<div class="htmlview paragraph">This paper compares different engine solutions for the FIM MotoGP World Championship. Starting from the general guidelines given in a previous paper [<span class="xref">2</span>], in this study the specific features of each engine architecture (3 and 4 in line, V4, V5 and V6) are considered. 1-D engine simulations, based on a previously validated model, are extensively used to optimize each solution, as well as to provide a comparison among the engines in terms of dynamometer performances. Some issues concerning engine balance, engine overall dimensions, intake and exhaust system lay-out are discussed. Finally, the influence of the engine on the bike acceleration is calculated by means of a simple simulation at the Mugello track.</div> <div class="htmlview paragraph">The comparison has shown slight differences among the proposed configurations. Globally, the V engines, with four and five cylinders, have resulted to be the best solutions.</div>