I-Rotary Apex Seal History
The development of the Iannetti designed Metallic I-Rotary Apex Seal began in late 1994.
The main goals of this project have been to develop a metallic apex seal which is the best “True and Tested” option for high boost, forced induction engines, and which achieves the same reputation of quality and performance as the ceramic Iannetti Apex Seal.
The I-Rotary Apex Seal has been designed and engineered to exhibit the following qualities:
The same sealing performance as the stock Mazda apex seal.
Demonstrate this high quality sealing performance while exposed to the extreme mechanical loads and temperatures experienced by an engine at high boost, especially at high RPM, like those used in drag racing, drifting, time attack and road racing.
Provide a toughness level and high resistance to fracture which allows this high performing apex seal to survive extreme uncontrolled events of detonation, pre-ignition or high temperature due to lean air fuel ratios commonly experienced by these high horsepower engines.
Achieve an excellent level of wear and gentleness to the rotor housing chrome surface.
From 1995 though 2001, a one piece design configuration was selected for the I-Rotary Apex Seal. This design approach was based on a suggestion by the late Jim Mederer of Racing Beat, who was using a custom 1-piece design metallic apex seal in the 3 rotor engines which propelled the Racing Beat Bonneville Land Speed Record car.
Custom 1-Piece Metallic Apex Seal Made by Mazda
The custom 1-piece metallic apex seal was a prototype piece made by Mazda Japan at the request of Mr. Mederer, specifically for this project.
It should be stated that in early 1995, Mr. Mederer stopped using the Mazda made custom metallic 1-piece design in favor of a similar 1-piece ceramic Iannetti Apex Seal. Throughout the rest of his career, he never went back to a metallic apex seal in any of his high performance engine projects.
The 1st Official Test of the I-Rotary Apex Seal
The first official test of the I-Rotary Apex Seal as a 1-piece design configuration was in the Summer of 1996. It was made from a custom metallic material which was selected from our an initial material research, which started in 1994. One of these I-Rotary Apex Seals can be seen in the image below.
1st Version of the I-Rotary Apex Seal
This first version of the I-Rotary Apex Seal was tested on a dynamometer by Carlos Lopez at CLR Motorsports. Miami, Florida, in a normally aspirated 13B peripheral race engine. The insight and assistance provided by CLR Motorsports during this test was very useful. Unfortunately, the results of the test were unsuccessful and many parts of the engine were severely damaged. The pursuit of a high hardness, high strength but brittle metallic material was discontinued.
The 2nd Official Test of the I-Rotary Apex Seal
Several new materials and designs were evaluated between 1996 and 1999. These research efforts concluded with a second test in the Spring of 1999. The I-Rotary Apex Seal used for this test was also a 1-piece design configuration using another custom metallic material
2nd Version of the I-Rotary Apex Seal
This test was performed by Dave Lemon at Mazdatrix, Signal Hill, California, USA using a turbo charged Mazda 3 rotor engine or a 20B. The engine ran well during its break-in period for the established number of hours. Unfortunately, during the initial power pull on the engine dynamometer, the metallic I-Rotary Apex Seal bent in the center and the engine lost compression.
Upon investigation, it was determined that the failure was caused by the thermal expansion compromise between the length of the 1-piece apex seal and the width of the rotor housing. Fortunately, there was no damage in this instance to any other part of the engine since the material used for this version of the I-Rotary Apex Seal was mechanically strong and tough as well as very gentle to the Mazda rotor housing chrome surface.
The 3rd Official Test of the I-Rotary Apex Seal
We continued our research from 2001 through 2004 with the evaluation of several experimental designs and materials for the I-Rotary Apex Seal. The 1-piece design metallic apex seal was no longer being considered because it is difficult to know the starting width of a particular rotor housing or the internal temperatures generated by a specific engine application.
In 2004, a new material and a new design was developed using a long section with two 45 degree ends to accept two corner end pieces.
3rd Version of the I-Rotary Apex Seal with 2 Corner Pieces
Similar to the material chosen in 1999, this version of the I-Rotary Apex Seal was made from a custom material which was very tough so that it could bend extensively without experiencing a catastrophic failure. It was also very gentle to the chrome surface of the Mazda rotor housing. The double corner apex seal design concept was chosen with the hope of improving the sealing performance of the I-Rotary Apex Seal.
This version of the I-Rotary Apex Seal was tested with and without a nitrided surface as well as with other coatings. The nitrided surfaces were made using various processes such as the Ion Pulse and Batch Nitriding methods to determine if there were any differences between these processes on the performance of the I-Rotary Apex Seal.
No difference in performance between any of these surface treatment processes was noted.
The double corner I-Rotary Apex Seal was tested in various drag racing cars with mixed results. One of these tests was performed under the guidance of Sr. Umberto Vivo, Mecanica Vivo in Puerto Rico, circa 2006 using a normally aspirated drag racing engine with gasoline as fuel plus over 200 HP of nitrous oxide. The results from these tests were successful in the application even though the car was experiencing severe overheating during each of the two dozen or more passes down the drag strip.
Unfortunately, this double corner I-Rotary Apex Seal design concept did not prove to exhibit the desired performance when exposed to the high horsepower levels generated by high boost turbocharged drag race engines. The development and testing of this double corner design concept for the I-Rotary Apex Seal was subsequently stopped.
From 2006 through 2014
Several new materials and design concepts were evaluated during the period between 2006 and 2013.
Some of the materials and design concepts with promise during laboratory experiments were tested by Mr. Jose Le Duc, El Duke Racing in New Jersey, USA in a high boost drag racing engine. These tests again provided mixed and inconclusive results even though the assistance that El Duke gave us was invaluable and greatly appreciated.
From 2013 to 2016
It was clear from these disappointments and the capital investment made on this project that a different research strategy had to be developed if our goals established in 1994 for the I-Rotary Metallic Apex Seal were to be achieved.
The directors of I-Rotary decided to make a major commitment of time and resources to develop a testing simulation strategy which more accurately represented the engine requirements of a high boost race engine without the need of an actual engine test. Several hundred new materials and designs were evaluated using the new testing strategy. Also, many of the old materials and designs were retested.
From 2016 to 2018
These research efforts culminated in 2018 with the successful engine testing of the Prototype and Patent Pending I-Rotary Apex Seals in all types of high performance environments such as high boost drag racing cars, drifting race cars and road or circuit race cars*.
The I-Rotary Apex Seal
The I-Rotary Apex Seal above has achieved the goals established in 1994:
The same sealing performance as the stock Mazda apex seal. This means that a Mazda rotary engine can obtain the highest compression level attainable when using a metallic apex seal.
Maintain this high quality sealing performance when exposed to the extreme mechanical loads and temperatures experienced by an engine at high boost, like those found in a high horsepower drag racing engine.
Exhibit a toughness level which allows the I-Rotary Apex Seal to survive extreme uncontrolled events of detonation, pre-ignition or high temperature due to a lean air-fuel ratio commonly experienced by these high horsepower engines.
Attain an excellent level of low friction and wear while being gentle to the rotor housing chrome surface. And finally,
Exhibits dimensions consistency from set to set as established by the ceramic Iannetti Apex Seal over the past 3 decades.
The patent pending I-Rotary Apex Seal has been engineered to be the highest performing and most consistent aftermarket metal apex seal available for the Rotary Engine.
* Special thanks to Richard Green, Chris Green and Green Brothers Racing in New Zealand and their clients Abbot Racing and Ryan Dorricott, Jose Le Duc of El Duke Racing, Paul Thomas of MazMart, Bill Schoots of WPS Racing in Australia, Carlos Lopez of CLR Motorsports, Dave Lemon of Mazdatrix and Sr. Umberto Vivo of Mecanica Vivo for their trust, support and testing of the I-Rotary Apex Seal.
We are also very grateful for the assistance provided in the development of the this product by Rick Engman of Mazmart and the late Jim Mederer of Racing Beat.