variable valve engine comparo

[orly_andico]

*m2,

thanks for the explanation. that clears up the stuff i'd heard that i-VTEC had less specific power output than DOHC VTEC, but at the same time has better economy and emissions.

does this also mean that even i-VTEC is an intake-only solution? and it doesn't have variable lift? kung ganun eh medyo stone age nga! and really doesn't justify the "i-VTEC is the shitz" attitude.

[mazdamazda]

Yup... i-VTEC is only applied for the intake valves only. Some VVT applications are applied to both intake & exhaust valves (like the VVTL-i).

Btw, it does have variable lift.

[parakitoJDM]

*m2,


does this also mean that even i-VTEC is an intake-only solution? and it doesn't have variable lift? kung ganun eh medyo stone age nga! and really doesn't justify the "i-VTEC is the shitz" attitude.

>>i-VTEC is an intake-only solution? currently yes. like what MZx2 said its for the Cam Phasing only - think real time adjustable CAM Gears! with upto 50deg. of adjustability.

>>stone age? i think u mis-understand. some mfg. even don't have it its pretty state of the art if u ask me.

>> variable lift? i think ur talking about varying Valve lift. Honda has it too. for the K20A3 (CRV, Civic in PH, Accord) this is implemented on the Intake side only. for the K20A2 exhaust side also gets it thats why it can crank out over 200horses fm. 2li of displacement. no other mfg. of NA engine can match that. but wait a few more years, Honda is coming up with even better VTEC engine, i heard something around 11% better fuel effi compared with the K20 series engines....

[niky]

Some manufacturers still don't use McPherson struts in the rear, or DOHC engines... but that doesn't make them state of the art.

Not many manufacturers can match 200hp from 2 liters, but Nissan and Toyota get similar power from their variable cam engines. Nissan's SR20VE is rated at 197 ps (same as the K20) and Toyota has 180+ ps from their 1.8 liter engine. Of course, this isn't to mention BMW's 340++ hp from their 3.2 liter engine, but that's too expensive to consider here.

[ferdine]

what i've heard (but i'm no expert) is that i-VTEC is actually inferior to the older VTEC in terms of performance, it'sreally more geared for economy.

although i don't see why people get all worked up about VTEC in general. VTEC is primitive technology! having only a few discrete cam profiles. Porsche Variocam and BMW VANOS are both far more sophisticated.

or maybe Honda fanboys are just.. Honda fanboys.

He-he-he-he... of course I'm a honda fanboy. My dad used to own a levin and big bro had a starlet for weekend races. I know they were the finest during their time. When i got a 94 civic and fitted it with a b16, it can still outran even the latest altisis I can find in hightways. How much more I think with the gen 8 and the soon type R gen 8 civic.
I'm just practical especially in the PHils. we've got only two popular vvt's technology to choose from Toyota and Honda. I do feel that Honda has the edge for people who are buying the gen 8 and and planning to tinker with their motors as the car ages. Mas richer ang resources sa i-vtec/vtec if you want to play with your engines. Widespread pa ang support sa Honda community through multitude of forums. Just my opinion.

From wikipedia...

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.

[squala]

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.

:evillaugh :laughbounce:

[basti08]

bakit hindi dinala ang mga engines na yan dito?

ang gagaling ng Japs when it comes to extracting power from NA engines.

[mazdamazda]

How much more I think with the gen 8 and the soon type R gen 8 civic.

There's already a Euro Type-R FD Civic. It is still using the old K20 197-hp engine.

we've got only two popular vvt's technology to choose from Toyota and Honda.

Err.. almost ALL car manufacturers / resellers here in the Philippines has a vehicle that is VVT equipped. Mitsu have MIVEC, Mazda has SVT, etc.

The world doesn't revolve around Toyota and Honda. :lol:

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.

Errr... the i-VTEC V6 is not about "valve control". It's about it having a multi-displacement system (which Chrysler pioneered).

it can crank out over 200horses fm. 2li of displacement. no other mfg. of NA engine can match that

Mazda RX-8... 1.3L... 238hp
Toyota Corolla Sport... 1.8L... 180hp
Lotus Exige... 1.8L... 190hp
BMW M3... 3.2L... 340hp
BMW M5... 5.0L... 500hp

[ferdine]

There's already a Euro Type-R FD Civic. It is still using the old K20 197-hp engine.

This is the reason why the "old" k20 is very nice to mod in the long run. You say 197-hp so it matches the A2. Not bad for a 2liter concept car. However K20A1 would be my ideal choice.


[/QUOTE]
Err.. almost ALL car manufacturers / resellers here in the Philippines has a vehicle that is VVT equipped. Mitsu have MIVEC, Mazda has SVT, etc.

The world doesn't revolve around Toyota and Honda. :lol:[/QUOTE]

He-he-he-he-he. See my word "popular". Everbody knows Mitsu and Mazda are just johnny-come-latelys in our market when it comes to VVT tech. And so who made the real headway? Lols:trampoline:

[ferdine]

This is the reason why the "old" k20 is very nice to mod in the long run. You say 197-hp so it matches the A2. Not bad for a 2liter concept car. However K20A1 would be my ideal choice.

Should have been K20A which can deliver much higher.

[ferdine]

Mitsu have MIVEC, Mazda has SVT, etc.

The world doesn't revolve around Toyota and Honda. :lol:

Here is wikipedias entry of Mazda'z SVT:

S-VT
From Wikipedia, the free encyclopedia
Jump to: navigation, search

S-VT, or Sequential Valve Timing, is an automobile variable valve timing technology developed by Mazda. S-VT varies the timing of the intake valves by using hydraulic pressure to rotate the camshaft. S-VT was introduced in 1998 on the ZL-DE engine and is used in the B-, Z-, and J-families of engines.



And here is MIVEC's:

MIVEC
From Wikipedia, the free encyclopedia
Jump to: navigation, search

Mitsubishi Innovative Valve-timing-and-lift Electronic Control system (MIVEC) is an automobile variable valve timing technology developed by Mitsubishi Motors. MIVEC varies the lift of valves by using two different camshaft profiles. It is similar to Honda's VTEC system, but differs from it in the fact that the MIVEC system activates at a lower RPM and has a slightly more conservative cam grind, allowing the transition to appear more subtle at the cost of higher RPM performance. A more limited MIVEC system in the Lancer Evolution controls only valve timing, not lift.

MIVEC technology has been incorporated into the "World Engine", an engine co-developed by Mitsubishi, DaimlerChrysler and Hyundai as the Global Engine Manufacturing Alliance.

And here is a snapshot of VTEC's:

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.


================================================== =======

So that means VTEC's timeline in "mass market" started as early as 1989 and Mazda followed nine years earlier. No mention of MIVEC's entering the mass market so I have no idea. So who really got the headstart in technology offered to the public then? I don't belittle Mazda's RX 8 but we are talking about reciprocating motors here not rotary.

[mazdamazda]

So that means VTEC's timeline in "mass market" started as early as 1989 and Mazda followed nine years earlier. No mention of MIVEC's entering the mass market so I have no idea.

Still relying solely of wikipedia? :lol:

FYI. MIVEC was launched in the early 90s.

And oh, GM pioneered VVT technoloy and Nissan was first one to sell VVT engines (1987 AFAIK).

So who really got the headstart in technology offered to the public then? I don't belittle Mazda's RX 8 but we are talking about reciprocating motors here not rotary.

Technology? Then?

The Mazda GTX sold in the late 80s had a 220hp engine. Honda Integra had 160hp? W-O-W! :charing:

Heck... the Fairlady had 150hp engine already in the 1970s.

:lol:

[orly_andico]

*m2, you can't dissuade the honda fanboys.

although i think the Mazda GTX is not an NA engine.

according to our "canonical" source Wikipedia, the first VVT technology came out in 1975, courtesy of GM. And the Nissan VG30 in 1986.

[mazdamazda]

Orly... yup... turbo yung GTX. just pointing out that "technology" per se is not just the realm of Honda.

[alwayz_yummy]

while sa research ko, napansin ko hindi talaga honda ang piooner sa variable valve tech. either renault/nissan nga...

and sheet comparison, b16a is only rated at 160ps, 4age 20v 170ps, while yung sr16ve 175ps...dont know yung MIVEC 6a10 and 11..MIVEC4g92 ata is 1800...

for me,ha, ang boy racers will always say b16 is da best...

[orly_andico]

ang alam ko nga the first mass-market engine to break 100hp/L was the eagle talon tsi (it's actually some mitsubishi) with a 4g63 engine. don't know kung turbo yun.

it could be argued that Mazda is actually the most innovative engine manufacturer, with their Wankel rotaries and the Miller-cycle KJ-ZEM in the Millennia.

i'm sure most honda fanboys don't even know what a Miller-cycle engine is.

[alwayz_yummy]

yup, agreee ako sa wankel-rotary engine. diba twin turbo yun? nasolve na ata ng mazda ang consuption probs dun sa rx7s nila.....im not a honda fan, pero di familliar ang miller-cycle may much common name po ba to?

[orly_andico]

miller cycle (as opposed to the usual otto cycle gasoline engine) is a modification where the intake valves are held open during the compression stroke. this reduces pumping losses and increases engine efficiency, at the expense of reduced displacement (due to some intake air getting pushed out again).

the KJ-ZEM is based on a 3.0L V6 but only displaces 2.3L due to the loss of displacement. however it produces the power of the 3.0L V6 with the fuel consumption of a 2.3L.

the cycle is called "Miller cycle" if there is a roots-type supercharger on the intake to make up for the lost air. if there is no supercharger it's called an Atkinson-cycle. the Prius has an Atkinson-cycle gasoline engine.

the main use is really to make the system more fuel-efficient.

[alwayz_yummy]

di lang pala ko familliar sa name, pero discussed na name yan sa ICE(internal combustion engine) subject namin...so miller's difference is may supercharger, otherwise atkinson pala un..

[ferdine]

Still relying solely of wikipedia? :lol:

FYI. MIVEC was launched in the early 90s.

:

Here to be exact:
1992

Pajeros finish first, second and third in the overall category of the Paris-Cape town rally.
The "Galant", "Eterna" and "Emeraude" are launched.
The first generation of the "Lancer Evolution" is launched.
The "Debonair" is launched.
INVECS 4-wheel multi-link suspension
4G92 MIVEC engine
Distance Warning System, Passenger airbag
Football Club, Mitsubishi Motors Corporation is established

And oh, GM pioneered VVT technoloy and Nissan was first one to sell VVT engines (1987 AFAIK).
:

Nissan did of course but on a bigger displacement engine:

In 1986 Nissan developed their own form of VVT with the VG30DE{TT) engine for their Mid-4 Concept. Nissan chose to focus their NVCS(Or Nissan Valve-Timing Control System) mainly at low and medium speed torque production because the vast majority of the time, engine RPMs will not be at extremely high speeds. The NVCS system can produce both a smooth idle, and high amounts of low and medium speed torque. Although it can help a little at the top-end also, the main focus of the system is low and medium range torque production. The VG30DE engine was first used in the 300ZX (Z31) 300ZR model in 1987, being the first production car to use VVT technology.

VG30DETT
The 3.0 L (2960 cc) VG30DETT produces 280 hp and 283 ft.lbf when mated with a 4 speed automatic transmission. When used with a 5spd manual transmission, it was rated at 300hp and 283tq. It featured twin T25 turbochargers, twin intercoolers and variable valve timing.

It is used in the following vehicles:

1990–1996 Nissan 300ZX Twin Turbo
1990–1999 Nissan Fairlady Z Twin Turbo

So comparing a VG30DETT to the first integra sold commercially is like comparing an orange to a kalamansi.

Technology? Then?

The Mazda GTX sold in the late 80s had a 220hp engine. Honda Integra had 160hp? W-O-W! :charing:
:

And from answers.com about the Mazda GTX:

The JDM GTX model featured all wheel drive and a turbocharged 1.8 L BP engine. In the U.S. it came with a 1.6L turbo, with the AWD. In 1992, the rare GT-R version was added (ALSO JDM), featuring a number of performance enhancements over the GTX model. These included a stronger gearbox, sodium filled valve stems, an aggressive front bumper and bonnet vents, an up-graded turbo. It is difficult to find a Familia GTR that has not been thrashed to death by a low budget rally team.

This could be the reason why

Heck... the Fairlady had 150hp engine already in the 1970s.
:lol:

Never heard about fairlady. Hindi pa ako isinilang non.

At least masasabi ko lang na Honda popolarized it in mass market and it becomes a like a tradition. Just like my friend asking another friend, "Pare ano ba yong MIVEC? Sagot naman ng isa kong kaibigan,, ano yan. VTEC ng Mitsu.
Para ba gang, Ale, pabili ng Colgate, pero Close-Up naman ang binigay.