Comparing engines is a little difficult once you get past peak horsepower and torque numbers, since there is a multitude of factors to consider. If only there were a tidy way to compare the efficiency and power potential of different engines. Well, Engineering Explained posted a video explaining precisely that formula.
Read the full article on Hagerty.com: https://www.hagerty.com/media/maintenance-and-tech/use-this-formula-to-determine-the-best-engine/
As an engineer I found his explanation interesting. It would have been nice if he had quickly included the conversion factor for torque from foot-pounds to Newton-meters (1.3558). He included the BMEP on the new Corvette engine but didn't include the Ford Coyote engine, which has a BMEP of 14.31. So if the regular Mustang GT engine has a BMEP of 14.2 and the Coyote is 14.31, is the additional cost worth it? His evaluation comes down to producing the maximum amount of torque in the smallest volume of displacement. Probably why the Porsche boxer engine has a good number.
did not even try to watch video. not worth 16 minutes of streaming video to ascertain basic ideas. If there is a formula, then there is an exact solution for all variables. Just the premise of assuming an explosion (almost instataneous event) versus combustion (occurs over time depending on many factors) renders any exact formula suspect.
Very interesting dissertation about engine power theory. To me, however, there was a glaring omission and that was the exclusion of the current NHRA Pro Stock 500 cubic inch V8. These are naturally aspirated fuel injected powerplants limited by the rules to 8500 RPM. They are reported to develop about 1300 HP on racing gasoline, and it would probably skew the whole measurement chart a bit. Even more impressive in my estimation are some of the Sportsman-class engines that are also naturally aspirated and develop four-figure horsepower numbers. A Super Comp dragster with a 632 c/i engine will make 1230 HP at 7000 RPM with a single four barrel carburetor. And I still have a classified spec cam that I had Yoshimura grind for me for a 1971 750 Honda that created so much cylinder pressure that not only would the electric starter not turn it over, the kickstarter was useless as well. It made 165 horsepower at the tire, but the transmission didn't like it for very long.