Rod, I am on the other side of this one. I love the high revving small sports car engines. Even back in the 1970s in club racing there was this great rivalry between the Vette and the Lotus Elan. The Vettes had 427 V8s and the Elans had a 1.6L DOHC I4. The races were very competitive. The Vette was a little better on the straight and the Elan won the corners (this was SCCA track road racing). My brother and I (and later my father) drove MGs, Alfa Romeos, Triumphs and Austin Healeys. Just getting to the races in rural West Virginia from Washington, DC was a blast. But, I digress (so what is new).
With modern materials the higher revving engines will still last a long time. They are also, in general, more flexible. In a sports car I like that.
> One thing I was suprised was, > though, was the relatively low > power density of the Corvette > V6 engine.
I'll assume that you meant the V8 engine.
In addition to what others have mentioned, I'd be willing to bet that the equivalent torque output of that Corvette V8 engine is much higher than the torque output of that high-strung Ferrari engine. While horsepower is nice, it takes torque to get a heavy vehicle moving!
Nice short rigid cam chain, easier to achieve accurate cam timing over the life of the engine.
Lower horsepower per liter is not a bad thing, there is less stress, less load on parts. Can easily result in longer life, maybe not important for a Vette. The same engine in trucks, life is a design consideration.
2 cams does give you the ability to alter the timing of intake and exhaust separately. However the Vette gets excellent fuel economy.
As in all things, tradeoffs are always there. This is a great solution.
I will take mine with the radar/laser stealth paint please.
If one is familiar with engineering history, some of the "novel" ideas are not totally so. Steam engines have employed variable valve timing for well over a century. It allows them to vary the steam admission cutoff so as to trade between efficiency and peak power. They also to adapt to varying speed.
As for "advanced" materials, the higher class cars of the 1920s used lots of aluminum, and they reinforced it with a fibrous composite called wood. The result was a light strong structure with excellent vibration damping.
Some of those same cars also used aluminum engine blocks with cast iron cylinder sleeves.
Glad to see they have re-invented some of these technologies.
GM's philosophy about the small-block V8 engines, like the one in the Corvette, is that overall efficiency (fuel economy), power, and minimal external size (keeps the Corvette's hood line low) are the key criteria. Admittedly it might make better engineering sense than marketing sense.
Power density as expressed in hp/liter is an interesting number, but is not ultimately important if the power and economy are competitive. The overhead valve, but cam-in-block design is a smaller overall package because there are not cams sitting high above the cylinder heads. It competes well in power and economy, but does require more displacement to do so as compared to a DOHC motor like the BMW, Ford 5.0 or Toyota V8 engines.
GM small-block engines are well known in the aftermarket/hot-rod world because the larger displacement responds well to power adders like superchargers or turbos.
Agreed that Ford has raised the bar with the materials in the new F-150. 700 lbs of weight savings is a big deal.
Chuck, there are a lot of wonderful cars here. I want one. I am just not sure of which one (although the Viper has always been a favorite of mine).
One thing I was suprised was, though, was the relatively low power density of the Corvette V6 engine. If I am correct, it gets 100.8 horsepower per liter. The Ferrari 250 GTO in the 1960s got 100 horsepower per liter with six two barrel downdraft Weber carbeurators and normal aspiration. It seems that Chevrolet could have gotten that type of output from a smaller engine.
I really wish Ford had produced the Ford I concept car. They would have taken a lot of business away from the Europeans and probably could have sold them in Europe.
The use of aluminum and new, high strength steels is probably the most important thing shown at the show. This trend is important if new fuel economy standards are to be met.
Although plastics make up only about 11% of all US municipal solid waste, many are actually more energy-dense than coal. Converting these non-recycled plastics into energy with existing technologies could reduce US coal consumption, as well as boost domestic energy reserves, says a new study.
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