There are 60 minutes in an hour, so to find the hourly rate, you would multiply 3.14 by 60, which gives us 188.4. If the rate is 188.4 gallons an hour, then we can divide 329 by 188.4. The full number would be 1.7462845011, but you can simplify that. If you need the minimum number of precise hours needed, then it would be 2. If you are allowed a small amount of error through simplifying your decimals, then you could say about 1.7.