Honda Previews New Engine Lineup: Direct Injection and CVTs Coming

Honda Previews New Engine Lineup: Direct Injection and CVTs Coming

Much has been said about the new Honda Civic receiving a list of early updates in a bid to silence critics while restoring the car’s class-leading fuel economy. This has all but been confirmed, with the Japanese automaker revealing an entire new lineup of engines and transmissions at a press briefing held at the Twin Ring Motegi Racing Circuit on the eve of the Tokyo Motor Show.
In total, Honda unveiled five all-new engines, ranging from a new Kei car 660 cc motor, to a flagship 3.5-liter V6 powertrain. With these engines Honda has said it is committed to being both a leader in fuel economy and engine output.
Engines destined for North America include a new 1.5-liter, 1.8-liter and 2.4-liter 4-cylinder, as well as a 3.5-liter V6. Across the board, all will receive direct-injection technology. The 4-cylinder engines gain a new VTEC arrangement with an Atkinson cycle lower load cam plus extensive friction reduction technologies. The result on a car like the Civic will be a 10 percent improvement in fuel economy, plus a 5 percent increase in power over the current model. The same goes for the 2.4-liter, which one Honda representative told us the new 2012 CR-V just missed out on receiving.
As for the V6 engine, it will replace both the current 3.5-liter and 3.7-liter engines, combining the best technologies of both, including a cylinder deactivation system while gaining direct injection. Honda provided a preliminary, and conservative, estimated power output with 310-hp and 265 lb-ft of torque, with a much stronger torque band.
Of note, all of the engines included a start-stop function, although no decision has been made by Honda as to whether we’ll see this technology in North America.
Apart from the new dual-clutch 7-speed transmission (integrated into a new SH-AW, discussion of automatics at the Honda event was non-existent. Instead, Honda revealed several new CVTs (and yes, they can hear you groaning in Motegi). Of note is a new CVT designed for compact cars, as well as another for mid-size, meaning you should look for CVTs to find their way into cars like the Civic, Accord and CR-V soon. As terrible as all this may sound for Honda owners dreading the thought of a CVT, the good news is what Honda is calling “G-Design Shift”, which was created to help deliver more immediate throttle response. We did have the change to test out the new CVT in a 2.4-liter direct-injection TSX but we can’t tell you about it until the embargo lifts next week. Stay tuned.

New Honda Earth Dreams Technology 1.6L diesel in Civic to deliver CO2 emissions of 95 g/km

New Honda Earth Dreams Technology 1.6L diesel in Civic to deliver CO2 emissions of 95 g/km

 

Honda’s new 1.6-liter i-DTEC engine in the new Civic will deliver CO₂ emissions of 95 g/km, according to Honda Motor Europe’s President, Manabu Nishimae, in his presentation at the Geneva Motor Show. This is a 15-gram drop (13.6%) from the 110 g/km emissions of the enhanced 2.2L i-DTEC introduced in September 2011 at the Frankfurt show. (Earlier post.)
The 1.6-liter i-DTEC offers maximum power output of 118 hp (88 kW) at 4000 rpm, and 300 N·m (221 lb-ft) of torque at 2000 rpm). The new 1.6-liter i-DTEC engine is the first of Honda’s new Earth Dreams Technology engine series (earlier post) to be introduced into Europe. It will be manufactured at Honda’s UK manufacturing facility in Swindon from the end of 2012.

Honda Civic 1.6 i-DTEC Earth Dreams. Click to enlarge.

The application of new high-strength material in the cylinder head has enabled Honda to deliver the world’s lightest aluminium open deck 1.6-liter diesel engine.
By downsizing from the outgoing 2.2L engine and extensively reducing mechanical friction in each section, a friction level equivalent to present gasoline engine models was achieved.
The engine features an optimized thermal management system due to improvements in the cooling system. A compact, high-efficiency turbocharger and weight reduction in the reciprocating sliding section realizes a sporty and nimble ride, according to Honda.
Honda will also renew our entire European engine line-up, with a new engine series called Earth Dreams Technology. With these engines we aim to be Number 1 in fuel economy in each sector within 3 years.

—Manabu Nishimae

Honda Civic Engine Using water as fuel

Honda Civic Using WATER As FUEL Source - Water Gas Hybrid Car Kit - The top video clips of the week are here

Honda Civic Engine Using water as fuel

3-Stage VTEC Engine (July 1995)

3-Stage VTEC Engine (July 1995)

This engine featured optimal intake valve timing and lift across the low-, medium- and high-speed stages, thus achieving ultrahigh fuel efficiency. Drawing on Honda’s accumulated technologies, it represented a major advancement on the original VTEC engine and employed various mechanisms to achieve excellence in fuel efficiency.

VTEC Engines

VTEC (Variable Valve Timing and Lift Electronic Control) is a valvetrain system developed by Honda to improve the volumetric efficiency of a four-stroke internal combustion engine. This system uses two camshaft profiles and electronically selects between the profiles. It was invented by Honda R&D engineer Ikuo Kajitani.[1] It can be said that VTEC, the original Honda variable valve control system, originated from REV (Revolution-modulated valve control) introduced on the CBR400 in 1983 known as HYPER VTEC.[2] VTEC was the first system of its kind, though other variable valve timing and lift control systems have been produced by other manufacturers (MIVEC from Mitsubishi, VVTL-i from Toyota, VarioCam Plus from Porsche, VANOS from BMW, VVL from Nissan, etc).

SOHC VTEC Engines

As popularity and marketing value of the VTEC system grew, Honda applied the system to SOHC (Single Over Head Cam) engines, which shares a common camshaft for both intake and exhaust valves. The trade-off was that Honda's SOHC engines only benefitted from the VTEC mechanism on the intake valves. This is because VTEC requires a third center rocker arm and cam lobe (for each intake and exhaust side), and in the SOHC engine, the spark plugs are situated between the two exhaust rocker arms, leaving no room for the VTEC rocker arm. Additionally, the center lobe on the camshaft can only be utilized by either the intake or the exhaust, limiting the VTEC feature to one side.

However, beginning with the J37A4 3.7L SOHC V6 engine introduced on all 2009 Acura TL SH-AWD models, SOHC VTEC was incorporated for use with intake and exhaust valves. The intake and exhaust rocker shafts contain primary and secondary intake and exhaust rocker arms, respectively. The primary rocker arm contains the VTEC switching piston, while the secondary rocker arm contains the return spring. The term "primary" does not refer to which rocker arm forces the valve down during low-RPM engine operation. Rather, it refers to the rocker arm which contains the VTEC switching piston and receives oil from the rocker shaft.

The primary exhaust rocker arm contacts a low-profile camshaft lobe during low-RPM engine operation. Once VTEC engagement occurs, the oil pressure flowing from the exhaust rocker shaft into the primary exhaust rocker arm forces the VTEC switching piston into the secondary exhaust rocker arm, thus locking both exhaust rocker arms together. The high-profile camshaft lobe which normally contacts the secondary exhaust rocker arm alone during low-RPM engine operation is able to move both exhaust rocker arms together which are locked as a unit.

The secondary intake rocker arm contacts a low-profile camshaft lobe during low-RPM engine operation. Once VTEC engagement occurs, the oil pressure flowing from the intake rocker shaft into the primary intake rocker arm forces the VTEC switching piston into the secondary exhaust rocker arm, thus locking both intake rocker arms together. The high-profile camshaft lobe which normally contacts the primary intake rocker alone during low-RPM engine operation is able to move both intake rocker arms together which are locked as a unit.

The problem which plagued previous SOHC VTEC systems from incorporating VTEC for both the intake and exhaust valves has been resolved on the J37A4 by a novel design of the intake rocker arm. Each exhaust valve on the J37A4 corresponds to one primary and one secondary exhaust rocker arm. Therefore, there are a total of twelve primary exhaust rocker arms and twelve secondary exhaust rocker arms.

However, each secondary intake rocker arm is shaped similar to a "Y" which allows it to contact two intake valves at once. One primary intake rocker arm corresponds to each secondary intake rocker arm. As a result of this design, there are only six primary intake rocker arms and six secondary intake rocker arms.

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; the other designed to maximize high-RPM power output. Switching between the two cam lobes is controlled by the ECU which takes account of engine oil pressure, engine temperature, vehicle speed, engine speed and throttle position. Using these inputs, the ECU is programmed to switch from the low lift to the high lift cam lobes when the conditions mean that engine output will be improved. At the switch point a solenoid is actuated which allows oil pressure from a spool valve to operate a locking pin which binds the high RPM cam follower to the low rpm ones. From this point on, the poppet valve opens and closes according to the high-lift profile, which opens the valve further and for a longer time. The switch-over point is variable, between a minimum and maximum point, and is determined by engine load; the switch back from high to low rpm cams is set to occur at a lower engine speed than the up-switch, to avoid engine is asked to operate continuously at or around the switch-over point.

Introduced as a DOHC system in the 1989 Honda Integra and Civic CRX SiR models sold in Japan and Europe, which used a 160 bhp (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 with 270 hp (200 kW). DOHC VTEC engines soon appeared in other vehicles, such as the 1992 Acura Integra GS-R (B17A 1.7 liter engine). And later in the 1993 Honda Prelude VTEC (H22 2.2 liter engine with 195hp) and Honda Del Sol VTEC (B16 1.6 liter engine). Honda has also continued to develop other varieties and today offers several varieties of VTEC: iVTEC, iVTEC Hybrid and VTEC in the NSX and some Japanese domestic market cars.

VTEC TECHNOLOGY

Honda first introduced the DOHC VTEC mechanism in the US on the 1990 Acura NSX. But a year earlier in 1989, the Japan Domestic Market got the world's first dose of DOHC VTEC in the 1989-1993 generation of the Honda Integra. The 1989 DA6 Honda Integra RSi/XSi used a 160ps variant of the B16A DOHC VTEC engine. Honda enthusiasts would recongnize the B16A engine since it is currently used in the 1999 and 2000 US-spec Civic Si and Canada-spec Civic SiR. However the B16A used in the current Civics is a second version of the original B16A. The main difference is that the newer US-spec B16A has slightly more power at 160hp.

Graph 1 Okay that's enough history. Lets see how DOHC VTEC works. The figure to the right shows a simplified representation of a intake-valve VTEC mechanism (the exhaust mechanisms work similarly). So for each pair of valves, there are three cam lobes. The two on the outside are low RPM lobes and the one in the middle is the high RPM lobe. The two low RPM lobes actuate the two valve rockers, which in turn pushes the valves open. The high RPM lobe actuates a follower, which is shaped like a valve rocker, but doesn't actuate any valves. The figures show the circular section of the cam lobes touching the valve rockers, and the eliptical section pointing away. Thus the valves are closed in this stage.

Graph 2 During low RPM operations, the two outer cam lobes directly actuates the two valve rockers. These low PRM lobes are optimized for smooth operation and low fuel consumption. The high RPM lobe actuates the follower. But since the follower isn't connected to anything, it doesn't cause anything to happen. This procss is illustrated by the figure to the right.

Graph 3 At high RPMs, oil pressure pushes a metal pin through the valve rockers and the follower, effectively binding the three pieces into one. And since the high RPM lobe pushes out further than the low RPM lobes, the two valve rockers now follow the the profile of the high RPM lobe. The high RPM lobe's profile is designed to open the valves open wider, and for a longer duration of time, thus allowing more fuel/air mixture to enter the cylinder. The improved breathing allows the engine to sustain its torque output as RPM rises, thus resulting in higher power output

DOHC VTEC That is basically how VTEC works. The picture to the right is a picture of an actual DOHC VTEC engine. Note that there are two cam shafts, one for the intake valves and one for the exhaust valves. For each pair of valves, notice that there are three cam lobes: two cam lobes on the outside, and one cam lobe in the middle.



As I've said before. The VTEC mechanism is nothing spectacular. DOHC VTEC is the most ambitious of all VTEC varieties in terms of specific output (except for the up coming VTEC-i). Yet as you can see, the implementation is elegantly simple. VTEC is Honda's solution to the design goal of improving engine breathing at high RPMs while retaining smooth and economical operation at low RPMs. DOHC VTEC technology is currently used in the 160HP Civic Si, 170HP Integra GS-R, 195HP Integra Type-R, 200HP Prelude base/Type-SH, 240HP S2000 and the venerable 290HP Acura NSX. And these are just the US-spec cars. Saying that VTEC is a successful design is an understatement.