Andy, if your CS has 180 degrees of exhaust or more, then it won't be able to resonate like a 1/2 A Speed engine should with much more than a 4 x 4 prop [with really skinny blades]. This really limits it's usefulness to very small, thin and light planes.
Figure that it's designed to run at about 40,000 on FAI fuel.
If you can meet all the conditions required, then it ought to fly a RC plane at 150 mph +