Don't know what to tell you.

Sure, factory engines are limited, but when you start adding aftermarket parts, those numbers no longer apply. When you significantly raise compression, you are adding torque - if you increase stroke, you add torque, if you add air flow, you add torque. One can't say an engine with 10:1 compression will follow your logic on btq per liter when you bump that compression up another 20-40% to 12 or 14:1 - thermal efficiency increases along with it.
There are several ways to make power: increase the rpm capability, increase the displacement, increase the flow etc.
Here's another members' dyno thread where he shows good gains, it's not just the two engines posted in this thread...
Comment