Engine's run about .5 lbs per hour per hp. 500hp=250lbs per hour, 750hp=375lbs per hour, 1000hp=500lbs per hour. divide by 60min to get per min. figures, 500hp=40lbs per min.
The fuel flow changes with the hp being made, not by the ci (size) of the motor.
A natural 500hp engine makes 500hp at the crank, each piston is making 62 hp. If the engine was a blown to make 500hp, the blower might take 75 hp to turn. so the crank puts out 500hp but the pistons are putting out 71 hp per piston. so you need to burn enough fuel to make 575hp so to make the same power a blown engine uses a higher .56-.6 lbs per hp. The larger blowers use more power and require up to .6 lbs per hp.
Most boat mechanics also like to run the blown engines rich to help cool the combustion chambers. ie. 11.2- 12.0 A/F ratio.
When you run water injection you do not want to run a rich engine . 12-12.5 is better. A rich engine with water added is too much liquid in the combustion mix.
(Just a few notes I believe are true):wink: