Technical Articles and Product Descriptions

Reference Materials

Additional Products

Race Engine Technology

07/09/08

1. Updated the Race Engine Technology Current Issue page to describe Volume 31, available 07/05/08.
2. Added several new entries to the Engines and Turbomachinery section of the Reference Library.
3. Added 3500 watt Honda Generator to Stuff For Sale.

06/12/08

• Updated the Race Engine Technology (RET) Special Reports page to describe the content of the new special report in Formula One Technology.

05/29/08

1. Expanded the description of the Engineering Services available from EPI, Inc.
2. Updated the Race Engine Technology (RET) Magazine page to describe the content of the current RET Issue (030) and extend the discount subscription offer

05/15/08

1. Added the comparison of NASCAR CUP V8 engines vs. F1 V8 engines to the engine technology section.
2. Added new pages describing the content details of Race Engine Technology Past Issues, and the Race Engine Technology Special Reports on CUP, 24-Hour and F1 race technology.
3. Added new information to PSRU Technology pages: Introduction, Implementations, PSRU Torsional Vibration.
4. Added new information about Aircraft Engine Conversions to the Evaluating a Conversion page.

03/31/08

1. Complete remake of the site: new site format, presentation, and look.
2. Broke PSRU Products and PSRU Technology into separate sections, and expanded the PRSU Products section to include our other transmissions with the Propeller Reduction Units.
3. Broke Engine Technology and Aircraft Engine Products into separate sections.
4. Updated several of the Mechanical Basics and Engine Technology pages.

03/18/08

• Added DISCOUNT SUBSCRIPTION OFFER for the World's Premier Engine Technology Magazine:
  RACE ENGINE TECHNOLOGY.

01/14/08

1. Updated the Mark-15 Gearbox pages to show the improved housing design and the fact that the governor drive subsystem has been revised in order to move the governor mounting-face nearly an inch inboard in order to eliminate potential cowling interferences with replica fighter aircraft such as the PAPA-51 Mustang and the FEW Mustang. 
2. Updated the 3-view drawings and 3D downloadable model to reflect the changes described above.

01/08/08

1. Expanded the discussion of planetary reduction units in PSRU Section..
2. Cosmetic changes and link updates.

11/06/07

1. Removed the bargain RotorWay Helicopter for sale.
2. Expanded the treatment of the Hy-Vo Chain PSRU section to better address some of the misleading claims made about those units.
3. Expanded the description of Propeller Strike Damage to include information from AD-2004-10-14.

09/23/07

• Added a description and photos of a bargain RotorWay Helicopter for sale

08/21/07

• Added new data regarding RotorWay Autorotation Clutch Failures.

08/20/07

1. Reorganized and expanded the section on RotorWay Secondary Failures.
2. Added a page describing, in detail, the operation of the RotorWay Autorotation Clutch.
3. Added a page describing current problems with the EPI Secondary Upgrade.
4. Removed the pages describing the EPI Secondary Upgrade product.
5. Removed the pages describing the EPI Turbine Conversion for the RotorWay Helicopter.

06/12/07

1. Published updated Installation Drawings of the Mark 15 gearbox product.
2. Published updated information on the EPI Gen-2 V8 engine.

03/28/07

• Expanded the Propeller Performance page, and corrected a math error on that page.

03/07/07

• Updated the STUFF FOR SALE section to show all items have been sold.

02/26/07

• Published new Installation Drawings for the Mark-15 gearbox as well as an updated downloadable 3D-CAD file of the Mark-15.

02/08/07

• Posted BRAND NEW 505-HP GM  LS-7 ENGINE FOR SALE.

02/03/07

• Added new information to the Converting Certified Aircraft page.

01/28/07

• Since the last "official" update (08/29/06) there have been several small updates to improve and clarify various presentations here. This revision reorganizes and updates the ENGINES & TECHNOLOGY section of the site. Further updates to that section, scheduled for later this year, will include the material which EPI's CEO presented at the 2006 Advanced Engine Technology Conference (AETC)

08/29/06

• Added new information to the Converting Certified Aircraft page and a new section describing various new and used Parts and Products For Sale.

07/27/06

• Added new information and a new page to the Aircraft Engine Conversions section.

07/07/06

• Updated RotorWay Turbine Conversion Information.

06/15/06

1. Added FEA results for critical Mark-15 Propeller Reduction Gearbox components.
2. Updated Piston Velocity & Acceleration page in the Engine Technology section.

05/24/06

• Added new information on the Mark-15 Propeller Reduction Gearbox.

05/02/06

1. Lowered website price of RotorWay Billet Rocker Covers.
2. Added progress information on RotorWay Turbine Conversion ("Mark-17").
3. Added new information on the Mark-15 Propeller Reduction Gearbox.

04/17/06

• Added new information to the section on Evaluating an Aircraft Engine Conversions.

03/24/06

• Substantial revisions and improvements to the PSRU Technology Section, including a PSRU FAQ's page and an improved Technology Summary page.

03/18/06

• Minor corrections to the Mark-15 Propeller Gearbox information; Added three new views with various sizes of spinners to the Mark-15 Gearbox Dimensions page.

03/09/06

1. Added new information, pictures and dimensions of the Mark-15 Propeller Gearbox; Added new information on EPI LS-based and Big-Block-based engines.

01/30/06

• Clarified and expanded several pages in the Engine Technology section and the Engine Conversion section.

01/14/06

• Added five new pages with new information on the Turbine Conversion for the RotorWay Helicopter, including pictures and more details on the Power Unit, Main Rotor Drive, Tailrotor Drive, Fuel System and Control System.

01/04/06

1. Reorganized the ROTORWAY HELICOPTER PRODUCTS section, with new information.
2. Added new information on the Turbine Conversion for the RotorWay Helicopter.
3. Added new information in the Aircraft Engine Conversion section, explaining how to decide whether a proposed engine swap is rally a good idea.

12/15/05

1. Complete revision of the Aircraft Engine Conversion section with a new page describing the new "21st Century Cropduster".
2. New information on the redesigned EPI Mark-15 Propeller Reduction Gearbox.
3. New section on Propeller Performance and how to make a good selection of a propeller for your aircraft.
4. New section explaining the effects of Torsional Excitation on a propeller reduction gearbox.

12/12/05

• Revised Rotorway Secondary Upgrade pages for clarity, brevity, and price decreases.

09/14/05

• Announced the NEW, Finned Billet-Aluminum Rocker Covers for the Rotorway Engine.

08/23/05

• Reorganized and clarified the entire RotorWay Secondary Drive section; added information on the EPI Secondary System Test Flight Program; Expanded several technical discussions in the EPI Secondary Upgrade section. 

07/09/05

1. Updated several technical discussions in the EPI Secondary Upgrade section of the RotorWay Secondary Drive section.
2. Updated RotorWay Secondary Known Failure Database

12/27/04

• Updated technical information on all EPI Gearboxes and added LS-engine power and torque curves in the Mark-15 Gearbox page.

10/25/04

1. Added a SEARCH capability to enable visitors to find information more easily.
2. Added 4 new pages and updated several other pages in the RotorWay Secondary Drive section to include the data shown in EPI's technical presentation at Homer's-2004, including a detailed explanation of the Higher Shaft Load from the ProDrive Belt System, a Comparison of the EPI and ProDrive Secondary Shaft, and a page covering seven important Gates Belt Issues.
3. Added lots of new details, options, and pricing information on the EPI Secondary Upgrade program, plus 6 new pages presenting: (a)  Details of our Shaft Material, (b)  Hardness of Our Clutch Surface, (c)  Shaft Toughness,   (d)  Why Stress Matters, (e)  Upper Bearing Details,  and (f) Pictures of the EPI Secondary Upgrade.
4. Added lots of new material to the page which covers the detailed analysis of the ProDrive belt System.
5. Added a new page to rebut the Errors published on the ProDrive website after our technical presentation at Homer's-2004.
6. Added a new page ( Properties of Belt Drives ) to the Mechanical Basics section and added new material to Stress and Strain and Metal Fatigue.
7. Added lots of new information on the T-62 Turbine Conversion for the Rotorway helicopter.
8. Added new information and pictures of the Phase-1 EPI  500-HP Aircraft V8 Engine.

05/24/04

1. Added the EPI Reference Library and reference notations throughout the site.
2. New Mechanical Basics sections on Velocity and Acceleration, Force and Friction, Stress and Strain, Metal Fatigue, Fretting Corrosion and Bearing Life.
3. Additions to the PSRU section, including expanded presentations of Gear Information and Hy-Vo Chain Information, as well as pictures of the innards of the Mark-14 gearbox, two new propeller gearbox designs: the Mark-15 and Mark-16, and a new helicopter gearbox for swapping a turbine engine into a RotorWay 162.
4. The analysis of the RotorWay Secondary Shaft failure problems has been substantially upgraded, with new pages, new analysis, new FEA with pictures, and major rewrites of previous pages. It includes a new presentation of the increased loading generated by the ProDrive™ toothbelt system, expanded analysis showing the V-belt, Factory Chain Drive, and ProDrive™ at the same Max Power and Cruise Power conditions, Bearing Failure Analysis, PLUS announcement and description of a new, economic solution to the RotorWay Secondary Shaft failure problems and removed reference to the previous design which included a clutch.

07/21/03

• Added data on a NEW 35mm secondary failure (July 15, 2003) to the RotorWay Secondary Failure Database.

06/19/03

• Minor wording revisions to several pages in the RotorWay section; also fixed numerous typos and removed incorrect price for a drive belt.

06/16/03

• Technical and editorial revisions to add clarity to the presentation of the RotorWay drive failure problems.

06/15/03

• Added an in-depth analysis of the alarming failure rate of the secondary drive system on the RotorWay Exec series of helicopters.

06/10/03

• Complete reorganization of site. Added a comprehensive Site Map and new material on ENGINE TECHNOLOGY and the new Mark-14 PSRU.

06/24/02

• Added a new Main-Button category (SERVICE BULLETINS) and published all EPI service bulletins.

05/23/02

• Changed organization of PSRU PRODUCTS page in order to make THE STORY BEHIND THE MARK-9 PSRU easier to find.

04/09/02

• Added new page on THE STORY BEHIND THE MARK-9 PSRU; Added specifications of new PSRU PRODUCTS; Revised and reworded many of the technology pages.

03/15/02

• Added new pages (PROPELLER DAMAGE) on prop strikes; Added direct link button (left side of page) to the PROPELLER DAMAGE page.

11/20/01

• Added "Next Subject" links to all PSRU TECHNOLOGY pages; Revised direct link buttons on left side of pages.

11/15/01

1. Significant revisions to the PSRU OVERVIEW page to expand coverage of Link Chain Drives and announce a new EPI PSRU product;
2. Addition of CHAIN DRIVE DESIGN ISSUES page.

09/03/01

1. Added NEAT LINKS page.
2. Added page which explains the relationship between POWER and TORQUE.

09/01/01

1. Added REVISION HISTORY page; Expanded COMPANY BACKGROUND page; Compressed CEO RESUME and moved it to separate page under COMPANY BACKGROUND.
2. Rewrote introduction to AIRCRAFT V8 DEVELOPMENT section, with new pages on TORSIONAL ABSORBERS and THE FUTURE OF 100-LL FUEL.
3. Replaced entire PSRU TECHNOLOGY section with expanded presentations of VIBRATION FUNDAMENTALS, TORSIONAL EXCITATION, TRANSMISSIBILITY, and COMPONENT LOADS.
4. Expanded AIRCRAFT ENGINE CONVERSIONS section, with new pages on ENGINE INSTALLATION ISSUES, ENGINE MOUNT DESIGN and WHIRL MODE.