Exhaust pulse pressure charging (EPPC) is a system for supercharging

Supercharger

A supercharger is an air compressor used for forced induction of an internal combustion engine.The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally aspirated engine, which allows more fuel to be burned and more work to be done per cycle,...

 two-stroke

Two-stroke cycle

A two-stroke engine is an internal combustion engine that completes the process cycle in one revolution of the crankshaft...

 diesel engine

Diesel engine

A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

s of the loop-scavenge type. Loop-scavenge engines cannot be pressure-charged in the same way as uniflow engines or four-stroke

Four-stroke cycle

A four-stroke engine, also known as four-cycle, is an internal combustion engine in which the piston completes four separate strokes—intake, compression, power, and exhaust—during two separate revolutions of the engine's crankshaft, and one single thermodynamic cycle.There are two...

 engines because the inlet and exhaust ports are open at the same time.

Overview

The engine usually has a Roots blower to provide air for scavenging and this is arranged to deliver excess air so that air follows the exhaust gases into the exhaust manifold. Some of this air is then forced back into the cylinder by a rise in pressure in the exhaust manifold resulting from the exhaust pulse from another cylinder.

For additional pressure charging a turbocharger

Turbocharger

A turbocharger, or turbo , from the Greek "τύρβη" is a centrifugal compressor powered by a turbine that is driven by an engine's exhaust gases. Its benefit lies with the compressor increasing the mass of air entering the engine , thereby resulting in greater performance...

 may be fitted, in series with the Roots blower, but a turbocharger cannot be used alone because it would not provide enough air for scavenging at low speeds.

Examples

Exhaust pulse pressure charging was used by Crossley

Crossley

Crossley, based in Manchester, United Kingdom, was a pioneering company in the production of internal combustion engines. Since 1988 it has been part of the Rolls-Royce Power Engineering group.More than 100,000 Crossley oil and gas engines have been built....

 in these diesel locomotive

Diesel locomotive

A diesel locomotive is a type of railroad locomotive in which the prime mover is a diesel engine, a reciprocating engine operating on the Diesel cycle as invented by Dr. Rudolf Diesel...

 engines:

• the HST-Vee 8, used in the British Rail Class 28
  British Rail Class 28
  The British Rail Class 28 diesel locomotives, or 'Metrovicks' as they were popularly known, were built as part of the British Railways 1955 Modernisation Plan. The locomotives had a Co-Bo wheel arrangement – unique in British Railways practice though not uncommon in other countries, notably Japan...
  
  , the CIE 001 Class
  CIE 001 Class
  The Córas Iompair Éireann 001 Class locomotive was manufactured by Metropolitan-Vickers at their Dukinfield Works in Manchester.The 001 Class locomotive was the backbone of mainline passenger and freight train services on the Irish railway network for forty years from 1955 until the mid-1990s when...
  
   and the WAGR X class
  WAGR X class
  The WAGR X class was a class of 48 diesel electric locomotives built for Western Australian Government Railways by Beyer Peacock and Metropolitan Vickers, at Bowesfield Works, Stockton-on-Tees between 1954 and 1956.-The Crossley engine:...
  
  
• the EST-Vee 8 used in the CIE 201 Class
  CIE 201 Class
  The Córas Iompair Éireann 201 Class was a class of 34 diesel electric locomotives manufactured by Metropolitan-Vickers at their Dukinfield Works in Manchester. They were a smaller, lighter and less powerful version of the 001 Class and were originally intended for branch line passenger and freight...
  
  
• the ESNT 6 used in British Rail Class D3/3
  British Rail Class D3/3
  British Rail Class D3/3 was a 0-6-0 shunting locomotive built by British Rail at their Derby Works in England. It was similar to the British Rail Class 08, except they were built with different engines and traction motors. They were all withdrawn and scrapped after only twelve years of...
  
   shunting locomotives

See also

• Backpressure
• Inertial supercharging effect
  Inertial supercharging effect
  Inertial supercharging effect is the result of incoming fuel/air charge developing momentum greater than intake stroke would generate alone. It is achieved by a combination of head/port configuration, and cam profile/valve timing....
  
  
• Kadenacy effect
  Kadenacy effect
  The Kadenacy effect is an effect of pressure-waves in gases. It is named after Michel Kadenacy who obtained a French patent for an engine utilizing the effect in 1933. There are also European and US patents...
  
  
• Pressure wave supercharger
  Pressure wave supercharger
  A pressure wave supercharger is a type of supercharger technology that harnesses the pressure waves produced by an internal combustion engine exhaust gas pulses to compress the intake air. Its automotive use is not widespread; the most widely used example is the Comprex, developed by Brown Boveri...
  
  

Sources

• The Diesel Locomotive by R. L. Aston, published by Thames and Hudson, London, 1957, pp 19, 22-24, 31