Response to January's first annual Ward's Best Engines of 1995 feature has been overwhelming. WAW readers, from engineers to executives to suppliers, phoned, faxed and wrote to express their opinions and to support -- or contest -- our 10 Best Engines of 1995 selections.
The story behind the "Best Engines" story is what's in store for the future. Our interviews with some of the engineers responsible for development of the Best Engines of 1995 proved provocative -- and the Best Engines competition primed these engineers to be uncommonly forthcoming in discussing their future developments and ideas.
Take 5-valve/cylinder technology.AG's Audi unit and Ferrari SpA both recently unveiled intriguing 5-valve production engines for 1995. In Ferrari's case, the numbers are small, but Audi's 5-valvers (one turbocharged) are for volume-produced cars. The obvious claims for these new multivalve engines are greater efficiency and higher available engine operating speeds.
But Bruce Coventry,Motor Co.'s manager, small 60-degree V-6 engine systems modular engine design (whose 2.5L Duratec V-6 was one of our 1995 Top Ten engines), isn't too enthusiastic about the 5-valves gaining a following.
He says 5-valve engines are okay for limited-application purposes, but volume manufacturers likewould be hard-pressed, at least for now, to produce 5-valve engines for vehicles in Ford's traditional affordable segments.
Saab AB's (another Top Ten winner) Per Gillbrand echoes Mr. Coventry's caution: "Saab believes that some turbo boost pressure is more efficient than variable valve timing, variable inlet manifold (design) and five valves. Of course, five valves improve the basic engine, but we believe that the cost/benefit over four valves is critical."
And theengineers responsible for developing the impressive 2.3L Miller-cycle V-6 also are skeptical. "Even generally speaking," they say in a fax from Japan, "we think the improvement in performance by adopting 5-valve over 4-valve (designs) is not as much as some people believe. We think that adopting 5-valves will be limited to some naturally aspirated, high-performance engines or extremely long-stroke engines which have difficulty in securing valve areas."
Bottom line, if we can take these statements at face value (cagey engineers have been known to throw out the odd red herring): don't look for 5-valve/cylinder engines to lead the next wave of performance and efficiency enhancements for gasoline engines.
If it's not 5-valvers, then what's next for near-term engine development?
While there's plenty of talk about turbine-alternators, fuel cells and battery-powered electric vehicles, most automakers' engineers believe the piston engine still has plenty of life -- and the most viability for the near future. But more sophisticated "hybrids" of the piston engine may be in the works.
AG's engineers "don't see a serious alternative to the spark ignition piston engine. Now, as before, it offers a great potential for ongoing development." For example, they believe their existing V-8 engine design "will meet the emissions and fuel economy standards in the not-too-distant future, with the exception of extreme examples such as the zero-emission vehicle (ZEV) standards in California."
Corp.'s Powertrain engineers are similarly confident about the piston engine, but they are known to be working on a variety of alternatives, including study of the Miller cycle. Sources say that Ford, too, is taking at hard look at Mr. Miller's process.
, first to bring Miller-cycle to market, is understandably ardent about the engine's near-term potential. It says the Miller-cycle's efficiency and output can be further improved. Moreover, its engineers say the Miller's emissions output can be lowered -- to levels equalling direct-injection diesels -- by adopting lean-burn technology.
As for alternative engines, Mazda engineers say, "If we dare to propose an example, it would be a highly compressed, 2-stroke uniflow diesel engine with a Lysholm compressor. If it incorporates the Miller-cycle with late closing timing of the exhaust valves, as seen in large diesel engines on ships, there may be a new potential. By combining a lean-burn engine with the Miller-cycle, we believe an ideal automotive engine can be created. We are currently researching and developing this ideal engine."
Although Mazda apparently envisions a future for the star-crossed 2-stroke, the Big Three recently have said precious little regarding its status. Even Ford, lately the most aggressive of the Big Three in expounding the 2-stroke's production viability, has fallen tight-lipped. At press time, Perth, Australia's Orbital Engine Co. announced its 3-cyl. 2-stroke had been independently tested -- and passed -- European emissions standards for 1999 and that low-mileage engines are complying with California's ultra-low emission (ULEV) standards.
Orbital's numbers may elicit further 2-stroke news from other manufacturers.
So, in absence of 2-strokes or diesel Miller-cycle engines, what new engines look to be strong candidates for Ward's Best Engines of 1996? Aside from this year's winners (automatically nominated), we're anxious to see's 1.9L direct-injected turbodiesel; Ford's 3L Duratec DOHC V-6; Audi's 1.8L 5-valve I-4s and 's all-aluminum 2.7L V-6.