Vasec,


In general, engine performance can be compared by the RPM they can spin a given prop...
But this obviously has its limitations.

If you compare an A-brand .50 to a B-brand .50, you would normally take an RPM reading, with an 11x6 prop and another, with a 10x6, to see how much each engine unloads in high speed flight.

The MVVS .49 is probably for lower RPM than some other engines of its size bracket.
It accentuated high torque at mid-high RPM.

If you use it with the #3248 tuned silencer and high speed is your goal, you would want to prop it so it will spin around 14,500 RPM, on the ground. With the tuned silencer tucked-in to minimum length, it would unload to about 16,000 RPM, in a high-speed pass.

If you try propping it for more RPM, its narrow passages will not allow more HP.


The ST Blue Head was a baffle-piston, loop charged engine, with even lower RPM capabilities.

It was used at some point for F3A. I think Ed Moorman used one.
But it will not make the same HP as the smaller MVVS.

It could, however, spin larger props, without getting out of the 'meaty part' of its HP curve.