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DIY : Honda Civic B-Series Engine Oil Pan/Oil Sump Gasket Replacement

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This is critical maintenance issue to handle (if you are first timer), every step to install is critical, the worse case is, your engine oil may dry at the time you drive and overheat or you just lucky to repeat all the step and waste your time and money, I bear all this in my mind, so, I better not to do any single mistake.

DISCLAIMER: I can not say this is the best or safest way to do. I am not
responsible for any thing you damage, or what ever harm you cause to
yourself or others. This is how I did it and it worked for me.

First, need to make sure the leak is REALLY come from oil pan/oil sump or somewhere else, so, after looking around, yes obviously…

1st step, drain out the engine oil…

This is the reason why you need to replace oil drain bolt washer,

To gain more access room, remove the splash shield,

The next step is to remove entire header (I mean before catalyst converter), need to disconnect the oxygen sensor at the first place,

Remove exhaust pipe bracket nut,

Remove exhaust manifold bracket bolt,

Remove nut that tight exhaust pipe (from the header) and catalyst converter,

Remove the header cover and the entire self-locking nut that hold the header, and carefully remove header from your engine…replace the gasket if needed.

I took this chance to cleans the head exhaust side holes from carbon deposit that build-up,

Remove the bracket that connects between engine block and gearbox (optional) to gain more access room, remove flywheel cover.

And then, remove the oil pan/oil sump,

I think, this the source of leak…there are two leaking major factor, 1st the wrecked gasket and 2nd the bending oil pan. My oil pan looks flat and ok.

So, shopping time!

WARNING : The procedure below is a fatal to follow, or you will probably face the never ending leak. Just to remember, this procedure is suitable for Honda B-series engine only and I don’t recommend for other engine type.

This is important step, make sure everything is extremely clean, especially oil pan mate surface and block mate surface, I also clean all the stud, nut and bolt. The cleaner everything is the more you reduce your chances for leaks.

Look extremely closely at the two studs next to the transmission, gasket has 2 metal eyelets inside and lots of times the old ones get left behind on the studs. Remove it.

Put new gasket at the oil pan (don’t apply any liquid gasket at the oil pan), the gasket itself have 2 line that designed to prevent the oil leakage and this is good enough.

Apply liquid gasket (I recommend Hondabond, but my local dealer only have Permatex Ultra Grey RTV) as even bead, centered between the edges of the mating surface (cylinder block side only), just a little bit…I repeat, just a little bit.  Do not install the parts if five minutes or more have elapsed since applying the liquid gasket.

Tighten the nuts finger tight at six points as shown below.

Tighten all the bolts and nuts in two steps torque the bolts and nuts in a criss-cross pattern as shown below, starting from nut 1. Torque: 12 Nm (9 lb-ft), use only small torque wrench, or you can use your six sense (like I do).

Fill the engine oil and drive at the very least 3 or 4 hours after installing oil pan. My recommendation: 12 hours.

– END WARNING-

Install everything back in reverse and enjoy your drive and free from everyday-think-about-oil-pan-leak .

VTEC – The Power of Honda

Posted in My Automotive Life | No Comments »

I found this articles very meaningful and useful, for sharing, all credit belong to : world.honda.com, Source : http://world.honda.com/history/challenge/1989vtecengine/index.html, http://world.honda.com/automobile-technology/VTEC/

VTEC – The Power Of Honda

VTEC (standing for Variable valve Timing and lift Electronic Control) is a system developed by Honda to improve the combustion efficiency of its internal combustion engines throughout the RPM range.

This was the first system of its kind and eventually led to different types of variable valve timing and lift control systems that were later designed by other manufacturers (VVTL-i from Toyota, VarioCam Plus from Porsche, and so on). It was invented by Honda’s chief engine designer Kenichi Nagahiro.

Introduction to VTEC

An elegant, simple mechanism Switching between high and low valve lift using two cam profiles and two rocker arms per cylinder.

The switch is made using hydraulic pressure to push/release the sliding pin, locking/unlocking the middle rocker arm and the other rocker arm.

At low engine speeds, the pin is retracted, disengaging the middle rocker arm. The valves are operated by the two outside, low-profile cams for a low valve lift.

At higher engine speeds, increased hydraulic pressure pushes the pin, engaging the middle rocker arm. The valves are operated by the middle, high profile cam for high valve lift.

VTEC: a deceptively simple mechanism that uses hydraulic pressure to switch between different cam profiles.

In the regular four-stroke automobile engine, the intake and exhaust valves are actuated by lobes on a camshaft. The shape of the lobes determines the timing, lift and duration of each valve. Timing refers to when a valve is opened or closed with respect to the combustion cycle. Lift refers to how much the valve is opened. Duration refers to how long the valve is kept open. Due to the behavior of the gases (air and fuel mixture) before and after combustion, which have physical limitations on their flow, as well as their interaction with the ignition spark, the optimal valve timing, lift and duration settings under low RPM engine operations are very different from those under high RPM. Optimal low RPM valve timing, lift and duration settings would result in insufficient fuel and air at high RPM, thus greatly limiting engine power output. Conversely, optimal high RPM valve timing, lift and duration settings would result in very rough low RPM operation and difficult idling. The ideal engine would have fully variable valve timing, lift and duration, in which the valves would always open at exactly the right point, lift high enough & stay open just the right amount of time for the engine speed in use.

In practice, a fully variable valve timing engine is difficult to design and implement. Attempts have been made, using solenoids to control valves instead of the typical springs-and-cams setup, however these designs have not made it into production automobiles as they are very complicated and costly.

A 4-stroke engine goes through induction, compression, combustion and exhaust strokes to generate power. Before the advent of VTEC, the valves controlling the intake and exhaust strokes were operated according to fixed rules.

If the intake valves were made to open a relatively small amount to privilege drivability at low engine speeds as used in normal driving conditions, the engine would not be allowed to intake enough air at higher engine speeds, sacrificing outright performance. On the other hand, if the intake valves were made to open wide to privilege breathing at higher engine speeds, performance at low engine speeds would be compromised. This is a dilemma that has plagued engines for over a century.

The new approach was to regulate valve operation to optimize performance at all engine speeds: opening the valves a small amount at low engine speeds, opening the valves wider as engine speed increases. That’s the breakthrough we named VTEC.

The opposite approach to variable timing is to produce a camshaft which is better suited to high RPM operation. This approach means that the vehicle will run very poorly at low rpm (where most automobiles spend much of their time) and much better at high RPM. VTEC is the result of an effort to marry high RPM performance with low RPM stability.

Additionally, Japan has a tax on engine displacement, requiring Japanese auto manufacturers to make higher-performing engines with lower displacement. In cars such as the Supra and 300ZX, this was accomplished with a turbocharger. In the case of the RX-7, a wankel rotary engine was used. VTEC serves as yet another method to derive very high specific output from lower displacement motors.

DOHC VTEC
Honda’s VTEC system is a simple method of endowing the engine with multiple camshaft profiles optimized for low and high RPM operations. Instead of one cam lobe actuating each valve, there are two – one optimized for low RPM stability & fuel efficiency, with the other designed to maximize high RPM power output. Switching between the two cam lobes is determined by engine oil pressure, engine temperature, vehicle speed, and engine speed. As engine RPM increases, a locking pin is pushed by oil pressure to bind the high RPM cam follower for operation. From this point on, the valve opens and closes according to the high-speed profile, which opens the valve further and for a longer time. The DOHC VTEC system has high and low RPM cam lobe profiles on both the intake and exhaust valve camshafts.

The VTEC system was originally introduced as a DOHC system in the 1989 Honda Integra sold in Japan, which used a 160 hp (119 kW) variant of the B16A engine. The US market saw the first VTEC system with the introduction of the 1990 Acura NSX, which used a DOHC VTEC V6. DOHC VTEC motors soon appeared in other vehicles, such as the 1992 Acura Integra GS-R.

SOHC VTEC
As popularity and marketing value of the VTEC system grew, Honda applied the system to SOHC engines, which shares a common camshaft for both intake and exhaust valves. The trade-off is that SOHC engines only benefit from the VTEC mechanism on the intake valves. This is because in the SOHC engine, the spark plugs need to be inserted at an angle to clear the camshaft, and in the SOHC motor, the spark plug tubes are situated between the two exhaust valves, making VTEC on the exhaust impossible.

SOHC VTEC-E
Honda’s next version of VTEC, VTEC-E, was used in a slightly different way; instead of optimising performance at high RPMs, it was used to increase efficiency at low RPMs. At low RPMs, one of the two intake valves is only allowed to open a very small amount, increasing the fuel/air atomization in the cylinder and thus allowing a leaner mixture to be used. As the engine’s speed increases, both valves are needed to supply sufficient mixture. A sliding pin, which is pressured by oil, as in the regular VTEC, is used to connect both valves together and allows the full opening of the second valve.

3-Stage VTEC
Honda also introduced a 3-stage VTEC system in select markets, which combines the features of both SOHC VTEC and SOHC VTEC-E. At low speeds, only one intake valve is used. At medium speeds, two are used. At high speeds, the engine switches to a high-speed cam profile as in regular VTEC. Thus, both low-speed economy and high-speed efficiency and power are improved.

i-VTEC
i-VTEC (The i stands for intelligent) introduced continuously variable camshaft phasing on the intake cam of DOHC VTEC engines. The technology first appeared on Honda’s K-series four cylinder engine family in 2001 (2002 in the U.S.). Valve lift and duration are still limited to distinct low and high rpm profiles, but the intake camshaft is now capable of advancing between 25 and 50 degrees (depending upon engine configuration) during operation. Phase changes are implemented by a computer controlled, oil driven adjustable cam gear. Phasing is determined by a combination of engine load and rpm, ranging from fully retarded at idle to maximum advance at full throttle and low rpms. The effect is further optimization of torque output, especially at low and midrange RPMs.

For the K-Series motors there are two different types of i-VTEC systems implemented. The first is for the performance motors like in the RSX Type S or the TSX and the other is for economy motors found in the CR-V or Accord. The performance i-VTEC system is basically the same as the DOHC VTEC system of the B16A’s, both intake and exhaust have 3 cam lobes per cylinder. However the valvetrain has the added benifit of roller rockers and continuously variable intake cam timing. The economy i-VTEC is more like the SOHC VTEC-E in that the intake cam has only two lobes, one very small and one larger, as well as no VTEC on the exhaust cam. The two types of motor are easily distiguishable by the factory rated power output: the performance motors make around 200HP or more in stock form and the economy motors do not make much more than 160HP from the factory.

In 2004, Honda introduced an i-VTEC V6 (an update of the venerable J-series), but in this case, i-VTEC had nothing to do with cam phasing. Instead, i-VTEC referred to Honda’s cylinder deactivation technology which closes the valves on one bank of (3) cylinders during light load and low speed (below 80 mph) operation. The technology was originally introduced to the US on the Honda Odyssey Mini Van, and can now be found on the Honda Accord Hybrid and the 2006 Honda Pilot. An additional version of i-VTEC was introduced on the 2006 Honda Civic’s R-series four cylinder engine. This implementation uses very small valve lifts at low rpm and light loads, in combination with large throttle openings (modulated by a drive-by-wire throttle system), to improve fuel economy by reducing pumping losses.

With the continued introduction of vastly different i-VTEC systems, one may assume that the term is now a catch all for creative valve control technologies from Honda.

AVTEC
Advanced VTEC was announced by Honda in 2006 and seeks to combine the benefits of the i-VTEC system with continuously variable phase control, which is meant to respond to the driver’s power needs independent of engine speed. Honda announced the AVTEC system will allow for 13 percent better fuel economy over i-VTEC and 75 percent lower emissionsthan the 2005 standards. As of early 2010, the AVTEC system still hasn’t been implemented in production vehicles.

Turbocharged VTEC
For 2007 models, Honda’s Acura luxury division announced the RDX crossover SUV which will feature a new turbocharged 2.3 litre inline 4 cylinder i-VTEC engine. While Honda has used turbochargers before (previous examples include the Honda City Turbo and City Turbo II), this is a first for its Acura division.

VTEC in motorcycles
Apart from the Japanese market-only Honda CB400 Super Four Hyper VTEC, introduced in 1999, the first worldwide implementation of VTEC technology in a motorcycle occurred with the introduction of Honda’s VFR800 sportbike in 2002. Similar to the SOHC VTEC-E style, one intake valve remains closed until a threshold of 7000 rpm is reached, then the second valve is opened by an oil-pressure actuated pin. The dwell of the valves remains unchanged, as in the automobile VTEC-E, and little extra power is produced but with a smoothing-out of the torque curve. Critics maintain that VTEC adds little to the VFR experience while increasing the engine’s complexity. Drivability is a concern for some who are wary of the fact that the VTEC may activate in the middle of an aggressive corner, potentially upsetting the stability and throttle response of the bike.

Variable Valve Timing… for Power and Fuel Economy

The structure of Honda’s VTEC engine, the ultimate expression of an original concept.
In order to develop its next generation of engines for the mainstream market, Honda’s NCE (New Concept Engine) program was launched in March 1984. Specific targets identified through the program included high torque in both the low- and high-rpm ranges and dramatic increases in horsepower per liter. The program was a success, resulting in a series that included the DOHC engine found in the 1985 Civic and Integra, and the SOHC center-plug engine in the 1987 City.

Ikuo Kajitani, who was employed in the First Design Dept at Honda’s Tochigi R&D Center, was involved in the development of these four-valve engines. Through his experience in engine design, Kajitani had become convinced that Honda’s next engine should offer a mechanism that could alter the timing of the valves.

“Characteristically,” Kajitani said, “four-valve engines are known as high-revving, high-output machines. And for that reason we knew it would be quite difficult to achieve low-end performance if the engine’s displacement were too small.”

Problems certainly arose during the process of development. A reduction in the valve’s interior angle, attempted in order to increase low-end torque, resulted in a broken timing belt and valve spring as the unit reached the upper range of revolutions. To address the problem, the development staff put in uncounted hours studying how to balance these two critical areas of engine performance. They knew they had already succeeded with their DOHC and SOHC powerplants, but to develop a new unit that would outperform its predecessors they would have to bridge the gap between the low end and the upper limit.

One group already had examined the idea of switchable valve timing. In January 1983, a year before the NCE program began, a research team was formed to study the mechanism as a means of enhancing fuel economy. Even though by the end of 1982 Honda engines were already capable of a world-beating 50 miles per gallon (mpg), there would be an effort to improve.

A possibility was thus identified through the study of a new valve mechanism. Specifically, it was believed that the installation of a new set of cam followers and rocker arms for high-speed operation on the intake and exhaust sides would help, along with the switching of cam hills according to engine speed.This was to be their solution to higher engine efficiency.

This was the so-called “valve stopping + variable valve timing” mechanism employed in the NCE program. As a core technology for Honda’s proposed new line of engines, the mechanism then underwent a program of study and refinement under the careful supervision of Honda’s research staff. And eventually the mechanism evolved into Honda’s VTEC (Variable Valve Timing & Lift Electronic Control System) engine. Launched via the 1989 Integra, this innovative technology surprised the world with a new level of performance from a compact, fuel-efficient engine.

Designing a Dream: A Hundred Horses per Liter

The DOHC/VTEC mechanism with a set of three cam followers and rocker arms on both the intake side and exhaust side. A wide torque band is achieved through the speed-sensitive switching of cam hills.
“Find a new technology to lead the next generation of Honda engines.” This was the directive issued by the top management at Honda R&D, and in response a project was proposed to expand the variable valve-timing approach. Since it had originally been created to improve fuel economy, the engineering staff’s new assignment would be to combine outstanding mileage with impressive output across the entire powerband.

This proposal was approved as a D-development project, and was instituted in November 1986. The objective was to develop a new engine for the 1989 Integra.

Kajitani, serving as LPL of the engine development project, was excited about the new opportunity. He knew that working on VTEC technology would not merely solve many problems he had experienced in development of the DOHC and SOHC engines, but would play a major role in the creation of future powerplant designs.

Kajitani believed the specification for Honda’s new engine-90 horsepower per liter, or 140 in all from a 1.6-liter unit-was not really reflective of the 1990s approach. After all, the DOHC engine already produced 130 horsepower, but the new engine would only have ten more than that. He knew it just was not enough. Then, as if to read Kajitani’s mind, Nobuhiko Kawamoto, then president of Honda R&D made a thoughtful suggestion:

“Why don’t you raise your target to 100 horsepower per liter?” he asked.

It had always been thought that a normally aspirated engine could not be made to produce 100 horsepower per liter. But Kajitani could see in Kawamoto the passionate vision of an engineer, and he felt inspired by such a straightforward proposal. Of course, he knew it would mean 160 horsepower from only 1.6 liters, at a maximum of 8,000 rpm.

“I understand,” Kajitani replied. “We’ll make that our goal.” Though he was by no means certain such a thing could be done, he certainly had the energy to try. Kajitani knew that in order to embark upon a challenging path, they must set their goals high.

“It felt like a dream,” Kajitani recalled. “Conventional engines in those days could only produce 70 or 80 horsepower per liter. But here we were, being asked to increase it all the way to 100 horses. It wasn’t going to be easy.

“An engine becomes subject to a higher load as you increase its rpm,” said Kajitani. “So, we had to keep in mind the quality-assurance target of fifteen years, or 250,000 kilometers, for a mass-production engine. We all wondered how on earth we were going to reach that number while ensuring the required quality of mass production.”

Kajitani, thus, set a goal for the new VTEC Integra engine: 160 horsepower and 8,000 rpm. Regardless of any obstacles they might encounter down the road, this was the goal they would reach.

An Open Invitation to Participate

The two low-speed cam followers and one high-speed cam follower form the basis of VTEC technology.
It was decidedly easier to set the goal than to convey it to the development staff. When Kajitani sat down with his associates and gave them the news, he was immediately swept back by a barrage of questions.

For example, the target 8,000 rpm was almost 20 percent higher than the maximum output of 6,800 rpm achieved by current 1.6-liter DOHC engines. Moreover, the inertial force upon various engine parts would increase by 40 percent. Naturally, the engine would be subject to considerably higher loads due to its increased interior heat. Therefore, to reduce inertial mass under such high revolutions, the weight of each part would have to be reduced. At the same time, it was obvious that doing so would result in lower rigidity, causing problems in durability and reliability. No one knew how to achieve the goal or what approach they should take. A big debate was started within the team as to whether the goal was even reachable.

It was a natural reaction, of course. They were told to develop a dream engine like nothing they had ever seen before. To achieve it, they would have to enter a new realm of technology. “The more you know, the farther you can see,” said Kajitani.

“The team members couldn’t forget their fears, as long as there was the possibility that they might fail.”

Discussions were held day after day for three straight months. One day, Kajitani decided they had had enough of such discussions, and so gathered his team for an announcement.

Though each team member was interested, the team as a whole needed a push before it could accept the challenge and reach for a new level. Kajitani announced his decision to give that push. He knew that timing would be crucial to the direction of such a large group. Accordingly, he gave them ample time to express their opinions. Eventually, the discussions served to align all vectors in a single direction. When Kajitani finally addressed the engineering staff, he was able to do so knowing that each of them had the burning desire to create the world’s best engine.

“I have decided I’m going to try,” he said, speaking to the group of more than 100 engineers. “It’s an important project, but you don’t have to participate if you don’t want to.” No one came forward to say he was leaving the project, for despite the fears and doubts it was the kind of project no engineer could refuse.

Discerning Genuine Technologies

The VTEC engine parts used around the head. Each part was made lighter and more rigid in order to increase output and withstand greater loads at high engine speeds.
It all began in the planning stage, wherein the team identified approximately thirty new mechanism and technologies they would need to introduce in order to secure a stable VTEC system. These included a valve-operating system with a hydraulic timing selector pin, a small hydraulic tappet mechanism built into the rocker arm, and weight-reduction techniques to achieve higher revolutions and output. However, time and resources were limited, and it would be nearly impossible to achieve all of their objectives. As a matter of efficiency, priority items were selected with an emphasis on satisfying the engine’s product requirements. For the items selected, detailed specifications were set and technological feasibilities examined.

During the selection process, the team came across technologies they believed were unnecessary in meeting the target requirements, along with unverifiable technologies which, if found to be flawed, could affect the VTEC mechanism itself. For advice the development team arranged a consultation meeting with members of the evaluation committee, whereupon the development team listed items they had originally wanted to adopt but now wished to cancel.

The discussions produced no results, since both sides refused to give up any ground. Kajitani was not certain which technologies should be used and which should be set aside. He kept asking himself, “Is this technology genuine?” That was exactly what Kawamoto would say.

“When I wasn’t sure whether to introduce a new technology, Mr. Kawamoto would ask me if the technology was genuine. If I could honestly answer ‘Yes,’ he’d say, ‘Okay, then do it.’ When he asked me if it was ‘genuine’ or not, I was confused about what to say. After all, sometimes it’s difficult to tell what’s genuine and what isn’t. Personally, I thought of a technology as genuine if it had been in the market around for ten years, but Mr. Kawamoto had a different definition. Even so, a technology that’s been for around ten years is one that’s accepted by society. In that sense, there shouldn’t be any problem adopting such a technology to all models.”

Several consultation meetings were held, some of them deep into the night, and at last the committee members accepted the development team’s request. Such difficulties were commensurate with the scope of their proposed achievement. The difficulties the team endured through its discussions with the committee helped bring the VTEC engine to life.

Pursuing Excellence Through Trial and Error

The 1996 Civic equipped with the 1.5-liter, three-stage SOHC/VTEC engine.
The start of development meant, of course, that the team would begin facing the first of many anticipated challenges. There was often fear in Kajitani’s mind, as well. “I thought we might not be able to achieve it because the goal was too high,” he said, recalling the many travails of project development.

It was quite difficult, for example, to balance the valve-timing lift against the load placed on the timing belt, which would increase at high engine speeds due to the spring and other factors. Although it was a problem needing a solution in order to achieve the target output, such an answer would not be easy to find. To make matters worse, they found that the low-speed single-valve timing system was not applicable because it had been patented by another company. After examining numerous countermeasures through laborious trial and error, the team decided to change the entire specification surrounding the valve operating system. Subsequently, they introduced the combination valve-timing system after reviewing the valve diameter, lift and port shape, and identifying settings to ensure sufficient output. Further, they created a lightweight driven pulley using high-density, high-strength sintered alloy, and modified its shape for reduced thickness. This resulted in a 10 percent lower moment of inertia. Through these efforts the team satisfied the requirement for timing-belt load while achieving its output objective.

Output across the full rev range was increased by widening the diameter of the intake valve from the conventional DOHC engine from 30 mm to 33 mm. Also, the team adopted valve timing and lift settings that were comparable to Honda racing engines in order to enhance volumetric efficiency. The improved output resulting from that technique actually served to improve performance at high speeds. Additionally, measures were taken to reduce intake resistance. At last, the goal was reached, with a full 160 horsepower at 7,600 rpm and a redline of 8,000.

Low-speed torque, an initial project objective, was obtained by changing the low-speed cam’s setting from the traditional 35 degrees to 20/30 degrees ABDC (after bottom dead-center). This permitted the intake valve to close early, drastically improving the engine’s volumetric efficiency. Since the engine now had higher efficiency at low speeds of operation, a broader torque band could be realized.

The implementation of new materials was certainly a factor in the successful application of these technologies. For example, since the VTEC engine’s three cam followers must be positioned in a single bore, the camshaft offers relatively limited cam width. Therefore, the shaft must be designed to withstand high surface pressures. To achieve this, the team developed a new camshaft of cast steel. The shaft was made of new high-carbon, high-chrome cast steel alloy, which was given a combination of heat and surface treatments. As a result the unit’s extreme rigidity increased its critical surface pressure by as much as 40 percent.

The exhaust valve, too, employed a newly developed material made of a nickel-based, extremely heat-resistant steel combined with molybdenum, titanium, and tungsten. Accordingly, its heat resistance was increased by 30 percent. Moreover, the larger diameter of the valve’s umbrella section and its reduced stem thickness produced a drop in weight of nearly 20 percent. These ideas and effort gradually shaped a reliable VTEC engine.

Applying the Technology to All Honda Models

The V6 3.0-liter DOHC/VTEC engine powering Honda’s flagship NSX sportscar
The VTEC engine had finally revealed its complete performance profile. However, the success of D-development only meant the start of a critical phase. In order to ensure absolute reliability in mass production and introduce the engine to the market with confidence, the team had to guarantee the functions of all mechanisms and parts. In addition to a significant responsibility for product reliability, the team had special expectations regarding the VTEC engine. Said Kajitani, “We all shared the determination to apply these technologies to every Honda model.”

The team’s view of it was that VTEC technology shouldn’t be limited to the Integra alone but further improved it could be adapted to Honda’s future model developments. As such, the initial specification would have to meet customer expectations. In fact, the team had gone through a repeated process of trial and error designed to eliminate all possible problems, however minor they might have been. Actually, at the onset of engine development their greatest concern was the assurance of engine functions. They knew how difficult it would be to guarantee a complex switching mechanism.

For example, the selector pin had a thickness of only 10 mm, so its operation was affected by wear of just several microns. So, in many cases the more delicate the task the more worrisome it was.

“That’s why we so thoroughly carried out our malicious tests,” said Kajitani. “We were very near the point of overdoing it.”

A malicious test is one designed to verify a mechanis-m’s reliability and performance by subjecting it to conditions far in excess of those anticipated during actual vehicle operation. In case of VTEC, numerous tests were repeatedly carried out for all parts, including the timing belt, camshaft, rocker arm and selector pin, to meet the target switching performance of 400,000 events. The team even analyzed the effect of changing loads on the control of low- and high-speed valve timing. Fail-safe(1*) measures were further incorporated in the hydraulics and electrical systems. In this way the development staff not only eliminated its initial fears but achieved a degree of reliability that was well beyond the target value.

Note(1*): Fail-safe feature: An auxiliary device or system is used to ensure continued operation in the event that a system failure occurs.

The Confidence Needed to Innovate
Honda’s new Integra, equipped with the DOHC/VTEC engine, was introduced to the market in April 1989. The VTEC technology drew considerable praise as the world’s first valve mechanism capable of simultaneously changing the valve timing and lift on the intake and exhaust sides. In addition to its impressive output and high-revving energy, the VTEC powerplant boasted superior perform-ance at the low end-including a smooth idle and easy starting-along with better fuel economy. It was truly a “dream engine”-a completely new driving experience for motoring enthusiasts around the globe.

“Everyone of us had pledged to do his utmost to create a world-class engine,” Kajitani said. “We were confident that variable valve-timing technology would be the next big thing. After all, we had overcome the challenges of development and testing because we knew that only our very best effort would establish this technology.

” The DOHC/VTEC engine was subsequently adapted for use in the NSX, Accord and Civic. Following the SOHC/VTEC engine, and then the VTEC-E in 1991, this technology evolved into the three-stage VTEC engine introduced in 1995, which demonstrated an even greater degree of efficiency in output control.

Accordingly, the VTEC powerplant is now a genuine technology in every sense of the term. This is a benefit shared by the entire Honda organization worldwide, thanks to the dedicated efforts of a talented and courageous development staff.