rmemedic
Well-known member
Hmmmm ...
I haven't found a version of this picture that I can embed. And, I realize that this picture shows Ford engines, and we are talking GM here ... but GM doesn't have an overhead-cam V8 (perhaps with good reason, as you shall soon see). Look about halfway down this thread for the picture that I am talking about.
http://forums.bimmerforums.com/forum/showthread.php?t=1880105
On the left, is a 4.6 Ford DOHC V8 "mod motor" with the valve covers removed. On the right, is a Ford 5.0 pushrod V8 with the valve covers removed. Wee bit of difference in size, isn't there? Even though the 5.0 has a larger displacement.
Say what you want about pushrods ... but the traditional American pushrod V8 is packaged very well. It puts a whole bunch of cam-actuation nonsense into the valley (space that is otherwise pretty much good for nothing) that the DOHC engine needs to have out on top, where it adds to the height and width of the engine.
The Corvette's Gen 5 Chevrolet V8 might have pushrods, but it also has direct injection, variable valve timing, and cylinder shutdown at part load. It is a darn good design.
No, you can't make a pushrod engine do 20,000 rpm. But for the rev range in which practically every automotive engine operates ... it's irrelevant that it won't do 20,000 rpm.
As for the leaf springs ... There is precisely zero similarity between the Corvette's independent upper-and-lower-wishbone front suspension in which the spring acts only as a spring (and plays no role whatsoever in guiding the path of the wheel spindle or in steering), and the horse-cart solid axle leaf spring "suspensions" that gave leaf springs a bad name. In the Corvette application, the transverse leaf spring packages very well by not needing tall struts extending above the top of the front wheel (thus allowing a low hood) and it fits across the chassis below the front of the engine in a place that wouldn't otherwise be used for anything. You can tune a transverse leaf spring to serve both the spring function and an anti-roll function by careful placement of the pivot points - can't do that with coils.
This is indeed GM tech at its finest. And that's intended as a compliment, not as a bash.
Disclaimer: I've never owned a GM vehicle. That doesn't mean that I don't give credit where it's due.
FWIW ... The Vette engine makes more horsepower bone stock than any street-legal, emissions-legal, automotive engine Honda has ever built!
Word. I couldn't have explained it any better.