Always have been curious how car manufacturers determine the redline of an engine. And wouldn't it change based on modifications made to it such as new pistons.

 

I think the head has more to do with the redline than the bottom end.

 

Why over-engineer the bottom end when the topcan only go so high?

 

usually when the engine wont make any more power and the curve drops off they plop the redline a few hundred RPM in front of the drop.

a lot of it also has to do with what the engine can take

 

lol everyone is reiterating [sp?] the question, the redline is where the engine can't take any higher rpm. the question is how do car manufacturers know when that redline is?

 

Calculus.

 

Care to elaborate?

 

its alot of factors, but obviously reliability is huge for a honda. there are things like rod to stroke ratio, hp @ rpm's, basicaly there is really no real formula to figure redline on an engine its going to be different for every engine because of its design and limitations, also its uses

 

Er, well it's no secret that everything in the universe can be translated into some sort of mathmatical equation. But calculus is really whatallowed man to applyideas into real, workable situations. As a professor of mine put it, "Man had the ingenuity and the ambition, butno way to apply it, until calculus. Calculus is what made man's dreams into reality."

Basically, all the sciences that you can think of to determine the strength of parts, and the stresses that would applied on them within an engine,all revert back to calculus for calculation.

:edit: That's not to say engineers go back and calculate every possible variable for every single moving component in an engine that could cause stress or failure at a given rpm, or maybe they do I'm not an automotive engineer. But I assume like most things with experience you get good at what you do, and can determine at least general limitations quickly.

 

Yea I was just curious. I knew redline was around where the engine got maximum power, but I figured that would not be the most accurate method in determining where to place the actual redline mark, and the associated rev limiter as well.