Dynamic Cubic Inch

Works sucks, a little too much time on my hands today.

It drives me a little crazy when people talk about engines for performance and or fuel mileage they leave the rest of the drivetrain as an after thought to me it's all one thing, eg. 360 gonna make more torque then 318/340 so 360 better or 318 smaller so its gonna get better mileage than 340/360 etc... which both cases are generally true cause most people are gonna run 3.23 or 3.55 gears.

I think you can look at cubic inch in the same way people are starting to see Compression Ratio forever people only talk about Static CR but with Dynamic CR people are now realizing the relationship between Static CR and the cam in a running engine is what's more important. And I say Same with CID, with engine size and gear ratios. A 451 is it static size but an engine is only good if its running so a 451 at 2000 rpm would 45100 cubic inches and a 225 /6 is half is size but at 4000 rpms it would be 45000 cubic inches practicality even In size and potential. But for a /6 to make same power as a 451 it would take the same air flow (fuel and air) and twice the rpm. A /6 could match the power of a 451 but only if the 451 was built to 300 hp or less mainly cause of the weak /6 head not realy cause of its engine size and I used /6 vs 451 as an extreme, for most its gonna be 318 vs 360 vs 408.

Though a /6 could only ever hope to make half the torque as a 451 but with twice the gear the tires would see the same torque output. Cause everything is in mathematical relationship to one another cause torque is only one function of horsepower the other being rpm so in other words horsepower is a function of torque (mainly engine size) over time (rpm)gear ratio). So if one engine make 500 lb-ft and another makes 250 lb-ft but at twice the rpm so twice the gear ratio required for the 250 lb-ft engine, it would need to be twice as low effectively doubling the torque and equalling both engines. It takes a certain amount of fuel and air to make a certain horsepower with a certain efficiency, Horsepower is the ability to do a certain amount of work in and certain amount of time so if you make 300 hp /6 and 451 at the same efficiency the the torque numbers don't really matter, cause they both can do the same amount of work in the same amount of time eg quarter mile, top speed etc... if both both optimized for the same task (gear ratio) but say you ran both on the same gear ratio then you've optimized both for different task, ones gonna have more top speed the other quicker acceleration (quarter mile).