No Free Lunch, hp cid torque gearing
There is zero power in oxygen. Power is in the fuel. And it’s not only how much fuel you can burn, it how well you burn it and how many times per second you can burn it.
That’s the simple answer to it. You can look at a dyno sheet and see how much fuel an engine is burning and know if it’s competitive or not.
Yup!
How much fuel an engine can burn is dictated by displacement.
The RPM capability is dictated by the airflow.
The combustion efficiency is dictated by compression.
Output efficiency is dictated by friction.
"Airflow" covers a lot of ground, because it has to take into account pressure drops, recovery, and temperature gain/loss as well. Friction matters more than most people realize - and not just in the rings, though those have probably one of the biggest impacts, or is the one which we have the most control over.
The typical hot rodder gets all these wrong. They run too much displacement for the job, then put a tiny head on it that keeps the rpm potential under 6k to avoid spending money on good springs (but muh torque!), then they run low compress "for pump gas" and then use ancient ring designs and cylinder prep that makes as much sense as driving with the parking brake on. Then they seem puzzled by 8mpg and the fact that a Camry can outrun them on the onramp. Shameful.
The way a motor is fueled also matters. TBI/Carb are entirely different rules, than port or direct injection and not just because of 'wet flow' - it's all a matter of vapor pressure which requires a balanced approach to induction.