User:Yiba/sandbox

Lloyd M. Taylor
Lloyd M. Taylor was an American engineer lived in California in the 1930's through 1950's. He taught himself in the field of internal combustion engines, and was particularly interested in what makes an engine more efficient.

Fabricated Internal Combustion Engine
He learned that one of the important determinant of engine efficiency was compression ratio, and found through experiments that what is later called the "mechanical octane value" of a combustion chamber is the primary limiting factor. This means the rate at which a combustion chamber can dissipate heat determines how hot the internal surfaces of the chamber becomes, which, in turn determines the maximum compression ratio an engine designer could use.

In analysing the then-typical commercial water-cooled Otto cycle engines' cylinder blocks and cylinder heads made of cast iron with minimum wall thickness of about 1/4", Taylor concluded that there is not much room left for improvement in heat transfer from the chamber wall to the coolant.

After further experiments, he developed a new construction method for engine block and head to use various stamped steel plates of 1/16" to 1/8" thickness, together with cylinder sleeves, spark plug sleeves and valve guides, to form the entire engine, whereby the cylinder head and upper cylinder block sections have double wall construction to use the space in between as the coolant passage. This way, the heat on the combustion chamber wall would have incomparably shorter distance to travel to reach the coolant, thus a big improvement in mechanical octane value could be achieved.

Taylor applied for patent on April 8, 1941, and was issued the US Patent Number 2341488 "Fabricated Internal Combustion Engine" on February 8, 1944.

CoBra
Crosley developed a new manufacturing method called Copper Brazing (CoBra) where stamped steel plates and other pieces totalling some 125 are tack welded, press fit or crimped together, the entire structure is put in a specially made oven to be heated up to 2,060 degrees F and copper alloy brazing is applied to the seams. A cooling off method was carefully chosen to achieve the best final strength and hardness, and the result was not only of high mechanical octane value, but also extremely light in weight with its unitary cylinder head / block unit weighing only 14 lbs dry.

Formula One
In 1961, Coventry Climax was dominating the British Formula One field with the successful FPF and FWMV engines, but FWMV's initial selling price (3,000 Pounds), though considerably higher than the selling price of FPF (2,250 Pounds), did not cover the development cost and the mounting maintenance cost as more and more teams wanted to run it. He announced that the situation is the equivalent of his company subsidising the teams, so that the company will withdraw from Formula One racing at the end of the year.

As the customer teams did not have alternative engine suppliers, and thus being totally dependent on the supply of the FWMV engine, the teams got together and negotiated with Lee so that Oil company sponsorship funds would be funneled through the teams to Coventry Climax to cover the mounting costs, and Lee agreed to continue the development and support of these engines.

This incident became the seed for the formation of Formula One Constructors Association later in the 1970s.

Also see
Powel Crosley, Jr.

Early Types
The co-founders Keith Duckworth and Mike Costin, being former employees of Lotus Engineering Ltd., maintained a strong relationship with Colin Chapman and the initial revenues of the company came almost exclusively from Lotus. When the company was founded in 1958, only Keith Duckworth left Lotus, leaving Mike Costin who had signed a binding term-employment contract with Chapman. Until 1962, Mike Costin worked on Cosworth projects in his private time, active as a key Lotus engineer on Lotus 15 through Lotus 26 (Elan), as well as leading the on-track Team Lotus contingent at foreign races as evidenced by the famous 1962 Le Mans Lotus scandal.

The following is the list of initial products with cylinder heads modified, but not originally designed by Cosworth, on Ford Kent blocks. The exceptions were Mk.XVII and MAE, which had intake port sleeves for downdraft carburetors brazed into the stock cast iron head in place of the normal side draft ports. There also were some specially cast iron heads with similar dimensions to these brazed heads with Titanium alloy valve spring retainers called the 'Screamer Head' for MAE in later years. In addition to the above, Cosworth designed and provided the assembly work for Lotus Elan Special Equipment optional road engines with special camshafts and high compression pistons. No Wikipedia editor is allowed to climb the Reichstag building dressed as Spider-Man.

Hewland
Hewland is a British engineering company, founded in 1957 by Mike Hewland, which specialises in racing-car gearboxes. Although predated by Colotti in producing gearboxes for racing purposes, Hewland was the first UK company that made racing car transaxles.

History
Mike Hewland ran a small engineering business at Maidenhead in the UK with the specialty in gear cutting. In 1959, Bob Gibson-Jarvie, the Chief Mechanic of UDT Laystall racing team running Cooper F2 cars, sought help from Hewland as gearbox troubles were experienced. The result of this request came out as six successful gearboxes being designed and built in 1959, and Hewland was in the gearbox business.

The first transaxle product, the Hewland Mk.I of 1960, was a minor modification of the Volkswagen Beetle 4 speed transaxle used upside-down with custom made differential housing side plates for the midship engine Lola Mk.III (John Young tuned Ford 105E 997cc pushrod) built for the new Formula Junior rules (1L/360kg or 1.1L/400kg) in 1961. Hewland Mk.II was a similar 4 speed transaxle with more modifications for Coventry Climax engined Elva Mk.VI 1.1 Litre sports racer in 1961.

Hewland Mk.III of 1962 became the first product for the public, which utilised the magnesium alloy case of the Beetle transaxle to house 5 pairs of bespoke straight-cut constant mesh spur gears with motorcycle-style dog rings operated by custom-made brass shift forks. Gear selector shaft was located in the nose housing, unmodified as in the Beetle set up, facing rear-ward at the tail end of the box in the front-side-back position on a midship engine racing cars. The elimination of synchromesh parts provided the space for an additional pair of gears for the 5th speed.

This Mk.III became a big seller for small displacement formula cars and racing sports cars, and was the basis on which all the later products were built.

The advantages of the series were:
 * Dog-ring gear selection made it extremely quick shifting.
 * The structure that enabled changing of gear ratios on the 2nd through 5th speeds possible without removing the transaxle from the vehicle, or detaching it from the engine.
 * Upside-down usage enabled the dry sump racing engines to be mounted low on the chassis.
 * The 3rd, 4th and the 5th gears used the same components, thus were interchangeable.
 * Magnesium alloy Volkswagen case made it very light weight.

Hewland dominated the racing scenes in the 1960s, 70's, 80's and 90's, and still is a leading company in racing transmissions with its focus shifted a bit toward custom engineering work for vehicle manufacturers. In addition to the traditional manual transmission products covering almost all the racing and rallying classes, Hewland offers a complete semi-automatic transmission components including shift actuators, throttle actuators, compressors, shift position sensors and steering wheel paddle systems.

Transaxle types
The following is the list of the smaller product range housed in Volkswagen case except for LD200. Transmission capacity is measured by the maximum output torque (not the horsepower), which is the product of the input torque times overall reduction ratio. However, as the output torque is proportional to the input torque with typical gear and differential reduction ratios, and as the input torque (engine output torque) is roughly proportional to the engine displacement, Hewland used to indicate the maximum allowable engine size, and later the maximum input torque measured in Lbs/ft., as the transaxle selection guide.

The following is the list of larger product range up to 1981.

=Engine Balance= Engine balance refers to those factors in the design, production, tuning, maintenance and the operation of an engine that benefit from being balanced. Major considerations are:
 * Structural and operational elements within an engine
 * Longevity and performance
 * Power and efficiency
 * Performance and weight/size/cost
 * Environmental cost and utility
 * Noise/vibration and performance

This article is currently limited on structural and operational balance within an engine in general, and balancing of internal combustion piston engine components in particular.

Overview
Piston engine balancing is a complicated subject that covers many areas in the design, production, tuning and operation. The engine considered to be well balanced in a particular usage may produce unacceptable level of vibration in another usage for the difference in driven mass and mounting method, and slight variations in resonant frequencies of the environment and engine parts could be big factors in throwing a smooth operation off balance. In addition to the vast areas that need to be covered and the delicate nature, terminologies commonly used to describe engine balance are often incorrectly used and/or poorly defined not only in casual discussions but also in many articles on respected publications.

Internal combustion piston engines, by definition, are converter device to transform energy in intermittent combustion to mechanical motion. Slider-crank mechanism is used in creating a chemical reaction on fuel, and converting the energy into rotation.

This article lists the balancing elements in "Items to be balanced" section to establish the engine balance basics, followed by:
 * "Primary balance"
 * This section includes categorization of various kinds of engine vibration.


 * "Secondary balance"
 * This section explains what Secondary balance is, and how the confusing terminologies 'Primary' and 'Secondary' came into popular use.


 * "Inherent balance"
 * This section includes engine balance discussions on various multi-cylinder configurations.

Items to be balanced
There are many factors that could throw an engine off balance, and there are many ways to categorize them. The following is an example of categorizing the items that need to be balanced for a smooth running piston engine. As piston engine mechanisms are complex and have many components to balance, similar and often simpler categorizing principles can be used on many other forms of engines. In the category descriptions, 'Phase' refers to the timing on the rotation of crankshaft, 'Plane' refers to the location on the crankshaft rotating axis, and 'CG' refers to the center of gravity.


 * Mechanical
 * Static Balance - Static balance refers to the balancing of weight and the location of CG on moving parts.
 * 1. Reciprocating mass - e.g. Piston and conrod weight and CG uniformity.
 * 2. Rotating mass - e.g. Crank web weight uniformity and flywheel concentricity
 * Dynamic Balance - In order for a mass to start moving or change its course in the motion, it needs to be accelerated. In order for a mass to be accelerated, a force is required, and that force needs to be countered (supported) in the opposite direction. Dynamic balance refers to the balancing of these forces and friction.
 * All accelerations of a mass can be divided into two components opposing in the direction. For example, in order for a piston in a single cylinder engine to be accelerated upward, something must receive (support) the downward force, and it is usually the mass of the entire engine that moves downward a bit as there is no counter-moving piston.  This means one cause of engine vibration usually appears in two opposing directions.  Often the movement or deflection in one direction appears on a moving mass, and the other direction appears on the entire engine, but sometimes both sides appear on moving parts, e.g. a torsional vibration killing a crankshaft, or a push-pull resonance breaking a chain.  In other cases, one side is a deflection on a static part, the energy in which is converted into heat and dissipated into the coolant.
 * Reciprocating mass - Piston mass needs to be accelerated and decelerated, resisting a smooth rotation of a crankshaft. In addition to the up-down movement of a piston, a conrod bigend swings left and right on a typical single cylinder engine.
 * 3. Phase balance - e.g. Pistons on 90 degree V6 without a offset crankshaft reciprocate with unevenly spaced phases in a crank rotation
 * 4. Plane balance - e.g. Boxer Twin pistons travel on two different rotational planes on the crankshaft, which creates forces to rock the engine on Z-axis
 * Rotating mass
 * 5. Phase balance - e.g. Imbalance in camshaft rotating mass could generate a vibration with the frequency equal to 2 crank rotations in a 4 cycle engine
 * 6. Plane balance - e.g. Boxer Twin crankshaft without counter weights rocks the engine on Z-axis
 * 7. Torsional balance - e.g. If the rigidity of crank throws on an inline 4 cylinder engine is uniform, the crank throw farthest to clutch surface (#1 cylinder) normally shows the biggest torsional deflections, forcing the engine block to be twisted in the other rotational direction. It is usually impossible to make these deflections uniform across multiple cylinders except on a radial engine. See Torsional vibration
 * 8. Static mass - A single cylinder 10 HP engine weighing a ton is very smooth, because the forces that comprise its imbalance in the operation must move a large mass to create a vibration. As power to weight ratio is important in the design of an engine, the weight of a crankcase, cylinder block, cylinder head, etc. (i.e. static mass) are usually made as light as possible within the limitations of strength, cost and safety margin, and are often excluded in the consideration of engine balance.
 * However, most vibrations of an engine are small movements of the engine itself, and are thus determined by the engine weight, rigidity, location of CG, and how much its mass is concentrated around the CG. So these are crucial factors in engine dynamic balance, which is defined for the whole engine in reciprocal and rotational movements as well as in bending and twisting deflections on X, Y and Z axis.  It is important to recognize that some moving mass must be considered a part of static mass depending on the kind of dynamic balance consideration (e.g. camshaft weight in analyzing the Y axis rotational vibration of an engine).
 * Friction
 * 9. Slide resistance balance - e.g. A piston slides in a cylinder with friction. A ball in a ball bearing also slides as the diameter of inner and outer laces are different and the distance of circumference differs from the inside and out. When a ball bearing is used as the main bearing on a crankshaft, eccentricity of the laces normally create slide friction
 * 10. Rolling resistance balance - e.g. A ball in a ball bearing generates friction in rolling on a lace


 * Fluid - Pressure, Flow and Kinetic balance on gas, oil, water, mist, air, etc.
 * Torque Balance - Torque here refers to the torque applied to crankshaft as a form of power generation, which usually is the result of gas expansion. In order for the torque to be generated, that force needs to be countered (supported) in the opposite direction, so engine mounts are essential in power generation, and their design is crucial for a smooth running engine.
 * 11. Amount of torque - e.g. Normally, the amount of torque generated by each cylinder is supposed to be uniform within a multi-cylinder engine, but often are not
 * 12. Direction of torque - e.g. The conrod of a late-igniting cylinder pushes the crankshaft most at a different angle when compared to an early-igniting cylinder
 * 13. Phase balance - e.g. Firings on a single cylinder 4 cycle engine occur at every 720 degrees in crankshaft rotation
 * 14. Plane balance - e.g. Torque is applied to the crankshaft on the crank rotational plane where the conrod bigend is located, which are at different distances to power take off (e.g. clutch surface) plane on an inline multi-cylinder engine
 * Drag - Negative torque that resists the turning of crankshaft
 * Pressure balance - Not only the compression in a cylinder, but also any creation of positive (as in oil pressure) and negative (as in intake manifold) pressure are sources of resistance, which benefit from being uniform
 * 15. Phase balance - e.g. Compression on a single cylinder 4 cycle engine occurs every 720 degrees in crank rotation phase
 * 16. Plane balance - e.g. Compression on a boxer twin engine occurs at different planes on the crankshaft at different distance to clutch surface. A single plane (row) radial engine does not have this plane inbalance except for a short mismatch between the power generating plane where the conrods are, and the power take off plane where the propeller is.
 * Flow resistance
 * 17. Phase balance - e.g. If only one cylinder of a multi-cylinder engine has a restrictive exhaust port, this condition results in increased resistance every 720 degrees on crank rotation on a 4 cycle engine
 * 18. Plane balance - e.g. If only one cylinder of a multi-cylinder inline engine has a restrictive exhaust port, it results in increased resistance on the crank rotational plane where that cylinder/conrod is located.
 * 19. Kinetic resistance - Oil, water, vapor, gas and air do have mass, that needs to be accelerated in order to be moved for the operation of an engine. Rolls Royce Merlin received rear-facing stub exhaust pipes in its development, resulting in a measurable increase in the maximum speed of Supermarine Spitfire and De Havilland Mosquito.  This is a form of jet propulsion using kinetic energy in the exhaust, implying that the balancing of kinetic resistance arising from fluid components of an engine is not insignificant.  Crank webs partially hitting the oil in oil pan (accelerating the oil mass rapidly) could be a big source of vibration.
 * 20. Shearing resistance - Metallic parts in an engine are normally designed not to touch each other by being separated by a thin film of oil. But a cam sometimes touches the tappet, and metal bearing surface wears with insufficient oil or with too much / too little clearance.  A film of liquid (especially oil) resists being sheared apart, and this resistance could be a source of vibration as often experienced on an over-heating engine that is nearing a seizure.


 * 21. Thermal - Thermal balance is crucial for the durability of an engine, but also has a profound effect on many of the above balancing categories. For example, it is common for a longitudinary-mounted inline engines to have the front-most cylinder cooled more than the other cylinders, resulting in the temperature and torque generated on that cylinder less than on other phase and planes. Also, thermal inbalance creates variations in tolerances, creating differing sliding frictions.

Primary Balance
The terminology "Primary balance" is another source of confusion in the discussion of multi-cylinder piston engine configurations. Primary, "first order" or "first harmonic" balance are supposed to mean the same thing, and should refer to balancing of items that could shake an engine once in every rotation of the crankshaft, i.e. having the frequency equal to one crank rotation. Secondary or "second order" balance should refer to those items with the frequency of twice in one crank rotation, so there could be tertiary (third order), quaternary (fourth order), quinary (fifth order), etc. balances as well.

A cylinder in 4 cycle engines fires once in two crank rotations, generating forces with the frequency of a half the crankshaft speed, so the concept of "half order" vibrations is sometimes used when the discussion is on the balances on torque generation.

There are three major types of vibration caused by engine imbalances:

Reciprocating
A single cylinder, 360°-crank parallel twin, or a 180°-crank inline-3 engine normally vibrates up and down because there are no counter-moving piston(s) or there is a mismatch in the number of counter-moving pistons. This is a 3. phase imbalance of reciprocating mass.

Rocking
Boxer engines, 180°-crank parallel twin, 120°-crank inline-3, 90 degree V4, inline-5, 60 degree V6 and crossplane 90 degree V8 normally vibrate rotationally on Z or Y-axis. This is a result of plane imbalances (4., 6., 14. and 16) called the rocking couple.

Four stroke engines with 4 or less number of cylinders normally do not have overlapping power stroke, so tend to vibrate the engine back and forth rotationally on X-axis. Also, multi-cylinder engines with counter moving pistons have a CG height imbalance in a conrod swinging left on the top half of crank rotation, while another swings right on the bottom half, causing the top of the engine to move right while the bottom moves slightly to the left. Engines with 13. phase imbalance on torque generation (e.g. 90 degree V6, 180°-crank inline-3, etc.) show the same kind of rocking vibration on X-axis.

Torsional
Twisting forces on crankshaft cannot be avoided because conrods are normally located at a (often different) distance(s) to the power take-off plane (e.g. clutch surface) on the length of the crankshaft. The twisting vibrations caused by these (7.Torsional imbalance) forces normally cannot be felt outside of an engine, but are major causes of crankshaft failure.

However, it is simpler to focus on bigger sources of imbalance only, and it is somewhat customary to discuss only two categories, in which 'Primary' is traditionally meant to be all non-secondary imbalance items lumped together regardless of frequency, and 'Secondary' is meant to be the effects of non-sinusoidal component of piston and conrod motions in slider-crank mechanism as described below.

Secondary (Non-sinusoidal) Balance
When a crank moves 90 degrees from the top dead center (TDC) in a single cylinder engine positioned upright, the bigend up-down position is exactly at the half-way point in the stroke, but the conrod is at the most tilted position at this time, and this tilt angle makes the small-end position to be lower than the half-way point in the stroke.

Because the small-end position is lower than the half-way point of the stroke at 90 degrees and at 270 degrees after TDC, the piston moves less distance when the crank rotates from 90 degrees to 270 degrees after TDC than during the crank rotation from 90 degrees before TDC to 90 degrees after TDC. In other words, a piston must travel a longer distance in its reciprocal movement on the top half of the crank rotation, than on the bottom half.

Assuming the crank rotational speed to be constant, this means the reciprocating movement of a piston is faster on the top half than on the bottom half of the crank rotation. Consequently, the inertia force created by the mass of a piston (in its acceleration and deceleration) is stronger in the top half of the crank rotation than on the bottom half.

So, an ordinary inline 4 cylinder engine with 180 degrees up-down-down-up crank throw may look like cancelling the upward inertia created by the #1-#4 piston pair with the downward inertia of the #2-#3 pair and vice versa, but in fact the upward inertia is always stronger, and the vibration caused by this imbalance is traditionally called the Secondary Vibration.

When a conrod bigend rotates, its up-down movement (like it is seen from the side of an inline 4 cylinder engine) can be plotted on a graph (with the position on the stroke on Y-axis, rotational position of the crank in degrees on X-axis) with a clean Sine curve, and this is called the sinusoidal movement. Its left-right changes in position is exactly the same, as it is equivalent to just changing the view point from the side to the top of the engine. However, the up-down movement of a conrod small-end (and the piston) does not move in this fashion as described above, thus is considered not sinusoidal.

The inertia force created by this non-sinusoidal reciprocating motion is equivalent to the mass times the acceleration of change in the position, which is expressed as:
 * $$\Delta x = l + r \cos \Delta \alpha \,$$

where $$\Delta x$$ is the change in up-down location, $$l$$ is the center-to-center conrod length, $$r$$ is the radius of the crank (i.e. a half of stroke) $$\Delta \alpha$$ is the change in crank rotational angle from TDC.

This non-sinusoidal motion can mathematically be considered as a combination of two sinusoidal motions, one with the frequency equal to the crank rotation (equivalent to the piston motion with infinitely long conrod, which is called the 'primary' component), another with double the frequency (equivalent to the effect of conrod tilting angle, which is the 'secondary'). Although pistons do not move in the fashion defined by either of these two motions, it is easier to understand the motion separately, so the use of the terms primary and secondary became popular outside of mathematical analysis.

To live in the world without becoming aware of the meaning of the world is like wandering about in a great library without touching the books. - Dan Brown, 2009

The vibration caused by this inertia force (or the difference of its strength between the top and bottom half of crank rotation) is very small at lower engine speed, but it grows exponentially as it is proportional to the square of the crank rotational speed, making it a major problem in high-revving engines. Inline 4 cylinder and 90 degree V8 engines with flat-plane crankshaft move two pistons always in synch, making the imbalance twice as large (and a half as frequent) as in other configurations (e.g. Crossplane inline-four or V8) that move all pistons in different, evenly spaced, reciprocal phases.

Inherent balance
When comparing piston engines with different configurations in the number of cylinders, the V angle, etc., the term "inherent balance" is used. This term often describes just two categories in the above list that are 'inherent' in the configuration, namely, 3. (Phase balance on reciprocating mass), and 13. (Phase balance on torque generation).

In rare cases when considering a boxer twin, the categories 4. (Plane balance on reciprocating mass), 6. (Plane balance on rotating mass) and sometimes 14. (Plane balance on torque generation) are included, however, statements like "A flat-8 boxer engine has a perfect inherent balance" ignore these three categories as flat-8 boxer configuration has inherent imbalance in these categories by having the left and right banks staggered (not positioned symmetrically in plan view) in the same manner as in boxer twin.

"Inherent mechanical balance" further complicates the discussion in the use of the word 'mechanical' by implying to exclude balances on torque generation and compression for some people (as in the above categorization) while not excluding them for others (as they are the results of mechanical interaction among piston, conrod and crankshaft).

While many items on the above category list are not inherent to a configuration of a multi-cylinder engine, it is safe for a meaningful discussion of inherent balance on multi-cylinder engine configurations to include at least the balances on: and preferably:
 * Reciprocating mass (3.Phase and 4.Plane)
 * Rotating mass (6.Plane)
 * Torque generation (13.Phase and 14.Plane)
 * Compression (15.Phase and 16.Plane)

Two cylinder engines
There are three common configurations in two-cylinder engines: parallel-twin; V-twin; and boxer twin (a common form of flat engine).

Secondary imbalance is the strongest on a parallel twin with a 360 degree crankshaft (that otherwise has the advantage of 13. an evenly spaced firing, and lack of 4. & 6. imbalances), which moves two pistons together. Parallel twin with a 180 degree crankshaft (that has the disadvantage of 13. uneven firing spacing and strong 4., 6., 14. & 16. imbalance) produces the vibration a half as strong and twice as frequent. In a V-twin with a shared crank pin (e.g. Ducati 'L-twin'), the strong vibration of the 360°-crank parallel twin is divided into two different directions and phase separated by the same amount of degrees as in the V angle, with 13. unevenly spaced firing as well as the imbalances 4., 6., 14. and 16.

A boxer engine is a type of flat engine in which each of a pair of opposing cylinders is on separate crank throws, offset at 180° to its partner, with 13. an evenly spaced firing. If the pistons could lie on the same crank rotational plane, then the design is inherently balanced for the momentum of the pistons. But since they cannot, the design, despite having a perfect 3. phase balance largely cancelling the non-sinusoidal imbalance, inherently has 4. plane imbalance on reciprocating mass, 6. plane imbalance on rotating mass, 14. plane imbalance on torque generation, and 16. plane imbalance on compression (these four kinds of imbalance are also known as "rocking couple") due to the crank pin rotating planes being offset. [[

File:Forked connecting rods (Autocar Handbook, 13th ed, 1935).jpg|thumb|right|Fork and Blade conrods. This is the type used on Allison V-1710, which was retrofitted to many racing Merlins post-war.]]

This offset, the length of which partly determines the strength of the rocking vibration, is the largest on the parallel twin with a 180° crankshaft, and does not exist on a V or a flat engine that has a shared crank pin with "fork and blade" conrods (e.g. Harley-Davidson V-twin engine. See illustration on right). Other configurations fall in between, depending on the bigend and crank web thickness (if it exists in between the throws), and the main bearing width (if it exists in between the throws).

Three cylinder engines
Inline 3 with 120° crankshaft is the most common three cylinder engine. They have 13. evenly spaced firing and perfect 3. phase balance on reciprocating mass, with 4. plane imbalance on reciprocating mass, 6. plane imbalance on rotating mass, 14. plane imbalance on torque generation, and 16. plane imbalance on compression. Just like in a crossplane V8, these first order rocking couples can be countered with heavy counterweights, and the secondary balance is comparable to, or better than an ordinary inline 4 because there is no piston pairs that move together.

This secondary balance advantage is beneficial for making the engine compact, for there is not as much need for longer conrods, which is one of the reasons for the popularity of modern and smooth turbo-charged inline 3 cylinder engines on compact cars. However, the crankshaft with heavy counterweights tend to make it difficult for the engine to be made sporty (i.e. quick revving up and down) because of the strong flywheel effect.

Unlike in a crossplane V8, the bank of three cylinders have evenly spaced exhaust pulse 240° (120° if two stroke) crank rotational angle apart, so a simple three-into-one exhaust manifold can be used for uniform scavenging of exhaust (needed for uniform intake filling of cylinders, which is important for 11. and 12.), further contributing to the size advantage.

Four cylinder engines
Inline-4, flat-4 and V4 are the common types of four cylinder engine. Normal inline-4 configuration has very little rocking couples, but the secondary imbalance is large due to two pistons always moving together, and the rotational vibration on X-axis tend to be large because the height imbalance on conrods' CG swinging left and right is amplified due to two conrods moving together.

Ordinary Flat-4 boxer engines have excellent secondary balance at the expense of rocking couples due to opposing pistons being staggered (offset front to back). The above mentioned rotational vibration on X-axis is much smaller than an inline-4 because the pairs of conrods swinging up and down together move at different CG heights (different left-right position in this case). Another important imbalance somewhat inherent to boxer-four that is often not dialed out in the design is its irregular exhaust pulse on one bank of two cylinders. Please see flat-four burble explanation part of flat-four article on this exhaust requirement similar to the crossplane V8 exhaust peculiarity.

V4 engines come in vastly different configurations in terms of the 'V' angle and crankshaft shapes. Lancia Fulvia V4 engines with very narrow V angle have crank pin phase offset corresponding to the V angle, so the firing spacing (phase pattern) is exactly like an ordinary inline-four. But some V4s have irregular firing spacing, and each design needs to be considered separately in terms of all the balancing items. For example, Honda VFR1200F engine basically is a 76° V4 with a 360° shared-crank-pin crankshaft, but the conrod orientation is an unusual right-left-left-right (as opposed to normal right-left-right-left) with much wider bore spacing on the right bank than on the left, which results in significantly reduced rocking couples at the expense of longer engine length. Furthermore, the shared crank pin has 28° phase offset, resulting in 256°-104°-256°-104° firing spacing, which is irregular within a 360° crankshaft rotation but evenly distributed from one rotation to another (as opposed to 90° V4 with 180° crankshaft that has 180°-270°-180°-90° firing spaced unevenly within 360 degrees and within 720 degrees of crankshaft rotation).

Five cylinder engines
Inline five cylinger (L5) engine, with crank throws at 72° phase shift to each other, is the common five cylinder configuration. (Notable exceptions are Honda motorcycle V5, and Volkswagen VR5 engine.) These typical L5 engines have 13. evenly spaced firing and perfect 3. phase balance on reciprocating mass, with 4. plane imbalance on reciprocating mass, 6. plane imbalance on rotating mass, 14. plane imbalance on torque generation, and 16. plane imbalance on compression. Just like in inline 3 engines above, these first order rocking couples can be countered with heavy counterweights, and the secondary balance is comparable to, or better than an ordinary inline 6 because there is no piston pairs that move together.

Compared to three and four cylinder designs, a major advantage in 4-stroke format is the overlap in power stroke, where the combustion at every 144° of crank rotation ensures a continuous driving torque, which, while not as much noticeable at high rpm, translates to a much smoother idle.

Modern examples such as the current Audi RS3 engine have undersquare design, because the advantage in secondary balance allows it to have longer stroke without sacrificing the higher rpm smoothness, which is desirable for a smaller bore and shorter engine length.

Inline six cylinder engines
Inline 6 (L6), V6 and Flat 6 (F6) are the common six cylinder engine configurations.

Inline 6 normally has crank throws at 120° phase shift to each other with two pistons at about equal distance to the center of the engine (#1 and #6 cylinder, #2 and #5, #3 and #4) always moving together, which results in superb plane balance on reciprocating mass (4.) and rotating mass (6.), in addition to the perfect phase balances 3., 5., 13. and 15.. Combined with the overlapping torque generation at every 120° of crankshaft rotation, it often results in a very smooth engine at idle. However, the piston pairs that move together tend to make secondary imbalance strong at high rpm, and the long length configuration can be a cause for crankshaft and camshaft torsional vibration, often requiring a torsional damper. The long length of the engine often calls for a smaller bore and longer stroke for a given cylinder displacement, which is another cause for large secondary imbalance unless designed with long conrods. Furthermore, 4-stroke inline 6 engines inherently have 14. (Plane imbalance on torque generation) and 16. (Plane imbalance on compression), which are typically more or less balanced on 12 cylinder configurations.

In terms of firing spacing, these typical inline 6 are like two inline 3 engines connected in the middle, so the firing interval is evenly distributed within the front three cylinders and within the back three, with equal 240° spacing within the trio and 120° phase shift to each other. So three-into-one exhaust manifolds on the front and on the rear three cylinders, with each of them then connected with a two-into-one pipe results in 120° (240° if not merged in dual exhaust) evenly distributed exhaust pulse. Intake pulse, which is also important for evenly filling the cylinders with the same volume and mixture of intake charge for 11. (uniform amount of torque) and 12. (uniform timing in torque generation), is exactly the same, so two carburetors or throttle bodies on two one-into-three intake manifolds (when the three runner lengths are equal, strictly speaking) results in evenly spaced intake pulse at the throttles. Jaguar XK inline 6 had three SU carburettors each serving the front two, middle two and the rear two cylinders in the later models, which resulted in unevenly distributed intake pulse at each carburetor. This configuration, while resulting in higher power due to the increased total flow capacity of the carburetors than the earlier evenly-spaced-pulse twin carburetor configuration, may have contributed to the later 4.2 Liter version's "rougher running" reputation compared to the earlier legendary 3.4 and 3.8 Liter versions.

V6 engines
V6 engines with un-split shared crank pin can have equally spaced firing when the V-angle is at 120° (60° or 120° for 2-stroke). However, the 120° bank angle makes the engine rather wide, so production V6 tend to use 60° angle with a crank pin that is offset 60° for the opposing cylinders. As offsetting the crank pin for as much as 60° no longer provides overlap in the diameter of the crank pin, the actual pin is not really an offset 'split' pin, but normally is completely separate in two parts with a thin crank web connecting the two indivisual pins. This makes the crankshaft structurally weaker, much more so than in the crankshaft with slight offset seen on the Lancia Fulvia V4 with 10.5° to 13° offset, and racing V6 engines such as Cosworth GBA for Formula One often used the 120° bank angle to avoid this weakness unless required by the formula as in all the 2014 - 2015 Formula One 1.6 Liter turbo V6 engines that has 90° bank angle according to the regulation.

60° V6 is compact in length, width and height, which is advantageous for rigidity and weight. The short crankshaft length mitigates the torsional vibration problem, and secondary balance is better than in an inline 6 because there is no piston pairs that move together. Furthermore, each bank of three cylinders have evenly spaced ignition interval, so the exhaust system advantage is shared with inline 3. However, these advantages come at the price of having plane imbalances on 4. rotating mass, 6. reciprocating mass, 14. torque generation, and 16. compression. Also, the left and the right banks being staggered (for the thickness of a conrod plus the thin crank web) makes the reciprocating mass plane imbalance more difficult to be countered with heavy counterweights than in inline 3. But when the engine and engine mounts are properly designed, it makes a fabulous powerplant like Alfa Romeo V6 engines.

90° V6 simetimes were designed like chopping 2 cylinders off common V8 engines to share production tooling (e.g. General Motors 90° V6 engines up to 231 CID with 18° offset crankshaft and uneven firing interval), but newer examples (e.g. Honda C Series engines) are dedicated designs with 30° offset crank pins that result in even combustion spacing. Compared to 60° V6, the offset crank pins could have overlap in the diameter of the pin, and the V angle coincides with the angle of mean directions of conrods swinging left and right in each bank. It also shares the four (4., 6., 14 and 16.) plane imbalances (rocking couples) and the staggered cylinders, but there is the secondary balance advantage over L6 as well.

Flat six engines
Flat six engine with 180 degree phase offset between opposing cylinder pair, and 120 degree phase offset among the three pairs (these are called Boxer Six engine) is the common configuration. These 6 cylinder Boxer engines have 14. (Plane imbalance on torque generation) and 16. (Plane imbalance on compression) just like in inline six. As the strength of vibration generated by these imbalances are more or less proportional to engine length, boxer six has the advantage as flat-6 is much shorter than an inline 6 configuration. However, boxer six has additional plane imbalances on rotating mass (4.) and reciprocating mass (6.) due to its left and right banks being staggered front to back, although the offset distance tends to be much smaller in relation to the engine size than in flat-four and flat-twin.

On the other hand, secondary balance is far superior to Straight Six because there are no piston pairs moving together, and is superior to V6 because a large part of secondary imbalance is cancelled in the opposing cylinder pairs except for the front-to-back offset. This makes a boxer six particularly suited for high-revving operation.

Similar to Straight-six, these typical boxer 6 are like two inline 3 engines sharing a crankshaft, so the firing interval is evenly distributed within the three cylinders on the left bank and within the right three, with equal 240° spacing within the trio in a bank and 120° phase shift to each other. So three-into-one exhaust manifolds on the left and on the right three cylinders, with each of them then connected with a two-into-one pipe results in 120° (240° if not merged in dual exhaust) evenly distributed exhaust pulse. Likewise, intake pulse is evenly distributed among the three cylinders on each bank.

Porsche flat six engine is famous for being a successful design for a long production run, with some early examples (911T model) having a crankshaft without counter-weights.

List of Porsche engines
The following is the list of Porsche engines:

Early engines

 * Above engines after 1955 had 3-piece crankcase.

Piëch/Tomala/Mezger engine

 * SPM denotes Sportomatic. US denotes United States of America, includes Canada, excludes California after 1975.  CA denotes California.  ROW denotes "Rest of the World" excluding US, CA and Japan.

Mezger/Schäffer engine

 * N.A. denotes Normally Aspirated.

= 1934 Monaco Grand Prix =

The 1934 Monaco Grand Prix (formally the VI Grand Prix de Monaco) was a Grand Prix motor race held on 2 April 1934 at Circuit de Monaco in and out of Monte Carlo. The race comprised 100 laps of a 3.180km circuit, for a total race distance of 318.0km.

The Association Internationale des Automobile Clubs Reconnus (AIACR) had announced on 12 October 1932 that a new Grand Prix formula will go into effect for the 1934 season, and the 1934 Monaco Grand Prix was the first Grand Épreuve event run under the new regulations. Although one of the new rules required the race distance to be over 500 km, Monaco GP was permitted to be run for 100 laps or 318 km, as the time required to complete 100 laps at the slow Circuit de Monaco was comparable to 500 km at faster tracks such as Monza.

The race was won by Guy Moll, a newly recruited Algerian with Scuderia Ferrari, driving an Alfa Romeo Tipo B/P3. In addition to winning the very first race after the enrollment for Ferrari, Moll remained the youngest driver to have won a Monaco GP until Lewis Hamilton won in 2008.

Classification
Fastest Lap: Carlo Felice Trossi (Alfa Romeo Tipo B/P3), 2m00m00.0s

Aftermath
Chapman believed the fiasco was caused by the French contender for Index of Thermal Efficiency Award, René Bonnet. Gérard Crombac knew of a competitor to Bonnet, Jean Rédélé's ambition to beat the then-dominant Automobiles René Bonnet at Le Mans, and gave the idea of helping Alpine instead of subsequent direct participation to Chapman. As a result, a 2 seater racing prototype was designed by a team of Lotus employees, Len Terry, Bob Dance and Keith Duckworth based on Lotus 23C.

This design was found to be non-compliant to the 1963 Le Mans regulations, so the frame structure was changed to a steel backbone design familiar to Rédélé's team at Alpine, and became the Alpine M63. M64 of 1964 had the original frame designed by Terry, and the French Alpine M63 and M64 could fit British 6-stud Wobbly Web wheels as a testament.

In 1964 Le Mans, Alpine won the Index of Thermal Efficiency with the M64, with a M63B in the second place. Alpine went on to become the Le Mans overall winner in 1978 with a A442B.

The BDA series
Cosworth solidified its association with Ford in 1969, by developing a double overhead camshaft (DOHC) 16-valve inline four-cylinder engine for road use in the Ford Escort. As Keith Duckworth was busy designing and developing the DFV, the project was assigned to Mike Hall, who created the 1601 cc BDA on the Kent block for homologation purposes. The camshafts were driven by a toothed belt developed for Fiat 124, hence the name BDA, literally meaning "Belt Drive, A type". It was designed for FIA Group 2 and Group 4 on either rallying or touring car racing purpose. The nominal homologation at 1601 cc capacity meant that BDA-engined cars competed in what was usually the top class (1600 cc and up) so were eligible for overall victories rather than class wins.

In 1970, the 1701 cc BDB was created for the Escort RS1600, and this engine received fuel injection for the first time in the series as 1701 cc BDC. Two years later, the BDA series was adopted for Formula 2; first came the 1790 cc BDE, then the 1927 cc BDF eventually reaching a maximum of 1975 cc BDG in 1973. As the bore size reached ever closer to the bore center distance, leaving little space in between cylinders, the all three types had brazed-in cylinder liners to the block. As a departure from the Ford iron block, the BDG received a new aluminium block (originally designed by Brian Hart in 1971 and re-engineered by Cosworth ) soon after, and this cylinder block was used as a replacement part in rebuilding many other BD series engines as well as some Mk.XIII engines.

The iron block was also used for smaller displacements; starting with the very successful 1599 cc Formula Atlantic BDD in 1970, followed by the 1098 cc BDJ and 1300 cc BDH variants for SCCA Formula C and sports car racing, respectively. There was even a one-off 785 cc version built by Cosworth employees Paul Squires and Phil Kidsley; fitted with a Lysholm supercharger it was installed in a Brabham BT28 Formula 3 chassis and competed in the British Hill Climb Championship as the Brabham-Lysholm.

In 1970, Ford asked Weslake and Co of Rye to build the BDD for them, and by the end of 1970, the production line was installed at Rye and production was under way. These engines were often called the 'BDA', but were 1599 cc BDDs eligible for under 1.6 Litre class. The 1599 cc BDD engine won a number of championships around the world in Formula Atlantic and Formula Pacific during the 1980s.

In 1975, 1599 cc big valve BDM (225 bhp) was developed with fuel injection for Formula Atlantic, and a 'sealed engine' version BDN (1599 cc, 210 bhp) followed in 1977 for Canadian Formula Atlantic series.

Largely known as 'Cosworth BDA', BDD and BDM were also very successful in Formula Pacific and Formula Mondial racing in Australia and New Zealand. In open wheel racing, Cosworth powered cars (Ralt RT4 and Tiga's) won Australian Drivers' Championship from 1982-1986 as well as winning the Australian Grand Prix from 1981-1984 (including wins by Alain Prost and Roberto Moreno) before the race became part of the Formula One World Championship in 1985, and won the New Zealand Grand Prix each year from 1982-1988. BDD and BDM engines were also prominent in the Australian Sports Car Championship during the 1980s, winning the 1987 championship.

The turbo charged 1778 cc BDT was created in 1981, which powered the never-raced RWD Escort RS1700T. In 1984, 4WD Ford RS200 debuted with a 1803 cc version of BDT, which was created for Group B rallying. Between 1984 and 1986 the BDT engine was used in Group C endurance racing by Roy Baker, in class C2 using the Tiga GC284, GC285 and GC286. Later in 1986, a 2137 cc version was created by Brian Hart using a bespoke aluminium block and a large intercooler for RS200 Evolution, just as Group B was cancelled by the FIA. This BDT-E ('E' for Evolution) produced over 600 bhp in Group B 'rallycross' boost level, normally producing 530–550 bhp on a lower but sustainable boost.

In 1983, the BD series saw its second road engine incarnation (the first being the original BDA and BDB), the BDR, which was a BDA or BDB sold in kit form for the Caterham Super Seven in 1601 cc (120 bhp) and in 1701 cc (130 bhp) formats.

The Hart 420R and the Zakspeed F1 engines owe much to the BDA series, being essentially an aluminium-block derivative using similar heads.

Mercedes-Benz M276 engine
The first spray of fuel injection creates the base lean burn mixture in the intake cycle, while the later spray(s), up to 5 times in total in difficult conditions, control when and where the ignition starts and how the burn propagates in stratified charge fashion[3]. In combination with a new smaller and more efficient Variable Valve Timing mechanism on all 4 camshafts that enables short openings of intake valves with a longer combustion stroke, thus making the process an Atkinson Cycle in partial throttle conditions for better fuel efficiency, the precise control allows a quicker and smoother re-start of the engine for the Start-Stop system.

These features are also shared with Mercedes' M278 V8 engine, announced at the same time.

Partial Formula One Championship results

 * Constructor championship did not exist until.
 * Points are given on 8-6-4-3-2 basis down to 5th place. Only the best 6 races count.
 * Points are given on 8-6-4-3-2 basis down to 5th place. Only the best 5 races count.
 * Points are given on 8-6-4-3-2-1 basis down to 6th place. Only the best 6 races count.
 * Constructor championship points were not awarded for Indianapolis 500.
 * Brabham took over MacDowel's Cooper mid-race and finished 7th.
 * Moss participated these events with BRM.
 * Daigh drove for Scarab.
 * Phil Hill participated these events with Ferrari.
 * Brooks drove for Vanwall.
 * Salvadori drove Aston Martin DBR5.
 * Moss took over Trintignant's Cooper mid-race and finished 3rd.

Engine regulation progression
Notes: