Big-bang firing order
Encyclopedia
A big bang engine is an unconventional motorcycle engine
designed so that most of the power strokes occur simultaneously or in close succession. This is achieved by changing the ignition timing
; sometimes in combination with a change in crankpin angle. The goal is to change the power delivery characteristics of the engine or exhaust sound. A regular firing multi-cylinder engine fires at approximately even intervals, giving a smooth-running engine. Because of a big bang engine's power delivery imbalance, there exists more vibration and stress in the engine. This imbalance can overwhelm the rear tire, and generally makes a slide harder to catch. Until recently, this has limited their use to racing.
, Triumph, Norton, AJS
& Matchless
) had a 360° crankshaft that, compared to a single, gave twice as many ignition pulses, which were evenly spaced.
The early Japanese parallel twins, like the 1966 Honda “Black Bomber” and Yamaha TX500
, adopted a 180° crank that gave an uneven firing pattern. This configuration has the best possible primary mechanical engine balance
for a parallel twin; the uneven firing was a by-product of this design.
The Yamaha TRX850 had a 270° crank that allowed a more regular firing pattern than a 180° crank, and less regular than a 360° crank. This configuration has the best possible secondary engine balance
for a parallel twin; its exhaust sound and power delivery is identical to a 90° V-twin.
designed to give power pulses similar to a single cylinder four-stroke engine. It is well known that four-stroke singles "hook up" better than two-strokes in the dirt. This is because four-stroke singles have half as many power strokes per crankshaft revolutions as a two-stroke single. This creates a recovery gap during which the rear tire regains traction.
Inline twins with a 360° crankpin offset or flat-twin
s can be easily converted into twingles by firing both of the cylinders at the same time and installing a camshaft or camshafts that operate both cylinders' valves in parallel. Because many such engines already employ the wasted spark
principle, only the camshaft modification is necessary.The Vintage Dirt Track Racing Association (VDTRA) 2010 Rules have banned vintage motorcycles from being setup as a twingle.
naturally has slightly uneven spaced power strokes. By changing the ignition timing
on one of the cylinders by 360° the power stroke
s are very closely spaced. This will cause uneven fuel distribution in an engine with a single carburettor. The Harley-Davidson XR-750
with twin carburettors was a popular bike to twingle. It had great success in flattrack racing.
The 2009 Yamaha YZF-R1
has instead an uneven firing order. The power delivery is the same as a 90° V4 with a 180° crank, such as the Honda VFR800
and very similar to the Yamaha V-Max
which has been lauded for its exhaust sound.
began and ended its life as a screamer. However in 1990 Honda connected both of the pistons in one bank to the same crankpin and both of the other pistons to a crankpin offset 180°. This NSR500 was called a 'big bang'. Yamaha created a big bang YZR500 in 1992. The YZR500 had two crankshafts like a U engine
and the angle between each pair of cylinders was 90°, like a V4.
In 1997 Mick Doohan wanted to run a 180° screamer engine. HRC
crew chief Jerry Burgess explains why: "The 180 got back a direct relationship between the throttle and the rear wheel, When the tire spun I could roll off without losing drive. The big bang has a lot of engine braking, so it upsets the bike into corners, then when you open the throttle you get this sudden pulse of power, which again upsets the suspension. Mick's secret is corner speed, so he needs the bike to be smooth and the 180 is much smoother."
Motorcycle engine
A motorcycle engine is an engine that powers a motorcycle.Motorcycle engines may be two-stroke or four-stroke, reciprocating or Wankel, single-cylinder or multicylinder , or single-rotor or twin-rotor . The engine typically drives the rear wheel, but some small bikes such as the Velosolex have a...
designed so that most of the power strokes occur simultaneously or in close succession. This is achieved by changing the ignition timing
Ignition timing
Ignition timing, in a spark ignition internal combustion engine , is the process of setting the angle relative to piston position and crankshaft angular velocity that a spark will occur in the combustion chamber near the end of the compression stroke...
; sometimes in combination with a change in crankpin angle. The goal is to change the power delivery characteristics of the engine or exhaust sound. A regular firing multi-cylinder engine fires at approximately even intervals, giving a smooth-running engine. Because of a big bang engine's power delivery imbalance, there exists more vibration and stress in the engine. This imbalance can overwhelm the rear tire, and generally makes a slide harder to catch. Until recently, this has limited their use to racing.
Twins and twingles
| Engine | Crankshaft | Ignition timing | Graphical | Example |
|---|---|---|---|---|
| Single (2-stroke) Parallel twin Flat twin |
360° 180° |
360-360 | 1-0-0-0-1-0-0-0- | BSA BSA -Organizations:* Baltimore School for the Arts* Bank Secrecy Act* Bearing Specialists Association* Belarusian Socialist Assembly* Bhutan Scouts Association* Bibliographical Society of America* Birmingham School of Acting... , Triumph, Norton, AJS AJS AJS was the name used for cars and motorcycles made by the Wolverhampton, England, company A. J. Stevens & Co. Ltd, from 1909 to 1931, by then holding 117 motorcycle world records, and after the firm was sold the name continued to be used by Matchless, Associated Motorcycles and Norton-Villiers on... , Matchless Matchless Matchless is one of the oldest marques of British motorcycles, manufactured in Plumstead, London, between 1899 and 1966. A wide range of models was produced under the Matchless name, ranging from small two-strokes to 750 cc four-stroke twins... and BMW F800S BMW F800S The F800S was a sport bike made by BMW Motorrad from 2006 to 2010. Along with the F800S, other bikes in the F-bike range are the dual-sport F800GS, the sport touring F800ST, and the naked F800R.... BMW R series |
| Single Parallel twingle Flat twingle |
360° 180° |
720 | 1-0-0-0-0-0-0-0- 2-0-0-0-0-0-0-0- 2-0-0-0-0-0-0-0- |
|
| Parallel twin | 180° | 180-540 | 1-0-1-0-0-0-0-0- | 1966 Honda “Black Bomber”, Yamaha TX500 Yamaha TX500 The Yamaha TX500 was a café racer style motorcycle built by Yamaha in 1973 and 1974. It closely resembled the Triumph Bonneville in style and in its 180º parallel twin engine. The TX500 engine was fairly advanced for its time with dual overhead cams and four valves per cylinder, making it both... and Kawasaki ER-6 |
| Parallel twin 90° V twin |
270° 360° |
270-450 | 1-0-0-1-0-0-0-0- | Yamaha TRX850 Triumph Thunderbird (since 2009) Ducati Triumph Scrambler Triumph Scrambler The Triumph Scrambler is a British motorcycle made by Triumph Motorcycles. Launched in 2006, it was the last Triumph styled by designer John Mockett, who had begun working with the small factory team at Triumph in 1989, rationalising existing models based on a very successful modular design plan,... |
| 45° V twin | 360° | 315-405 | 1-0-0-010-0-0-0- | Harley-Davidson Harley-Davidson Harley-Davidson , often abbreviated H-D or Harley, is an American motorcycle manufacturer. Founded in Milwaukee, Wisconsin, during the first decade of the 20th century, it was one of two major American motorcycle manufacturers to survive the Great Depression... |
| 45° V twingle | 360° | 45-675 | 110-0-0-0-0-0-0- | Modified Harley-Davidson XR-750 Harley-Davidson XR-750 The XR-750 is a Harley-Davidson racing motorcycle made since 1970, primarily for dirt track racing, but also for road racing in the XRTT variant... for flat track racing |
Parallel twins
The classic British parallel twins (BSABSA
-Organizations:* Baltimore School for the Arts* Bank Secrecy Act* Bearing Specialists Association* Belarusian Socialist Assembly* Bhutan Scouts Association* Bibliographical Society of America* Birmingham School of Acting...
, Triumph, Norton, AJS
AJS
AJS was the name used for cars and motorcycles made by the Wolverhampton, England, company A. J. Stevens & Co. Ltd, from 1909 to 1931, by then holding 117 motorcycle world records, and after the firm was sold the name continued to be used by Matchless, Associated Motorcycles and Norton-Villiers on...
& Matchless
Matchless
Matchless is one of the oldest marques of British motorcycles, manufactured in Plumstead, London, between 1899 and 1966. A wide range of models was produced under the Matchless name, ranging from small two-strokes to 750 cc four-stroke twins...
) had a 360° crankshaft that, compared to a single, gave twice as many ignition pulses, which were evenly spaced.
The early Japanese parallel twins, like the 1966 Honda “Black Bomber” and Yamaha TX500
Yamaha TX500
The Yamaha TX500 was a café racer style motorcycle built by Yamaha in 1973 and 1974. It closely resembled the Triumph Bonneville in style and in its 180º parallel twin engine. The TX500 engine was fairly advanced for its time with dual overhead cams and four valves per cylinder, making it both...
, adopted a 180° crank that gave an uneven firing pattern. This configuration has the best possible primary mechanical engine balance
Engine balance
Engine balance is the design, construction and tuning of an engine to run smoothly. Improving engine balance reduces vibration and other stresses and can improve the overall performance, efficiency, cost of ownership and reliability of the engine, as well as reducing the stress on other machinery...
for a parallel twin; the uneven firing was a by-product of this design.
The Yamaha TRX850 had a 270° crank that allowed a more regular firing pattern than a 180° crank, and less regular than a 360° crank. This configuration has the best possible secondary engine balance
Engine balance
Engine balance is the design, construction and tuning of an engine to run smoothly. Improving engine balance reduces vibration and other stresses and can improve the overall performance, efficiency, cost of ownership and reliability of the engine, as well as reducing the stress on other machinery...
for a parallel twin; its exhaust sound and power delivery is identical to a 90° V-twin.
Twingles
A twingle is a four-stroke twin-cylinder engine with an altered firing orderFiring order
The firing order is the sequence of power delivery of each cylinder in a multi-cylinder reciprocating engine.This is achieved by sparking of the spark plugs in a gasoline engine in the correct order, or by the sequence of fuel injection in a Diesel engine...
designed to give power pulses similar to a single cylinder four-stroke engine. It is well known that four-stroke singles "hook up" better than two-strokes in the dirt. This is because four-stroke singles have half as many power strokes per crankshaft revolutions as a two-stroke single. This creates a recovery gap during which the rear tire regains traction.
Inline twins with a 360° crankpin offset or flat-twin
Flat-twin
A flat-twin is a two cylinder internal combustion engine with the cylinders arranged on opposite sides of the crankshaft. It is part of the class of flat engines, sub-type "boxer", and shares most characteristics of those engines.-Motorcycle use:...
s can be easily converted into twingles by firing both of the cylinders at the same time and installing a camshaft or camshafts that operate both cylinders' valves in parallel. Because many such engines already employ the wasted spark
Wasted spark
The wasted spark system is an ignition system used with some four-stroke cycle internal combustion engines. In a wasted spark system, the spark plugs fire in pairs even though one is on its compression stroke and one is on its exhaust stroke. The extra spark on the exhaust stroke has no effect and...
principle, only the camshaft modification is necessary.The Vintage Dirt Track Racing Association (VDTRA) 2010 Rules have banned vintage motorcycles from being setup as a twingle.
V twins
A narrow angle v-twin such as the 45° Harley-DavidsonHarley-Davidson
Harley-Davidson , often abbreviated H-D or Harley, is an American motorcycle manufacturer. Founded in Milwaukee, Wisconsin, during the first decade of the 20th century, it was one of two major American motorcycle manufacturers to survive the Great Depression...
naturally has slightly uneven spaced power strokes. By changing the ignition timing
Ignition timing
Ignition timing, in a spark ignition internal combustion engine , is the process of setting the angle relative to piston position and crankshaft angular velocity that a spark will occur in the combustion chamber near the end of the compression stroke...
on one of the cylinders by 360° the power stroke
Power stroke
Power Stroke may refer to:In motoring:*Power stroke , the stroke of a cyclic motor which generates force*Ford Power Stroke engine, Ford diesel engineOther:*In baseball, a batter who hits for extra bases is said to have a power stroke...
s are very closely spaced. This will cause uneven fuel distribution in an engine with a single carburettor. The Harley-Davidson XR-750
Harley-Davidson XR-750
The XR-750 is a Harley-Davidson racing motorcycle made since 1970, primarily for dirt track racing, but also for road racing in the XRTT variant...
with twin carburettors was a popular bike to twingle. It had great success in flattrack racing.
Four-cylinder engines
| Engine | Crankshaft | Ignition timing | Graphical | Example |
|---|---|---|---|---|
| I4 | 180° | 180-180-180-180 | 1-0-1-0-1-0-1-0- | Honda CB750 Honda CB750 The Honda CB750 is a motorcycle built in several model series between 1969 and 2003 and 2007 that is recognized as a milestone for Honda's successful introduction of a transverse, overhead camshaft inline four-cylinder engine that has ever since been the dominant sport bike configuration... |
| I4 'Long bang' | 180° | 180-540 | 2-0-2-0-0-0-0-0- | Shinya Nakano's Kawasaki Ninja ZX-RR |
| I4 'Uneven bang' | crossplane Crossplane The crossplane or cross-plane is a crankshaft design for V8 engines with a 90° angle between the cylinder banks.The crossplane crankshaft has four crankpins, each offset at 90° from the adjacent crankpins... |
180-90-180-270 | 1-0-1-1-0-1-0-0- | 2009 Yamaha YZF-R1 Yamaha YZF-R1 The Yamaha YZF-R1 is an open class sport bike, or superbike, motorcycle manufactured by Yamaha Motor Company since 1998.-1998–1999:Yamaha launched the YZF-R1 after redesigning the Genesis engine to offset the crankshaft, gearbox input, and output shafts. This "compacting" of the engine made the... |
| 70° V4 90° V4 |
180° | 180-70-180-290 180-90-180-270 |
1-0-1-1-0-1-0-0- | 1985-2007 Yamaha V-Max Honda VFR800 Honda VFR800 The Honda VFR800, also known as the Interceptor, is a motorcycle introduced by Honda in 1998. It is a successor to the VFR750F , which was preceded by the VF750.From its first sales in 1986, the VFR750F scored highly on many press reviews... |
| 90° V4 'Twin pulse' |
70° | 90-200-90-340 | 1-1-0-1-1-0-0-0- | Ducati Desmosedici RR Ducati Desmosedici RR The Ducati Desmosedici RR is a limited production road-legal version of the Desmosedici MotoGP racebike.Ducati made 1,500 Desmosedici models for public purchase. The bike was launched at the 2006 Italian MotoGP event... |
| 90° V4 'Droner' | 360° | 90-270-90-270 | 1-1-0-0-1-1-0-0- | Honda VF/RC30 Honda VFR750R The Honda VFR750R, frame designation RC30, was a fully faired racing motorcycle created for homologation purposes for the World Superbike championship by Honda Racing Corporation . It was first released to the Japanese market in 1987. American enthusiasts had to wait until 1990 to get their hands... /RC45 Honda RVF750 RC45 The Honda RVF750R RC45 was a fully faired racing motorcycle created for homologation purposes for the Superbike World Championship by Honda Racing Corporation. The RVF750R was the successor to the VFR750R RC30... |
| 112° V4 'Big bang' (2-stroke) | 180° | 68-292-68-292 | 2-2-0-0-2-2-0-0- | 1990 Honda NSR500 Honda NSR500 thumb|right|Shinichi Itoh, riding his Honda NSR500 in the Japanese Grand Prix 1993The Honda NSR500 is a race motorcycle from the Honda NSR series. It was created by HRC and debuted in 1984 for the Grand Prix motorcycle racing's 500 cc class. Honda won ten 500cc World Championships with the... |
| 90° V4 'Screamer' (2-stroke) | 180° | 90-90-90-90-90-90-90-90 | 1-1-1-1-1-1-1-1- | 1984 Honda NSR500 Honda NSR500 thumb|right|Shinichi Itoh, riding his Honda NSR500 in the Japanese Grand Prix 1993The Honda NSR500 is a race motorcycle from the Honda NSR series. It was created by HRC and debuted in 1984 for the Grand Prix motorcycle racing's 500 cc class. Honda won ten 500cc World Championships with the... |
Inline fours
A four-cylinder engine with a regular firing interval is sometimes referred to as a screamer. The regular delivery of power strokes can overwhelm the rear tire, and generally makes a slide harder to catch as well. A long bang fires both pairs of cylinders in quick succession; the power delivery is identical to a parallel twin with a 180° crank and similar to a v-twin. In 2005 Kawasaki experimented with this configuration on the ZX-RR MotoGP bike.The 2009 Yamaha YZF-R1
Yamaha YZF-R1
The Yamaha YZF-R1 is an open class sport bike, or superbike, motorcycle manufactured by Yamaha Motor Company since 1998.-1998–1999:Yamaha launched the YZF-R1 after redesigning the Genesis engine to offset the crankshaft, gearbox input, and output shafts. This "compacting" of the engine made the...
has instead an uneven firing order. The power delivery is the same as a 90° V4 with a 180° crank, such as the Honda VFR800
Honda VFR800
The Honda VFR800, also known as the Interceptor, is a motorcycle introduced by Honda in 1998. It is a successor to the VFR750F , which was preceded by the VF750.From its first sales in 1986, the VFR750F scored highly on many press reviews...
and very similar to the Yamaha V-Max
Yamaha V-Max
The V-Max, called the VMAX since 2008, is a cruiser motorcycle made by Yamaha since 1985, known for its powerful V4 engine, shaft drive, and distinctive styling.-History:...
which has been lauded for its exhaust sound.
2-stroke V4
The Honda NSR500Honda NSR500
thumb|right|Shinichi Itoh, riding his Honda NSR500 in the Japanese Grand Prix 1993The Honda NSR500 is a race motorcycle from the Honda NSR series. It was created by HRC and debuted in 1984 for the Grand Prix motorcycle racing's 500 cc class. Honda won ten 500cc World Championships with the...
began and ended its life as a screamer. However in 1990 Honda connected both of the pistons in one bank to the same crankpin and both of the other pistons to a crankpin offset 180°. This NSR500 was called a 'big bang'. Yamaha created a big bang YZR500 in 1992. The YZR500 had two crankshafts like a U engine
U engine
A U engine is a piston engine made up of two separate straight engines joined by gears or chains. It is similar to the H engine which couples two flat engines...
and the angle between each pair of cylinders was 90°, like a V4.
In 1997 Mick Doohan wanted to run a 180° screamer engine. HRC
Honda Racing Corporation
Honda Racing Corporation is a division of the Honda Motor Company formed in 1982. The company combines participation in motorcycle races throughout the world with the development of high potential racing machines. Its racing activities are an important source for the creation of leading edge...
crew chief Jerry Burgess explains why: "The 180 got back a direct relationship between the throttle and the rear wheel, When the tire spun I could roll off without losing drive. The big bang has a lot of engine braking, so it upsets the bike into corners, then when you open the throttle you get this sudden pulse of power, which again upsets the suspension. Mick's secret is corner speed, so he needs the bike to be smooth and the 180 is much smoother."