Abstract: A model airplane engine mounting system for isolating vibration between a model airplane and a combustion-type model engine which mounting system is connectable to an upright fire wall panel of the airplane. The device includes uniquely configured two-part grommets which act between a split spool and a cylindrical mounting boss of the engine mounts to isolate both fore-and-aft thrust and shear or rotational torque, harmonics, and combustion outputs from the engine. The grommets, in combination with two-part t-section spool halves, provide a captive engine mount system which is easily connectable to the fire wall by conventional bolts.