菱-4G92 Mivec Engine (改)

这帖内容是转载的,虽然如此,发此帖的原因是想利用这个帖子来召集所有对mivec engine有所研究心得的人,让大家能在此帖互相讨论和研究改车心得,谢谢..

改4G92发动机175匹

菱-Lancer MR的4G92发动机(Engine)(最早出现在1995年)。1.6L DOHC自然进气配MIVEC可变气门技术,能产生惊人的175匹动力(horsepower)。。  

在购买4G92后需要特别注意清洗机油泵、凸轮轴室附近的机油通路及部件。因为Engine放就了容易使机油流失和凝结,从而导致MIVEC无法正常启动(靠机油控制凸轮轴改变气门动作),如此动力将大打折扣,反成了一台普通的1.6L发动机(4G92一般在4500-5000rpm之间启动MIVEC,所以后段的力量相当利害)。另外4G92是高压缩比Engine,要改它来用,请用好油啊。

1.6L DOHC MIVEC
>改装难度 :轻松
>改装特色 :保留自然进气发动机的顺畅性,又得到类似本田VTEC同样惊人的高转爆发力。

Turbo加MIVEC!
有人把4G93换上4G92的缸盖组成全新的Engine。这样便能在中转(约3200rpm)时享受涡轮增压(Turbo)的推背感(Force Pulling),又能在高转(Higher RPM)(约4500rpm)时享受MIVEC的癫狂,充分利用了两种发动机的“加力武器”,有如开双Turbo发动机一样。

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●动力Power更改配件一览 (有没有人能把文章中里的特殊机件名词翻译成英文啊?谢谢..).
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4G92总线、电脑、仪表
进气风箱及滤清器
NGK火花塞
FDR中至尾段N组赛车排气系统

●底盘Footwork 更改配件一览
CUSCO搅牙避震
后顶吧
前轮双活塞刹车卡钳
17寸合金轮圈
飞劲215/45 R 17轮胎

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下来就和大家分享转自其他网站,但经过修改的好文章..借此希望mivec爱好者能够互相交流..
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1. 原装 4G92 Mivec Racing Sport Edition Engine, 未经过清洗..


2. 经过清洗(overhaul)的引擎,看起来亮多了..


3. 4G92 Mivec Racing Sport Edition Engine 独有的, 中缸(Middle Block)位置有个油冷系统 (红色框内的).


4. 4G92 Mivec Racing Sport Edition Engine 头蕉(Exhaust manifold / Extrator)比普通的4G92要大许多, 是 4-2-1 的.


5. 这个是什么,高人指点下.. (有人说可能是调节汽油和空气的咚咚...)


6. 引擎内腹(英文称呼?)


7. 这就是4G92的核心Core部件, Mivec机构…NA的魅力就在于此…也可以看出Mitsubishi的结构和其他车厂的不同之处, 4G ...


8. Core部件的背部,文章的原发贴者叫它盘头(Head).


9. 中缸活塞(Middle Block Piston)


10. 突轮轴 (Cam)
上图为RS版的,下图为普通版的.



11. 缸头强化(Intake Manifold)



12. HEAD!



13. 组装..组装..



14. 这个是Pulley,原文的作者说用这个东西的原因，主要是RS版的4G92，Low CAM的升程已经和普通版的92差不多高，他很担心低扭时会十分不好，故想尽办法想提高低转时的扭力。, 本地有人有过吗...


15. 这个不用说了吧..原装 Mitsubishi 的 Clutch Cover


16. 完成.. 看上去好像很不错...羡慕..



17. 原文帖主的车的影片..
http://www.56.com/u98/v_MjYyNjUxODM.html

18.??? 没了..希望 mivec 爱好者互相交流下... 不要潜水或灌水啦...拜托...

[ 本帖最后由 菱帅 于 2008-1-22 12:51 PM 编辑 ]

支持支持~~

解释清楚,谢谢.....

多谢分享.

MIVEC (Mitsubishi Innovative Valve timing Electronic Control system)[1] is the brand name of a variable valve timing engine technology developed by Mitsubishi Motors. MIVEC, as with other similar systems, varies the timing, lift and duration[2] of the valves by using two different camshaft profiles. At low speeds, a mild (low-lift) cam lobe provides stable idle, lower emissions and increased torque at lower speeds, while above a fixed engine speed a second set of cam lobes are activated, providing higher lift and duration; therefore a greater quantity of air into the combustion chamber which increases the power and torque output over a broad engine speed range.

From 4B1 engine family onward, MIVEC has fully evolved into a continuous variable valve timing system (dual VVT on intake and exhaust valves). [3] MIVEC incorporated in 3B2, 3A9 and 4A9 engine family continuously varies only the intake valves. Many older implementations only vary the valve timing (the amount of time per engine revolution that the intake port is open) and not the lift.

MIVEC was first introduced in 1992 in their 4G92 powerplant, a 1,597 cc naturally aspirated DOHC 16 valve straight-4.[4] At the time, the first generation of the system was named Mitsubishi Innovative Valve timing and lift Electronic Control.[5] The first cars to use this were the Mitsubishi Mirage hatchback and the Mitsubishi Lancer sedan. While the conventional 4G92 engine provided 145 PS at 7000 rpm,[6] the MIVEC-equipped engine could achieve 175 PS at 7500 rpm.[7] Similar improvements were seen when the technology was applied to the 1994 Mitsubishi FTO, whose top-spec GPX variant had a 6A12 1997 cc DOHC 24 valve V6 with peak power of 200 PS at 7500 rpm.[8] The GR model, whose otherwise identical powerplant was not MIVEC-equipped, produced 170 PS at 7000 rpm by comparison.[9]

Although initially designed to enhance performance, the system has subsequently been developed to improve economy and emissions, and has been introduced across Mitsubishi's range of vehicles, from the i kei car to the high-performance Lancer Evolution sedan.

Operation
Some types of variable valve control systems optimize power and torque by varying valve opening times and/or duration. Some of these valve control systems optimize performance at low and mid-range engine speeds. Others focus on enhancing only high-rpm power. MIVEC system provides both of these benefits by controlling valve timing and lift. The basic operation of the MIVEC system is altering the cam profiles and thus tailoring engine performance in response to driver input.[2]

In essence, MIVEC serves the same function as "swapping cams", something that car racers might do when modifying older-design engines to produce more power. However, such swaps come with a compromise - generally yielding either greater low-end torque or more high-end horsepower, but not both. MIVEC achieves both goals. With MIVEC, the "cam swap" occurs automatically at a fixed engine speed. The cam switch operation is transparent to the driver, who is simply rewarded with a smooth flow of power.[2]

Two distinct cam profiles are used to provide two engine modes: a low-speed mode, consisting of low-lift cam profiles; and a high-speed mode. The low-lift cams and rocker arms - which drive separate intake valves - are positioned on either side of a centrally located high-lift cam. Each of the intake valves is operated by a low-lift cam and rocker arm, while placing a T-lever between them allows the valves to follow the action of the high-lift cam.[2]

At low speeds, The T-lever's wing section floats freely, enabling the low-lift cams to operate the valves. The intake rocker arms contain internal pistons, which are retained by springs in a lowered position while the engine speed is below the MIVEC switchover point, to avoid contacting the high-lift T-shaped levers. At high speeds, hydraulic pressure elevates the hydraulic pistons, causing the T-lever to push against the rocker arm, which in turn makes the high-lift cam operate the valves.[2]

In summary, MIVEC switches to the higher cam profile as engine speed increases, and drops back to the lower cam profile as engine speed decreases. The reduced valve overlap in low-speed mode provides stable idling, while accelerated timing of the intake valve's closing reduces backflow to improve volumetric efficiency, which helps increase engine output as well as reduce lift friction. High-speed mode takes advantage of the pulsating intake effect created by the mode's high lift and retarded timing of intake valve closure. The resulting reduced pumping loss of the larger valve overlap yields higher power output and a reduction in friction. The low- and high-speed modes overlap for a brief period, boosting torque.[2]

In the systems latest generation (4B1 engine family), intake and exhaust cam timing is continuously independently controlled to provide four optimized engine-operating modes:[3]

Under most conditions, to ensure highest fuel efficiency, valve overlap is increased to reduce pumping losses. The exhaust valve opening timing is retarded for higher expansion ratio, enhancing fuel economy.
When maximum power is demanded (high engine speed and load), intake valve closing timing is retarded to synchronize the intake air pulsations for larger air volume.
Under low-speed, high load, MIVEC ensures optimal torque delivery with the intake valve closing timing advanced to ensure sufficient air volume. At the same time, the exhaust valve opening timing is retarded to provide a higher expansion ratio and improved efficiency.
At idle, valve overlap is eliminated to stabilize combustion.

In the early years of developing its MIVEC technology, Mitsubishi also introduced a variant dubbed MIVEC-MD (Modulated Displacement),[10][5] a form of variable displacement. Under a light throttle load, the intake and exhaust valves in two of the cylinders would remain closed, and the reduced pumping losses gave a claimed 10–20 percent improvement in fuel economy. Modulated Displacement was dropped around 1996

很不错的贴 。。

很难得在 Jbtalks 里看到这么有提供质询的楼 。。

支持 。。

自己发完帖,当然要顶自己的帖啦.. (虽然是转发的..呵呵..)

4G92 Mivec 月尾有两粒新的，有没有人要买？

为什么就是没有人回答楼主的疑问。。。我是不会。。不然一定...