Abstract: A water cooling device for a model toy engine comprises an engine, a radiator, a pipe, a cooler, and a water tank. The radiator is fixedly installed on the engine. The radiator contains water and has a water outlet and a water inlet on the top thereof. A pipe interconnects the water outlet and the water inlet. A cooler and a water tank are installed to connect with the pipe. The heat generated by the engine boils the water inside the radiator into vapor. The vapor flows into the pipe, and the cooler cools the vapor into water, and then the condensed water flows back to the radiator. The cooling cycle is repeated persistently to dissipate the heat generated by the engine. Therefore, the present invention can cool the engine without using any motor or pump. Further, the present invention can prevent the engine from overheat or burnout, avoid horsepower falling, and prolong the lifetime of the engine.

Abstract: An air intake structure to increase air intake time for model engines includes at least one channel on the bottom wall of an air inlet of a model engine. The channel is inclined and directed inwards from an outer side of the air inlet to mate an opening of an air intake passage formed in the middle portion of a crankshaft. Thereby the amount of fuel gas entering through the passage into a crankshaft chamber can be increased gradually to lengthen fuel gas intake time to achieve a thorough air and fuel mixing. Fuel consumption can be reduced and crankshaft rotation is more stable. Engine performance also can be enhanced.