As earl started the closest 4 stroke is the Saito 40. it will turn a APC 12x4 at around 11,000 on 30% with a 4-6 ounce tank. The OS 26/30, magnum 30 will not be anywhere close to the same power as the Saito 40. The saito 40 will be down power by a little bit over the .32 Two stroke but not by much. the next up is the Saito 56 but is about 5-7 more ounces in weight and will need a larger engine mount and tank. more weight.