Questions and Answers NOTE—Readers are invited to send in questions, which will be answered in the order received. Names are omitted from questions unless otherwise specified. Finding Engine Horsepower To the Editor: I note in a recent issue of FIRE ENGINEERING a question on horsepower of gasoline motors. The S. M. M. T. formula given below gives about the nearest to actual delivered horsepower of any that I have seen. You might pass it on to your readers. H.P. = 0.45n (b1.18) (b+s) Where n = No. cylinders b = Bore in inches s = Stroke in inches There is also a French formula given which gives slightly different results, but is useful in comparing motors at various speeds. H.P. =c n b2 s r Where c=(for 4 cylinders) 0.000082 c =(for more than 4 cylinders) 0.000071 n = No. of cylinders b = Bore (inches) s = Stroke (inches)…
