I think I got a Rossi, Stels, AMEand a Cox Conquest in there too. If you want a fast motor, I think a front intake is faster. That is likely why they don't make them any more. The team race diesels use them because of the tighter base compression giving better mileage, but I think the friction frome the rotor slows the little ones down too much. The smallest RR I could find is the K&B .21 from Mecoa @$200. There may be some little diesels I amnot aware of. Any front intake better quality european motor would likely matchthem for perf. and maybeprice. Novarossi, Picco, Profi, Fora.