I have noticed that the "Performance" vehicles of say Ford, Chevy, Pontiac(i.e. Mustang, Camaro, Corvette, Firebird) have much lower redlines then the "Performance" Cars of Nissan, Honda, Mazda, VW/Audi. For example, a Mustang SVT Cobra R has a redline of 6800, and an Integra Type R has like an 8400 rpm redline. And horsepower to displacement is another thing. Type R is like 109hp/liter, where as the Cobra R is 71hp/liter. Is it that the redline varies so much because, Honda has a better built engine, meaning it's balanced better then the Ford engine. In my theory, the Ford engine isn't balanced well enough to handle the high RPM and would essentially shake itself to death. Or is it that it's harder to balance a V8 then an L4. But Domestic l4 don't have as high RPMs as imports do. So, am I right in that assumption?

 

It's more political than engineering; Japan (and many other countries) taxes cars based on engine displacement. Displacement equates to torque and power is torque times engine speed. So to achieve high power and with small displacement, you must spin the engine faster. Of course the high revving engines must be engineered properly to compensate.

 

In my theory, the Ford engine isn't balanced well enough to handle the high RPM and would essentially shake itself to death. Or is it that it's harder to balance a V8 then an L4. But Domestic l4 don't have as high RPMs as imports do. So, am I right in that assumption?[/QUOTE]

An 8 cylinder engine is inherently smoother than a 4 cylinder. It's not an issue of balance on late model domestic (US) engines, it's things like cheap rods, cast cranks and costs associated with building a high rpm engine. Not to mention Honda's VTEC systems kick ***.

 

You left out perhaps the BIGGEST reason why this is the case: corporate culture. When it comes to building motors, big, low-revving motors has always been the American way of doing things. Companies like Ford, GM, and Chrysler have been building such motors for decades. That's what they know how to make. That's what they have the tooling to make. That's what customers have come to expect. And that's what they will continue to do. Japanese and European automakers, on the other hand, have always built smaller, higher-revving motors. And they will continue to produce such motors for the same reasons that American automakers will continue to produce larger, lower-revving motors.

So why did this come to be? Perhaps alot of it has to do with the fact that the US is so much more resource-rich than Europe or Japan. As a result, American automakers did not have to pay such close attention to optimizing their designs. Building something bigger to make more power was always easier and cheaper. But in Europe and Japan, there was more of a need to get more from less. Things are, of course, changing here in the US as well. But instead of building European or Japanese-type motors, American automakers have concentrating their efforts on more careful design of the basic American style motor.

 

Id just like to point out the fact that Honda among other Japanese car manufacters, (Suzuki, others Im sure) began with building motorcycles and small gas engines that require hirgher rpms to produce power.

 

one thing i am surprised no one mentioned is reciprocating mass. it is a LOT easier to build a high rpm engine when you are dealing with fewer, smaller, ligher parts.

I would say the assumptions of the original poster are completely wrong.

US automakers are making engines that they think appeal to most americans, which are torque producing low revving engiens in general. most americans are NOT comfortable with revving to 8000rpm.

If you go back and look at some of the historical engines that ford and chevy built you will find that a lot of them are capable of being revved much higher. for example some of the older 302s built in the late 60s and early 70s revved past 7000 rpm but didnt sell as well in general since the customer base was used to only revving to 4-5k rpm.

Lastly, the Ford modular 4.6 v8 has been proven to be able to rev way beyond stock rev limit with proper cams and valve springs. A while back a guy in a car club i was in had soem great info on a Lincoln Mk VIII that had the 4.6 v8 in it and was making power to nearly 10krpm on a stock bottom end. I found it hard to beleive but he felt it was a very reliable source in teh modular v8 world.