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Engineering Team

XRDi has a combined experience of over 120 years in the field of engine research, design and development.  This includes the design, manufacture, development and testing of engines, both two and four-stroke, from 1.5 HP to more than 1000 HP for marine, industrial/commercial, military and high performance/racing applications.


Andy Allen – Founder – Chief Technology Officer


Andy is responsible for leading XRDi in engine and drive system research and development while searching out new technologies to develop, license, or acquire. After graduating from Georgia Tech as a Mechanical Engineer, his career began with Pratt & Whitney Aircraft and evolved over the next 35 years to include aircraft, racing, industrial, marine propulsion systems, engine design and multiple fuel combustion technology.   Andy developed the patented multi-fuel preparation & delivery device currently deployed in the U.S. Marine Corp M17 Decontamination Units.  Andy accumulated a wealth of engineering knowledge along with prestigious affiliations with some of the world’s most recognized experts in the field of engine design. Andy holds four engineering patents and has served as chairman of the Society of Automotive Engineer’s Small Powerplant Committee. 


Professional Affiliations:




Past Chairman of the SAE Small Powerplant Committee

Technical Committee Co-Chairman for the 1997 Off-Highway Conference

Small Powerplant Committee member since 1990




6293232 Multi-Fuel Engine

6401674 Multi-Fuel Engine

4926809 Internal combustion engine with rotary valve

4617884 Torsional vibration isolator and method

3999482 Method and apparatus for processing and harvesting trees

James T. Nealon

Jim provides technical leadership, knowledge and services as Engineering Manager.  He has committed his career to electronic engineering that includes design, development and manufacturing and testing.  Jim has a strong technical background in computer hardware design and experience in electronic and mechanical design.  Jim is an expert in engine management and automotive electronic control systems with proven competence in managing projects to completion. 

B.S. Mathematics - Ursinus College, Collegeville, PA
Electrical Engineering - Lycoming College, Williamsport, PA

Dan Marcellis: Director of Engineering, responsible for leading the engineering team in the development of the multi-fuel family of engines. Mr. Marcellis formerly served as Director of Mercury Outboard Racing for Mercury Marine. Dan has a B.S. in Mechancial Engineering from Michigan Tech.

Mike Wienandt: Manager, Modeling/Simulation/Performance. Mr. Wienandt formerly worked for over 20 years at Mercury Marine as Project Design Lead, supporting Mercury’s outboard racing efforts. His racing team also holds several national championships in outboard engine and snowmobile racing.

Brian Books: Design Engineer. Mr. Books supports the Chief Technology Officer in the design and modeling (CAD/Pro E) of the family of engines. He obtained his Associates Degree from Waukesha College.

Technical Consultants

Steve Bethel: Mr. Bethel, through his company Leadfoot Engineering, has worked with XRDi for 9 years, leading its piston development efforts. His involvement has now increased in focus to include all aspects of engineering activity. Mr. Bethel formerly served as Director of Advanced Product Engineering at Mercury Marine. He received his B.S. and M.S. Degrees in Mechanical Engineering from Michigan Technological University.

Britt Cobb, PhD: Dr. Cobb, through his consulting company, Cobb Engineering, serves as a full time Engineering Technical Consultant to the Team with an emphasis on combustion and vibration. Dr. Cobb is a recognized industry expert in propulsion development, gas dynamics and vibration, having consulted for many years for recognized leaders in propulsion products. Dr. Cobb obtained his M.S. and PhD in Mechanical Engineering from the University of Florida.

Z. “Zigi” Polch, PHD: Principal Mechanical CAE Engineer. Dr. Polch leads the structural and mechanical FEA and thermal simulation efforts for the Team. He obtained both his MS in Applied Mathematics and his PhD in Fluid Mechanics from Warsaw Polytechnic.

Tom Braxton: Mr. Braxton supports the Team as a Mechanical Design Engineer and specializes in Pro E modeling, transition to casting and FEA support. He graduated from Florida College of Engineering with a B.S. in Mechanical Engineering.



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