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Discussion Starter #1
Hello,
anybody has some idea on the advantages/disadvantages of the ff engine technologies:

Duratec - known to be built for reliability? any other advantages?
iVTEC - more power and economy by spreading tourque in wider RPM range
VVTi - ?

Which is the best Motor technology? Just for my education [:)]
 

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Duratec is the name of the engine. iVTEC and VVTi are technologies on top of the engines. A very common Civic engine is the B16A2 engine. This is the name of the engine, and it happens to have VTEC on it.
 

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To be honest, the Focus version of the Duratec is a watered down version of Mazda’s Duratec. VTEC and VVT-i both represent their (Honda and Toyota) version of Variable Valve Timing, which is not available in the Focus’ version of the Duratec, however it is in the Mazda. Recently, Mazda added VVT to its 2.0L

The Focus Duratec is more reliable than its predecessor, the Zetec. However, it falls short when compared to VTEC and VVT-I, all of which are just names to specialize the engine and its technologies. These engines actually have characteristics, which are usually represented in some grouping of numbers and letters
 

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not much technology in the duratec. unless it has vct, and even then there isn't anything to special to vct or vvt. just a solinoid, oil passages and an different style cam gear. and other than that it is simple algorithims. ie:

cruising - exhaust valves hang open longer to create egr effect
 

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Discussion Starter #5
So it sounds like variable valve timing has a clear advantage? I heard they are more fuel efficient. Is it true and by how much let say same driving condition?

Duratec with VVT sounds good [:)]
 

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nope. and a duratec does not have true vvt.

while the varialbe cam timming adjusts valve timming through cam timming, it cannot change lift

and vvt is for emissions and low torque engines such as hondas
 

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which bottom line the duratec is better than VTEC and VVT-i.... [rofl]
 

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what do you want, an engine that has to have variable cam timming added so you can actually go down the road with all 60lbs/ft of torque with a honduh of [:)][:)][:)][:)][:)][:)]g furey motor, or a motor with torque.

there is no real advantage or disadvantage to fixed cam timming, vct or vvt. vvt and vct have proved extremely reliable, and it eliminates the need for an egr valve

the clear advantage of vvt over vct is that you virtually have unlimited possibilites of what the timming can do, however that is limited to the stock pcm. but it is possible to tweak with tunning software
 

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no maybe he wants IVTEC or VVT-I so he can have a stock 2.0 that runs low 15s stock[driving]
 

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thats one thing that we cant have.
 

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grenada_focus said:
The Focus Duratec is more reliable than its predecessor, the Zetec.
How do we know this?? Aren't there plenty of Contours, Cougars, Mystiques, etc. that are running perfectly well after 10+ years?? I'm not saying you're wrong, just wanna know what prompts you to believe that statement...

Lamar
 

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dont the duratec engines have something with the intake manifold that is a type of "vtec" allowing air to speed up or slow down... i believe i read that in a thread.
 

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gottaride28 said:
dont the duratec engines have something with the intake manifold that is a type of "vtec" allowing air to speed up or slow down... i believe i read that in a thread.
There is nothing on a Duratec that compares to VTEC.

On the intake manifold, there are 2 technologies; VLIM and VTCS. VLIM is Variable Length Intake Manifold, where at around 4000 RPM, the intake manifold switches from long runners to short runners. VTCS is Variable Tumble Control System, where at speeds below 1500 RPM, four flaps deploy to create tumble in the air stream and improve fuel atomization.
 

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it all sounds greek to me
 

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fordblue72 said:
the duratec uses a "short & long" intake manifold. VTEC is controled through the valvetrain
no it doesn't. it uses tumble flaps to atomize fuel below 3,000 rpms
 

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wickedgreyzx3 said:
no it doesn't. it uses tumble flaps to atomize fuel below 3,000 rpms
The 2.3l uses both. There are 2 solenoids on top, one controls the tumble flaps, one controls the runners.
 
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