Pure championship engine. I measured it to be 8mm stroker and a 110mm piston. Guy said he thinks its its a 4mm. Either way it would be 823cc or 853cc. The cases are custom machined for the stroker and to put a larger cylinder in. This is really a one of the kind raptor engine. The cases are in very good shape. Crank is tight. Piston is good. This bottom end would be great for a all out drag bike.