Traditional projection engine designs are mostly based on propagation of light through standard components, such as, dichroic filters, lenses, polarization beam splitters, prisms, etc. These components are usually held individually using optical mounts and assembled together on an optical bench such that all the components are aligned properly. Even in high volume production environment, it tends to be tedious and expensive. With the advancement of light pipe based illumination system, e.g. the Wavien patented dual paraboloid reflector system, and light-pipe based polarization recovery system, it would be advantage to design a light-pipe based projection engine for a complete light-pipe based system for low cost and space saving applications. Except the projection lens, a totally light-pipe based projection engine is described. It consists of an etendue efficiency illumination system using the dual paraboloid reflector system with a lensed tapered light pipe at the output. The output is then directed into a light-pipe based polarization recovery system such that the output is polarized. The polarized light is then separated into its individual RGB colors, and is directed into the corresponding HTPS imager chips separately by the use of light pipes, prism, and beam splitters. The outputs from the imager chips are then recombined by an X-cube and projected onto the screen. A design has also been made for LCOS imagers. The folding and unfolding properties of the light pipe are used in this case resulting in a more compact projection engine. This light-pipe based system uses low cost optical components and takes up much less space than the traditional projection system.