From: EPI Inc.       Contact: tech@epi-eng.com

 

  Race Engine Technology Magazine CURRENT ISSUE of Race Engine Technology Magazine

Race Engine Technology Magazine

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- Piston Engine Technology -

Articles Describing Technical Aspects of Engine Design and Operation

In early 1993, EPI began the development of a lightweight, 500 HP, liquid-cooled V8 aircraft powerplant (engine, PSRU, and accessory drives) for a high-performance, two-place tandem aircraft which EPI's CEO had designed. Since then, EPI has developed that powerplant (the Gen-1), then using newer hardware technology and refined design concepts, developed the EPI Gen-2 powerplant, and now is developing a clean-sheet 60-degree V12 engine and a CI-V8 engine designed for Jet-A fuel. Several standalone products have resulted from those programs, including PSRU's, ignition systems, lubrication systems, accessory drives, and engine mount structures.

The analysis methodology used in the development of these powerplants has been the subject of two technical presentations given by EPI's CEO at the Advanced Engine Technology Conference  (AETC, 1996 and 2006). This section of the website expands on those presentations in order to make the basics of engine design, development and evaluation available to a wider audience.

Several of the articles in this section, designated by "{RET}" next to the title, have been published in Race Engine Technology Magazine, a periodical which is valued at the highest levels of motorsport, and portions have been published in CONTACT magazine, and in EAA's on-line magazine EXPERIMENTER.

The details about the EPI Gen-1 engine, the EPI Gen-2 aircraft powerplant and a new engine EPI is developing, can be seen in the Aircraft Engine Products section of this website.

Table of Contents

 1. Power and Torque The difference between power and torque; how power depends on torque and RPM.    IT IS ESSENTIAL TO UNDERSTAND THIS SUBJECT

 2. Converting Fuel into Horsepower How engines convert fuel energy into mechanical energy, the limitations of that conversion, and a yardstick (BSFC) to evaluate the claims of engine builders.

 3. Volumetric Efficiency The efficiency of an engine's air-pumping capability, and how mass airflow is the critical determinant of engine performance.

 4. Brake Mean Effective Pressure (BMEP) A basic yardstick of engine performance, and how to use it to reality-check horsepower claims.

 5. Engine Comparison Tools A summary of the engine evaluation tools covered in the preceding sections, PLUS a new tool (EPC) for comparing the performance of diverse engines.

 6. Piston Motion, Velocity and Acceleration The basic motion of a piston in its cylinder, providing the basis for understanding subsequent subjects.

 7. Crankshaft Design, Materials and Manufacturing {RET} Crankshaft structural and vibratory loads, design issues, metallurgy, manufacturing, and heat treatment processes.

 8. Forces on Reciprocating Components  (UNDER CONSTRUCTION) The forces that are generated within an engine during key portions of the intake-compression-combustion-exhaust cycles.

 9. Camshaft and Valvetrain Fundamentals The basics of valve operation, describing cams and the associated valve-moving componentry.

10. Valvetrain Velocity and Acceleration   (UNDER CONSTRUCTION) The forces, accelerations and vibrations which are common in high performance engine valvetrains.

11. Port Flow and Combustion Chambers  (UNDER CONSTRUCTION) The basics of achieving and verifying high levels of flow while maintaining high flow quality.

12. Engine Bearing Fundamentals {RET} The fundamental operating modes and characteristics of fluid film bearings, which comprise the vast majority of bearings used in 4-stroke piston engines and certain 2-stroke applications.

13. Engine Materials {RET} Details on some new alloys which are evolving into key engine materials, as well as details on the properties and chemistries of certain popular alloys.

14. Lubrication Systems                (UNDER CONSTRUCTION)   Engine lubrication systems and requirements, components, oil pumps and oil pump hype.

15. Cooling and Heat Rejection     (UNDER CONSTRUCTION)   Cooling problems faced by a high-power engine operating continuously at a high percentage of max output.

16. Turbochargers: Technology and Developments {RET} Technical details on the operation of turbocharger systems and an insight into current developments (2008) in the technology.

17. Exhaust System Technology {RET} The operation of finite pressure waves in an exhaust system, and how they can be used to increase power; also, advanced exhaust materials and exhaust system implementations.

18. The Torsional Output of Piston Engines The origins and severity of the torque spikes which occur every time a cylinder fires.

19. Crankshaft Torsional Absorbers The purpose and operation of the torsional absorbers (misnamed "dampers") on the free end of an engine crankshaft.

20. Reversing the Rotation of an Engine Issues which need to be addressed when the direction of crankshaft rotation of an engine is changed.

21. Electronic Engine Controls Issues arising from adaptating contemporary engine control computers to aircraft operation and attaining an acceptable degree of reliability.

22. A Comparison of two Ultimate Engines {RET} A comparison of the World's Definitive V8 Engines (NASCAR Cup and Formula-One) using several important and revealing metrics.

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