The Graflight V-8 is an

aircraft diesel engine An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines ...

developed by Wisconsin-based Engineered Propulsion Systems

Design

The Graflight V-8 is a liquid-cooled, flat V-8 with steel pistons and

compacted graphite iron Compacted graphite iron (CGI), also known as vermicular graphite iron (GJV, VG, JV or GGV from the german: "Gusseisen mit Vermiculargraphit") especially in non-English speaking countries, is a metal which is gaining popularity in applications that ...

crankcase for better strength and durability than

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It h ...

at similar weight, increasing

time between overhaul Time between overhauls (abbreviated as TBO or TBOH) is the manufacturer's recommended number of running hours or calendar time before an aircraft engine or other component requires overhaul. On rotorcraft, many components have recommended or ...

s to 3,000 hours. It is managed by a

Bosch Bosch may refer to: People * Bosch (surname) * Hieronymus Bosch (c. 1450 – 1516), painter * Van den Bosch, a Dutch toponymic surname * Carl Bosch, a German chemical engineer and nephew of Robert Bosch * Robert Bosch, founder of Robert Bosch Gm ...

ECU and can run on Jet A,

JP-8 JP-8, or JP8 (for "Jet Propellant 8") is a jet fuel, specified and used widely by the US military. It is specified by MIL-DTL-83133 and British Defence Standard 91-87, and similar to commercial aviation's Jet A-1, but with the addition of corrosi ...

or straight

diesel fuel Diesel fuel , also called diesel oil, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place without a spark as a result of compression of the inlet air and ...

. It is intended to be used in

general aviation General aviation (GA) is defined by the International Civil Aviation Organization (ICAO) as all civil aviation aircraft operations with the exception of commercial air transport or aerial work, which is defined as specialized aviation service ...

airplanes, small

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attribut ...

military drone An unmanned combat aerial vehicle (UCAV), also known as a combat drone, colloquially shortened as drone or battlefield UAV, is an unmanned aerial vehicle (UAV) that is used for intelligence, surveillance, target acquisition, and reconnaissance ...

s, small boats or troop carriers. The engine is specifically targeting the

Robinson R44 The Robinson R44 is a four-seat light helicopter produced by Robinson Helicopter Company since 1992. Based on the company's two-seat Robinson R22, the R44 features hydraulically assisted flight controls. It was first flown on 31 March 1990 an ...

Beech Bonanza The Beechcraft Bonanza is an American general aviation aircraft introduced in 1947 by Beech Aircraft Corporation of Wichita, Kansas. The six-seater, single-engined aircraft is still being produced by Beechcraft and has been in continuous prod ...

GippsAero GA8 Airvan The Mahindra Airvan 8 (formerly the GippsAero GA8 Airvan 8) is a single-engined utility aircraft manufactured by GippsAero (formerly named Gippsland Aeronautics) of Victoria, Australia. It can seat up to eight people, including the pilot. Th ...

Cessna TTx The Cessna 400, marketed as the Cessna TTx, is a single-engine, fixed-gear, low-wing general aviation aircraft built from composite materials by Cessna Aircraft. The Cessna 400 was originally built by Columbia Aircraft as the Columbia 400 un ...

and

Cessna 206 The Cessna 205, 206, and 207, known primarily as the Stationair (and marketed variously as the Super Skywagon, Skywagon and Super Skylane) are a family of single-engined, general aviation aircraft with fixed landing gear, used in commercial air ...

as possible applications. The design is a , 4.3-liter engine with steel pistons,

connecting rod A connecting rod, also called a 'con rod', is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the cranksha ...

s, and crankcase to improve reliability. At , it weighs more than a conventional

aircraft engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years ma ...

, not including the

radiator Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in cars, buildings, and electronics. A radiator is always a ...

for cooling. It should be 30-40% more expensive to purchase than a comparable

avgas Avgas (aviation gasoline, also known as aviation spirit in the UK) is an aviation fuel used in aircraft with spark-ignited internal combustion engines. ''Avgas'' is distinguished from conventional gasoline (petrol) used in motor vehicles, w ...

engine, but with 30-50% better fuel economy. Its low vibration levels allow the use of composite or aluminum

propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...

s. The engine's 17:1

compression ratio The compression ratio is the ratio between the volume of the cylinder and combustion chamber in an internal combustion engine at their maximum and minimum values. A fundamental specification for such engines, it is measured two ways: the stat ...

gives it a best

brake specific fuel consumption Brake-specific fuel consumption (BSFC) is a measure of the fuel efficiency of any prime mover that burns fuel and produces rotational, or shaft power. It is typically used for comparing the efficiency of internal combustion engines with a shaft ou ...

of less than , compared to typical avgas engines with . It is expected that the Graflight V-8 will burn under of fuel at 65% power. As a direct comparison, the version of the Graflight V-8 engine will weigh more than the comparable

Lycoming TIO-540 The Lycoming O-540 is a family of air-cooled six-cylinder, horizontally opposed fixed-wing aircraft and helicopter engines of displacement, manufactured by Lycoming Engines. The engine is a six-cylinder version of the four-cylinder Lycoming O-3 ...

-AE2A ( dry) or

Continental TSIO-550 The Continental IO-550 engine is a large family of 9 liter fuel injected six-cylinder, horizontally opposed, air-cooled aircraft engines that were developed for use in light aircraft by Teledyne Continental Motors. The first IO-550 was deliver ...

-E ( dry). It will cost 30% more, but with a higher time between overhaul and lower fuel burn, it will have lower

operating costs Operating costs or operational costs, are the expenses which are related to the operation of a business, or to the operation of a device, component, piece of equipment or facility. They are the cost of resources used by an organization just to main ...

. At normal 75% cruise power, the Graflight V-8 consumes of fuel, whereas the Continental TSIO-550-E burns , a reduction of 30%.

Development

EPS set out to

certify Certification is the provision by an independent body of written assurance (a certificate) that the product, service or system in question meets specific requirements. It is the formal attestation or confirmation of certain characteristics of a ...

a new-design flat 8 engine, to replace existing general aviation gasoline engines, with the aim of reducing fuel costs by 45%. EPS started work on the design in 2006, a process that took five years. The engine was first flown in May 2014, first exhibited at the 2017

EAA AirVenture EAA AirVenture Oshkosh (formerly the EAA Annual Convention and Fly-In), or just Oshkosh, is an annual air show and gathering of aviation enthusiasts held each summer at Wittman Regional Airport and adjacent Pioneer Airport in Oshkosh, Wisconsin, ...

and

FAA The Federal Aviation Administration (FAA) is the largest transportation agency of the U.S. government and regulates all aspects of civil aviation in the country as well as over surrounding international waters. Its powers include air traffic m ...

certification was expected at that time by the end of the year. Later in 2017 the testing progress was delayed by insufficient funding. By July 2018 it had completed 25 hours of flight testing on a

Cirrus Aircraft The Cirrus Design Corporation, doing business as Cirrus Aircraft (formally Cirrus Design), is an aircraft manufacturer that was founded in 1984 by Alan and Dale Klapmeier to produce the VK-30 kit aircraft. The company is owned by a subsidiar ...

airplane. At that point the company hoped to attract

Fortune 500 The ''Fortune'' 500 is an annual list compiled and published by '' Fortune'' magazine that ranks 500 of the largest United States corporations by total revenue for their respective fiscal years. The list includes publicly held companies, along ...

investors and planned that a new demonstrator should be ready in the first quarter of 2019. The production version of the engine was shown at

AERO Friedrichshafen AERO Friedrichshafen is a trade show dedicated to European general aviation. It is held yearly in April on the shores of Lake Constance Lake Constance (german: Bodensee, ) refers to three Body of water, bodies of water on the Rhine at the ...

in April 2019 and work continued on environmental and block testing towards the goal of type certification. Unable to obtain the needed financing to continue operations, the company filed for

Chapter 11 bankruptcy Chapter 11 of the United States Bankruptcy Code ( Title 11 of the United States Code) permits reorganization under the bankruptcy laws of the United States. Such reorganization, known as Chapter 11 bankruptcy, is available to every business, whet ...

protection in August 2020.

Applications

Cirrus SR22 The Cirrus SR22 is a single-engine four- or five-seat composite aircraft built from 2001 by Cirrus Aircraft of Duluth, Minnesota. It is a development of the Cirrus SR20, with a larger wing, higher fuel capacity, and a more powerful, 310-hors ...

Design

Development

Applications

Specifications (Graflight V-8)

References

External links