The design of a new multi-cylinder gasoline research engine with a high degree of flexibility in the way it can be configured to test advanced charging systems, variable valve trains and air hybrid layouts is discussed. The rationale of adopting a small swept volume DI diesel engine as the donor for the block, crankshaft and pumps is explained, together with the engineering reasons for the final choice of donor engine and the reverse engineering necessary to fit the gasoline-specific parts to the original diesel components. Analysis of the cylinder head cooling jacket based upon assumed flow patterns in the cylinder block is presented, together with the results of structural analysis of the cylinder head. There is also some discussion on the engine's initial durability under the arduous high-load conditions provided by the first area of investigation, turboexpansion. Copyright © 2006 SAE International.