If the Magnum 1.08 is comparable to the OS 1.08 in power then yes it would be a good choice for the esm stuka. I used an OS 1.08 in a 1/4 scale triplane that was scratch built and it proved more than enough juice to fly the bird. I also know of a dauntless dive bomber that has been flying for years on an OS 1.08. The dauntless weighs well...and I mean well over 20 pounds. Stuka dive bomber...Dauntless dive bomber.....if the magnum is compareable to the OS it will work and you will be pleased. I would not hesitate to use it. Prop it right!