Research Staff


Tim Theiss
Group Leader, Fuels and Engines Research Group
(T) 865-946-1348
(F) 865-946-1354

Professional Highlights

M.S., Engineering Mechanics; Virginia Tech.

Mr. Theiss has been on the staff at ORNL since 1987, as a research development staff member, a program manager and group leader.  He has over 15 years of experience in program development and program management at ORNL in various technical areas, mostly related to power systems and reciprocating engine-based power generation.  Most recently, Tim’s work has involved liquid and gaseous alternative fuels, including biofuels for transportation and stationary power applications.  Since 2008, Tim has lead ORNL’s Fuels & Engines Research Group, one of the larger comprehensive internal combustion engine research and development groups in the DOE system.  Tim has been very active in the ORNL intermediate ethanol blend effort for the past few years interacting with DOE’ Office of the Biomass Program and Office of Vehicle Technology, as well as other stakeholders.  Since October 2011, Tim has been serving as the Interim Laboratory Relationship Manager for the DOE Office of the Biomass Program.


Technical Highlights October 2015Oct 2015 highlights

Journal Paper to Report the Oak Ridge National Laboratory’s (ORNLs) Recent Discovery of Incompatibility between Diamond-Like Carbon (DLC) and Zinc Dithiophosphate (ZDDP)...