Lenz's effect heating with RV motor 001

This is my first step to develop a system to heat my house with hot water.
I have done first test with a 1/3hp RV motor but there is more drag that I tought so I move to a 3hp RV motor. I must modify the system to make water flow in a 1 ou 2 liter tank so that way, it should by easier to transfer heat from the copper tube to water.