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.
Check the engine code in the VIN. It is the letter in the 5th position from the left. M - 350 cu. in. 150 hp N - 350 cu. in. 175 hp R - 400 cu. in. 170 hp S - 400 cu. in. 200 hp T - 400 cu. in. 230 hp
Stock Harley 2012 RK with the 103 motor puts out 81 HP
1 HP electric motor = 1.5 HP hydraulic motor so for a 3 HP electric motor you would need a 4.5 HP hydraulic motor. Also for your information a 1 HP hydraulic motor = 1 2/3 HP gasoline engine.
if it doesent already have them it should, unless you wer to put very small pipes on it also
103 HP, with manual 3 speed trans, 85 mph.103 HP, with manual 4 speed trans, 88 mph. 103 HP, with automatic trans, 83 mph.
They had either a 216.5 cu. in. with 92 HP or the 235.5 cu. in. with 105 HP. No 95 HP engine was available in 1951.The 92 HP car had a top speed of 75 mph. The 105 HP car had a top speed of 80 mph.
1.
360
A 6.2 liter motor is around 400 cu in. A 350 cu in is a 5.7 liter.
If it can be adapted to fit, it is a little more powerful
Put a 12 hp motor on it.