It would come down to "difference in friction". There's an "App" for that, well...not an app but a formula!!
The engineering of a bearings Babbitt lining is usually completed during the design of the machine. In selecting the proper type of Babbitt for a particular job there are a number of factors to take into consideration, the most important of which are as follows:
1.Surface speed of the shaft
2.Load that the bearing is required to carry
There is no doubt that if a bearing is to be highly loaded in relation to its size, a high tin alloy is desirable; whereas for much slower speed work and less heavily loaded bearings, a lead-Based Babbitt may be employed, and is far more economical.
1. Surface speed of the shaft: (The number of feet traveled per minute by the shaft circumferentially.)
Formula: (Pi x D x RPM) / 12 = S
Example: Determine the surface of a 2 inch diameter shaft going 1,400 revolutions per minute (RPM)
(Pi x D x RPM) / 12 = (3.1416 x 2 x 1,400) / 12 = 733.04 Ft/min
Where: Pi = 3.1416, D = Diameter of shaft, S = Surface speed of the shaft
2. Load bearing is required to carry: (the weight which is being exerted through the combined weights of the shaft and any other direct weights on the shaft and measured in pounds per square inch.)
Formula: W / (I.D x L.O.B.) = L
Example: Determine the load on a bearing of a 2 inch I.D bearing, 5 inches long and carrying a weight of 3,100 lbs
W / (I.D x L.O.B.) = 3,100 / (2 x 5) = 310 Lbs/sq.in
Where: W = Total weight carried by bearing, I.D = Inside diameter of bearing, L.O.B = Length of Bearing, L = Load bearing required to carry
You can actually calculate the amount of friction gained or lost simply by knowing the speed of the shaft, weight carried by the bearing,ID of the bearing, etc, etc.
I doubt you could measure it on a Dyno because threre are too many variables, it's like building two engines exactly alike, and I mean exactly!! The chances of them both having exactly the same horsepower is next to none, even though they were built the same!!
Treblig