20
There is not such conversion of displacement to HP. You have what is basically a 17 cu. in engine and that would seem to be and 8 to 10 HP engine in an OHV configuration.
The conversion factor of 735.5 is used to account for mechanical losses in the conversion of horsepower (hp) to watts. This factor is commonly used in industry and reflects the typical efficiency of the conversion process. The more exact conversion of 1 hp to watts is actually 745.7, but 735.5 is often used for practical purposes.
hp
approximately 30 HP
The conversion factor for converting from kW to horsepower is 1.34. So, kW x 1.34 = hp
The conversion factor is 0.746. So, hp x 0.746 = kW
To convert bhp to kW simply multiply the bhp figure by .7457
The conversion factor is 1.34. So: .78 kW x 1.34 = 1.0452 hp
13.6
5 hp
The conversion factor is 746.27: hp x 746.27 = watts
Six hp, according to the conversion tables.