Tito F. Hermoso / Brent Co, Honda Press | July 13, 2010 16:28
What's the next step in engine technology
Thirty Five years ago
Once upon a time, life was much simpler. Diesel engines were heavy, smoky and slow but they were thrifty. Normal engines were quick and bigger engines were quicker. Small 4-cylinder engines needed revs and more than 3 gears to get you going, while V-8's could fly on only 2-speed dynaflow hydramatics and revs as low as 2,500rpm.
Then came the era of high octane fuels, thanks to the discovery of Tetra Ethyl Lead. This led to higher compression ratios. With this, Europeans penalized by high fuel taxes, could make their small and light cars with their small engines and 4-speed manual gearboxes, show a clean pair of heels to the big block Hydramatic V-8's of portly American cars.
Get what you pay for
Even the tuner's life was simple. Wanted more power for you little 1600cc engine? Whether Toyota or Alfa-Romeo, all you had to do was fit in bigger pistons, bigger valves, bigger exhaust, bigger intakes, bigger carburetors and wilder cam profiles. On the latter, the sharper the cam lobe, the greater the power kick at high rpm. That compromise would be between the degree of peakiness of the the engine and lumpen idle. You can choose between high end power or mid range pulling torque. Nice and simple.
Then the Doctors found out that lead was bad for you, and with this, started the cleansing of lead, leading to the cleansing of emissions. Now this was bad for engine performance. What was once considered a given - sprightly pick up from idle to mid-range rpm - was lost. Exhaust Gas Recirculation and Catalytic converters choked the engines to idle badly at high rpm and strangle any feel of acceleration, much less get up and go. This was bad. Meantime, safety regulations were making cars heavier and heavier. Performance, never mind high performance was becoming a bad word. Double bad.
More air for the asphyxiating
The rallying Swedes fought back with turbos. The Americans just made bigger and bigger thirstier engines as their untaxed gas remained cheap. A few Brits and Italians dabbled with multi-valve heads. Then Honda introduced the CVCC - the stratified charge engine. It cleaned up the exhaust without resorting to asphyxiating paraphernalia. It gave hope for car lovers that you can have your clean air with easy gap-filling pick up. Alas, engines had hope to breathe easier.
Meantime, automatics got lock-up converters and 5-speed overdrive gearboxes became the norm. Computers got involved integrating fuel injection and emissions control. Later, even the automatic transmission became a slave to the computer, along with shocks, anti-roll bars, brakes and air conditioning. With better and frequent fuel-air mixture control, engines started sprouting more valves than the traditional 2-valve per cylinder heads. This became the 16-valve revolution. Things got better with valve timing control of intake and exhaust valves. Throttle body control followed. With multi-valve technology, came the revival of superchargers and turbochargers. Soon diesels were given the multi-valve treatment, and the manufacture of lightweight variable geometry turbos finally gave diesel engines the performance edge it needed, without the lag, to be a viable alternative to gasoline engines that are continually being choked by Euro 3, 4 or 5 emissions control.
Vary the lift
But by far, the biggest jump in performance and efficiency was the introduction of Honda' variable valve timing with variable valve lift. With V-TEC, mere mortal cars can rev like an F-1 engine but still remain tractable in Asian city traffic crawls. The V-TEC gave Honda engines the flexibility to call on a wider range of cam profiles at the prod of the throttle pedal. It was like having 3 to 4 different cam profiles, ready to "deploy" as the situation arouse. Mid range punch was there. So was high rpm singing through the red line. And yet, the engines last as long as anything. Economy was there for sober drivers, while boy racers could indulge their tuned racing engine fantasies. And this was from a stock engine series that was produced by the millions.
The V-TEC revolution
Honda never stopped improving the V-TEC, which is probably on to its 5th generation as the i-V-TEC. Honda's V-TEC gave a new lease of life on Naturally Aspirated engines. Mitsubishi followed suit with its MIVEC and so did Subaru. Meantime, BMW tried its own version by eliminating the throttle and making both the intake and exhaust valves valves behave like electronic throttles. Toyota's VVTi is only similar to the variable valve timing of Suzuki and Mazda. So the V-TEC remained an unassailable performance king.
V-TEC or nothing
Recently, I had the pleasure to drive the latest Sonata with the 2.4-liter Theta engine. This engine uses the latest software to optimize its dual valve timing for intake and exhaust. Mated to a sophisticated 6-speed transmission, it should be able to make up for its lack of a V-TEC. The same can be said for the latest Mazda 6 with a 2.5-liter 16-valve 5-speed. But both were no match to a stock 1999 Honda Accord with a first generation 2.3-liter V-TEC. In both mid range and high range rpm, the Euro 5 engines of the Hyundai and Mazda could not close in on the rear bumper of the Euro 3 Honda. Given an advantage with its older and less choking emissions control, the Accord, despite having just a 4-speed slush-box was not for the overtaking.
And so life goes on with the V-TEC as king. Sure, there are non-V-TEC engines out there that can out-pick up and out-accelerate the latest i-V-TEC. Racing engineer Pacho Blanco, shares with us the disdain against car makers who manipulate the throttle body to give the impression of pick up from a stand still. This misleads the driver into thinking the engine is peppy, only to realize that the mid-range falls flat, hopefully, not when overtaking on a narrow 2-way road. Moreover, this manipulation of the pick up characteristics screws the emissions performance. These car makers are a bit disingenuous because such tricks makes the engine deteriorate from Euro 3 to Euro 2 levels of pollution control.
Honda the honest
Honda prefers to be honest. That's why modern day Cities and Civics may be a bit down on the pick up, but no other engine brand can come close to the way the i-V-TEC engine comes into its own from mid-range punch to high rpm all out power. Even at Euro 5 levels of emission control.
Where to from here?
Perhaps its an engineers vanity not to adopt anything like Honda's cheeky and very effective V-TEC, principally the variability of valve lift. More so with European engineers as they shift to smaller turbos or superchargers or as in the case of VW-Audi group TFSi engines, combining turbos with superchargers with Direct Injection. Direct Injection for gasoline engines, once pioneered by Mitsubishi, did wonders for engine pick up in the same way CRDi or common rail direct injection did wonders to diesel engine performance. It makes turbos and superchargers a natural complement, but such forced induction apparatus works well with V-TEC too. At last, FIAT has introduced its own system of multi-valve adjustability. Called Multi-Air, it has one element that it shares with the Honda V-TEC system: variable valve lift. Despite initial reluctance, the V-TEC revolution is just beginning. With the V-TEC, the reciprocating piston internal combustion engine has a had a new lease on life.