What good is a vtec motor anyway?


#1

In everyday, plain english, what is the advantage of having the Vtec engine in my econo-box Accord LX? I’ve already read all the technical articles relating to cam/valve timing profiles, etc, etc.



I’ve noticed that this engine performs really well in the 4000-6000 RPM range (only experienced once or twice during emergency acceleration)


#2

Are you making a case that the engines technology does not fit with the quality of the rest of the car?


#3

No im just wondering what the technology does for the car other than make my valve cover look cooler.


#4

The best way to explain it in plain English is that with most cars, you have a normal cam shaft, which allows the valves to open and close at a point in the combustion cycle that maximizes either fuel economy, power, or somewhere in between. With Honda’s VTEC engine, the cam shaft shifts to allow the engine to change the timing of the opening and closing of the valves. In normal operation, the valves open and close in a manner to maximize fuel economy. In conditions where power is demanded, the cam shaft shifts to allow the valves to open and close in a manner to maximize power.

The VTEC engine has other innovations too, but the variable timing achieved by a shifting cam shaft is its most distinguishing feature.

Basically it allows you to get both better fuel economy and more power.

Here is a video that explains the cam shaft features and some others that make this engine unique.


#5

Cool video, does my engine have the 16 valve motor as well ?


#6

I believe it does.


#7

It should be noted that Honda is not the only manufacturer using variable valve timing technology. It’s fairly common these days. Everyone has their own name, or acronym, for it.

I think the fact that your original post refers to your “econo-box” car, but then says the engine “performs really well” pretty much answers your question.


#8

Performance-econobox is not a bad word. Some think it is a good-thing.


#9

Yes, most everybody does variable valve timing. Honda adds variable valve lift, by having two different cam profiles that work under different load conditions. The only other maker with technology like this that I know of is BMW.


#10

In the simplest terms it allows for more power at upper RPM’s when needed with great fuel efficiency in the lower end during the majority of driving.


#11

In 2003 you had to get the Civic EX to get the Vtec motor, and to me it was worth it. Whitey gave a great technical description.

When you rev the motor in 2nd or 3rd gear you can feel a slight “bump” up in power as the valves cam shifts the timing. It allows the motor to have more top end power. If you never get the motor above 4,000 rpm you may never feel this, and you are not going to see any advantage.

When idling and running a lower rpm, below 3,500, the valves are timed to give better torque at lower rpm. This gives the motor a bit more pull at lower rpm than the same motor without Vtec. This feature you benefit from everyday but you’ll not know it without driving the same car with the non Vtec motor. In the end you have better low end power for around town driving, better top end power for passing at expressway speeds, and all without giving up any mpg at all.

At 85K miles my Vtec motor is so smooth and quiet at idle that I can’t tell it is running. With the 5 speed I do crank up the rpm at times and find plenty of power to enter expressways safely. The car is pretty much a sport car with a practical 4 door body. Still love it after all these years and miles.


#12

Ford T’birds from '03 to '05 used variable valves on a V8 motor. It works nice on the T’bird too. I think my Toyota Sequoia might have variable valves, may have to check that out. There are quite a few motors with variable valves now. Honda developed Vtec for motorcycle engines initially, then racing engines, finally regular car motors got the technology. Honda originated the concept and perhaps still does it best.


#13

I know those have variable valve timing, but I didn’t think they had variable lift. I checked, some do (VVTL-i and Valvematic on Toyota (not on any current Toyota, though), VVEL on Infiniti G-37, and BMW’s Valvetronic), but that’s all I could find. The Ford Tbird’s AJ-35 engine only had variable valve timing, as far as I can tell.


#14

In 2003 you had to get the Civic EX to get the Vtec motor…

The Civic Si has been using a VTEC engine since 1988.

For those who are wondering, VTEC stands for “Variable Valve Timing and Lift Electronic Control.”


#15

VVTLEC is too hard to pronounce.


#16

I would say that more cars today have it than don’t. The V8 Mustangs from 05-up have it. Every Honda has it, Every Toyota does, Most GM cars and trucks do, even the pushrod engines. Every Jag, Every Benz and BMW excluding the diesels have it. Every Acura, Every Infinite, Most Fords, including every vehicle with the DOHC 3.5-3.7L and 3.0L Duratec V6s and even some of the 2.3L DOHC 4 cylinders have it. The new Chrysler Hemis have it as well as all vehicles equipped with Chrysler’s 1.8L - 2.3L World Engine".

Variable valve timing is almost universally standard today


#17

Yes, they have variable timing. What most those don’t have is variable lift, which is what the Honda does have. Two different things.