Brian

As I recall a well tuned and leaned aircraft engine will produce about
15HP per US Gallon per hour.
This works out to about 4 HP for liter (3.9 but rounded for
simplicity)

So 20 Liters per hour should only be producing about 80 HP. Most 152
engines are not run this lean nor are they will tuned anywhere near
enough to do so. So this is really a best case Scenario.

If this applys to the motorcycle engine which is probably tuned much
better than the 152 engine then it is only producing about 40Hp ant 10
liters per Hour.

Brian
CFIIG/ASEL