway bar | Swing axle | Torsion beam suspension | Transaxle | Trailing arm | Unsprung weight | Watt's linkage | Wishbone suspension
	Brakes	Anti-lock braking system | Disc brake | Drum brake | Hand brake | Hydraulic brake | Inboard brake | Brake lining | Brake fade | Brake fluid | Hydraulic fluid | Brake bleeding | Engine braking | Electronic brakeforce distribution | Regenerative brake

Piston engine configurations
Straight	Single, 2, 3, 4, 5, 6, 8, 9, 10, 12, 14
V	2, 4, 5, 6, 8, 10, 12, 16, 20, 24
Flat	2, 4, 6, 8, 10, 12, 16, H
W	8, 9, 12, 16, 18
Other inline	H, VR, Opposed, U (Square), X
Other	Hemi, Radial, Rotary, Pistonless, Deltic, (Wankel)

Heat engines
Stroke cycles One • Two • Four • Six •
Engine types Gas turbine • Piston • Jet • Rocket engine • Steam engine • Stirling engine • Tschudi• Twingle Rotary • Wankel • Free-piston • Britalus • Coomber • Swing-piston • Orbital • Quasiturbine
Valves Cylinder head porting • D slide • Four-stroke • Manifold • Multi • Piston • Poppet • Sleeve
Piston layouts Single cylinder • Straight • Opposed • Flat • V • W • H • Deltic • Radial • Rocket engine nozzle • Rotary • Stelzer • Controlled Combustion • Bourke
Motion mechanisms Cam • Connecting rod • Coomber rotary • Crank • Crank substitute • Crankshaft • Linkages (Evans • Peaucellier-Lipkin • Sector straight-line • Watt) • Double acting/differential cylinder
Thermodynamic cycle