The main purpose of this work is to convert the mechanical injection system of a single cylinder diesel engine to an electronically controlled dual-fuel system. The new system consist two different injectors. First injector supplies the LPG (liquefied petroleum gas), the other one supplies the diesel. LPG is supplied via a port fuel injection system located in the intake port of the engine and the diesel injected directly into the combustion chamber before top dead center (TDC). All injectors were controlled by Programmable Logic Controller (PLC). After the adaptation and tests, the single cylinder Lombardini LDA 450 type diesel engine was modified to a high pressured PLC controlled dual-fuel research engine. (C) 2014 Elsevier Ltd. All rights reserved.