
The
Ford Model T
The Ford Model T is an automobile that was produced by Ford Motor Company from October 1, 1908, to May 26, 1927. It is generally regarded as the first affordable automobile, which made car travel available to middle-class Americans. The relat ...
used a
sidevalve,
reverse-flow cylinder head inline 4-cylinder engine. It was primarily a
gasoline engine
A petrol engine (gasoline engine in American English) is an internal combustion engine designed to run on petrol (gasoline). Petrol engines can often be adapted to also run on fuels such as liquefied petroleum gas and ethanol blends (such as '' ...
. It produced for a top speed of . It was built in-unit with the Model T's novel
transmission (a
planetary design), sharing the same
lubricating oil
A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, t ...
.
The T engine was known for its simplicity, reliability, and economy. The engine remained in production for many years, and millions of units were produced. The engine design's lifespan exceeded that of the Model T vehicle itself, with industrial, marine, and military applications extending its production run. The T engine is on the
Ward's 10 Best Engines of the 20th Century list.
Fuel choices and fuel economy
The Model T engine was built as a
gasoline engine
A petrol engine (gasoline engine in American English) is an internal combustion engine designed to run on petrol (gasoline). Petrol engines can often be adapted to also run on fuels such as liquefied petroleum gas and ethanol blends (such as '' ...
. While not engineered specifically for
multifuel ability, its simple, robust design allowed a modified engine to successfully run on a variety of combustible fuels including
benzene
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen ato ...
,
ethanol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a h ...
, or
kerosene
Kerosene, paraffin, or lamp oil is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from el, κηρός (''keros'') meaning " wax", and was reg ...
. According to Ford Motor Company, the Model T had fuel economy on the order of .
Carburetor and fuel system

The Ford Model T engine had one
carburetor
A carburetor (also spelled carburettor) is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the venturi tube in the main meter ...
, a side-draft, single-
venturi unit. Its
choke and
throttle valves were controlled manually; the latter was with a hand lever rather than a foot pedal. The carburetor had no accelerator pump. Various vendors supplied Ford with carburetors for the T engine, including
Holley,
Zenith
The zenith (, ) is an imaginary point directly "above" a particular location, on the celestial sphere. "Above" means in the vertical direction ( plumb line) opposite to the gravity direction at that location ( nadir). The zenith is the "high ...
, and Kingston.
During most of the T's production run, its fuel tank was mounted to the frame beneath the front seat. Because Ford relied on gravity to feed fuel to the carburetor rather than a
fuel pump, a Model T could not climb a steep hill when the fuel level was low. The immediate solution was to climb steep hills in reverse. In 1926, the fuel tank was moved forward and upward, under the cowl, behind the dashboard on most models,
which improved the gravity feed. Less than surprisingly installing an after market fuel pump was a near ubiquitous modification made to the Ford's original, extremely spartan, engine design. The engine is in many ways a half-manufacture even by the standards of its day when it came to internal combustion engine thermal efficiency and refined running characteristics, which are necessary to lengthen the unit's life span and also to make the most of resources used to manufacture the entire car. The Model T components were made to wide tolerances to accommodate manufacturing techniques of the day to produce reliable devices, and in making these components, the Ford Motor Company engineers used, from a modern perspective, extremely high levels of over tolerance to assure endurance of the end product.
Since it was up to the end-user to effectively finish what Ford's assembly line left unfinished, while ingratiating him with munificent amounts of material to work with, the Ford Model T gave birth to the modern aftermarket performance engineering market. Later, with the introduction of the Model A,
Ford's flathead V8 in the early 30's, and their ease of availability in the post-war 1940's and early 1950's at a price that was within the reach of teenagers, mating one to a salvageable example of a Model T or a Model A lacking this eight cylinder engine gave birth to
Hot Rod
Hot rods are typically American cars that might be old, classic, or modern and that have been rebuilt or modified with large engines optimised for speed and acceleration. One definition is: "a car that's been stripped down, souped up and made ...
culture in the early 40's.
Internal design

The T engine was an
inline-four, with all four
cylinders
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base.
A cylinder may also be defined as an infini ...
cast into one
engine block
In an internal combustion engine, the engine block is the structure which contains the cylinders and other components. In an early automotive engine, the engine block consisted of just the cylinder block, to which a separate crankcase was attac ...
. Such
monobloc design was an uncommon practice when T production started in 1908. It lent itself to
mass production, showing the Ford company's prescient focus on
design for manufacturability
Design for manufacturability (also sometimes known as design for manufacturing or DFM) is the general engineering practice of designing products in such a way that they are easy to manufacture. The concept exists in almost all engineering discipli ...
. The
head
A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may no ...
, however, was detachable, which not only aided Ford in manufacturing but also made valve jobs (cleaning, grinding, or replacement of the
poppet valve
A poppet valve (also called mushroom valve) is a valve typically used to control the timing and quantity of gas or vapor flow into an engine.
It consists of a hole or open-ended chamber, usually round or oval in cross-section, and a plug, usual ...
s) easier. The block and head were both of
cast iron
Cast iron is a class of iron– carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impu ...
.
The engine's
bore
Bore or Bores often refer to:
*Boredom
* Drill
Relating to holes
* Boring (manufacturing), a machining process that enlarges a hole
** Bore (engine), the diameter of a cylinder in a piston engine or a steam locomotive
** Bore (wind instruments), ...
was and its
stroke was even, for a total
displacement of . The compression ratio was 3.98 for most engines; early engines were slightly greater. This value is low by modern standards but was typical for the era, making the engine forgiving of poor-quality, low-octane fuel and minimizing cranking effort at starting.
The
valvetrain was a side valve (
flathead) design.
The
crankshaft had 3
main bearing
Main may refer to:
Geography
*Main River (disambiguation)
**Most commonly the Main (river) in Germany
* Main, Iran, a village in Fars Province
*" Spanish Main", the Caribbean coasts of mainland Spanish territories in the 16th and 17th centuries ...
s.
Cooling system

The T engine's
cooling system reflected the T's simplicity design theme. The first few hundred Model Ts had a water pump, but it was eliminated early in production. Instead, Ford opted for a cheaper and more reliable
thermosyphon system. Thermosyphon was a common engine-cooling method of the era. Hot water, being less dense, would rise to the top of the engine and up into the top of the radiator, descending to the bottom as it cooled, and back into the engine. (This was the direction of water flow in most cars which did have water pumps, until the introduction of
crossflow radiator designs.) The thermosiphon system was susceptible to overheating if worked heavily, but served well for most Model T usage.
Many types of water pumps were available as aftermarket accessories.
Ignition system

The Model T engine's
ignition system
An ignition system generates a spark or heats an electrode to a high temperature to ignite a fuel-air mixture in spark ignition internal combustion engines, oil-fired and gas-fired boilers, rocket engines, etc. The widest application for spark ig ...
used a
flywheel-mounted
magneto
A magneto is an electrical generator that uses permanent magnets to produce periodic pulses of alternating current. Unlike a dynamo, a magneto does not contain a commutator to produce direct current. It is categorized as a form of alternator, ...
to produce the
current necessary to produce a spark to initiate combustion. This current was distributed by the timer (analogous to a
distributor
A distributor is an enclosed rotating switch used in spark-ignition internal combustion engines that have mechanically timed ignition. The distributor's main function is to route high voltage current from the ignition coil to the spark p ...
in a modern vehicle) to one of the four
trembler coils, one for each
cylinder
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base.
A cylinder may also be defined as an infi ...
. The coil stepped up the
voltage
Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge t ...
and discharged it to the
spark plug
A spark plug (sometimes, in British English, a sparking plug, and, colloquially, a plug) is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air ...
in the cylinder. Ignition timing was adjusted manually by using the spark advance lever mounted on the steering column, which rotated the timer, advancing or retarding the
ignition timing
In a spark ignition internal combustion engine, ignition timing is the timing, relative to the current piston position and crankshaft angle, of the release of a spark in the combustion chamber near the end of the compression stroke.
The need f ...
. A certain amount of skill and experience was required to find the optimal spark timing for any speed and load.
The magneto was the first Model T component to be assembled on an
assembly line
An assembly line is a manufacturing process (often called a ''progressive assembly'') in which parts (usually interchangeable parts) are added as the semi-finished assembly moves from workstation to workstation where the parts are added in sequ ...
, and the method was copied to many other Model T production segments. The ignition system of the
Fordson tractor was similar to the Model T's.
Electrical System
In the early years of Model T production, all engines were started with a hand
crank
Crank may refer to:
Mechanisms
* Crank (mechanism), in mechanical engineering, a bent portion of an axle or shaft, or an arm keyed at right angles to the end of a shaft, by which motion is imparted to or received from it
* Crankset, the compone ...
. A battery could be used to supply ignition current for starting, since it could be difficult to hand-crank a very cold engine fast enough for the magneto to produce sufficient current. However, although all Model T's had a "BAT" (battery) position on the coil box switch and a corresponding terminal on the box. Ford did not supply or even encourage the use of a battery before 1919, when it introduced a battery-driven
electric starter. Even this was not standard equipment for all models until sometime in 1926, the last year of production.
Most cars sold after 1919 were equipped with this starter, which was engaged by a small round foot-operated button switch on the floor. These cars included a battery and a
generator for recharging it. In keeping with the goal of reliability and simplicity, the trembler coil and magneto ignition system was retained even on cars with the starter system.
When electric
headlights
A headlamp is a lamp attached to the front of a vehicle to illuminate the road ahead. Headlamps are also often called headlights, but in the most precise usage, ''headlamp'' is the term for the device itself and ''headlight'' is the term f ...
were introduced in 1915, the magneto was upgraded to supply enough power for the lights and horn. If a Model T had an electric starter equipped, the upgraded electrical system would also be used to supply power to these items.
Operation

Operating the T engine was not difficult after some experience, although the learning curve was longer than today's. The various manual control tasks (such as manual choke and spark advance) and the method of use (such as hand throttle) were typical for automobiles of the era, although they might seem more like farm tractor operation to most automobile drivers of today.
Before starting a Model T with the
hand crank
A crank is an arm attached at a right angle to a rotating shaft by which circular motion is imparted to or received from the shaft. When combined with a connecting rod, it can be used to convert circular motion into reciprocating motion, or vice ...
, the spark had to be manually retarded or the engine might "kick back". The crank handle was cupped in the palm, with the thumb tucked under the handle (not clasped over top of it), so that if the engine did kick back, the rapid reverse motion of the crank would throw the hand away from the handle, rather than violently twisting the wrist or breaking the thumb. Most Model T Fords had the choke operated by a wire emerging from the bottom of the radiator where it could be operated with the left hand. This was used to prime the engine while cranking the engine slowly; then the engine was started with a rapid pull of the crank handle. In good tune, an already-primed T engine only has to be cranked half a turn for it to successfully start.
The T's planetary transmission is famous for its differences from what later became the norm for car transmission operation. The 3 foot pedals are not used in the way later cars use their pedals. Operation is not difficult but requires "unlearning" habits used with later vehicles.
Design changes over the years
The following major changes were made (listed by year):
* 1909 — First model year - Water pump was discontinued; subsequent Model T engines used
thermosyphoning
Thermosiphon (or thermosyphon) is a method of passive heat exchange, based on natural convection, which circulates a fluid without the necessity of a mechanical pump. Thermosiphoning is used for circulation of liquids and volatile gases in heat ...
to circulate the coolant.
* 1911 —
Valve covers were added
* 1917 — Higher head with larger
water jacket
* 1919 —
Engine starter introduced as an option
* 1920 — Lighter-weight
rods and
piston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas- ...
s
* 1922 — The cylinder casting was changed so a single valve cover could be used
* 1926 — An extra boss was added at the rear for two additional bolts stiffening the transmission,
* 1927 — The
carburetor
A carburetor (also spelled carburettor) is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the venturi tube in the main meter ...
throttle rod was re-routed over the engine
Production run
The T engine was produced continuously from September 27, 1908, through August 4, 1941, exactly 12,000 days. This makes it one of the longest engines in series production, especially considering that the specifications remained mostly unchanged for this entire duration. Its production run for the U.S. consumer market for passenger cars and pickups was shorter, being the 19 years' production run of the Model T itself for that market (1908 to 1927). But the engine continued to be produced and sold to various consumer, industrial, military, and marine markets throughout the world until 1941.
Ford Model A engine
The engine used in the Model A was a
water-cooled L-head inline four with a displacement of .
This engine provided , but made substantially more torque, at of
torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of t ...
.
The
bore
Bore or Bores often refer to:
*Boredom
* Drill
Relating to holes
* Boring (manufacturing), a machining process that enlarges a hole
** Bore (engine), the diameter of a cylinder in a piston engine or a steam locomotive
** Bore (wind instruments), ...
and
stroke were also enlarged from the original Model T's engine; measuring x .
See also
*
List of Ford engines
*
Pietenpol Sky Scout
The Pietenpol Sky Scout is a parasol wing homebuilt aircraft designed by Bernard H. Pietenpol.
Development
The Sky Scout was a lower cost follow-on to the Pietenpol's first homebuilt design, the Pietenpol Air Camper. Using a lower cost Ford Mode ...
, a 1929-designed
homebuilt aircraft
Homebuilt aircraft, also known as amateur-built aircraft or kit planes, are constructed by persons for whom this is not a professional activity. These aircraft may be constructed from "scratch", from plans, or from assembly kits.Armstrong, Kenn ...
using a Model T engine
References
Bibliography
*
Further reading
*
*
*
{{DEFAULTSORT:Ford Model T Engine
Model T
The Ford Model T is an automobile that was produced by Ford Motor Company from October 1, 1908, to May 26, 1927. It is generally regarded as the first affordable automobile, which made car travel available to middle-class Americans. The relati ...
Products introduced in 1908
Gasoline engines by model
Straight-four engines