Air cooling is a simple thing but complicated to compute.  There are many variables and the velocity and temperature of the air is different at different locations around the engine.  If memory serves me correct, in an air cooled forced convection situation, the heat transfer is roughly proportional to the square root of the velocity.  So 16 mph is certainly much better than zero.  As the speed goes up so does the cooling but at a diminishing rate.  This increase roughly matches the engine's need, the faster the engine goes more heat is generated and more air flow is created to help cool it.  Same with a lawn mower engine with a fan, the faster the engine runs the faster the fan turns.  So in high gear you generally run cooler at a given speed than in a lower gear because you have more air for the RPMs.

At some point the ability of the material, aluminum or whatever, reaches its limit of conduction speed from the inside to the outside and additional air speed doesn't help, but I don't think the Savage goes that fast.

I know a lot of technical guys are in this forum so let me know if I am wrong about the square root thing.