alright I can't quite get a real explanation of what the Ecotec means and VVT means. Its sad i'm a manager of a parts store but cant find anyone who really knows. Even the parts manager at the chevy house told me, "Well, I really cant answer that right now, but I will get back to you." its been two months. Any help?

 

Ecotec is the name of GM's line of 4 cylinder world engines. Kinda like Vortec.

The VVT is Variable Valve Timing. After a certain rpm while accelerating selenoids change the duration of the intake and exhaust valves.

 

Ecotec is the family of GM's current 4-cylinder motors found in the HHR, Cobalt, Ion, G5, Aveo, Sky, Solstice, Astra, and various other small cars. It's really just a name.

VVT Is Variable Valve Timing. I'm not sure as to how it works, or the benefits of it, but i'm sure others will be able to help you out.

 

Ecotec is a family of motors as has been stated. But it's more than that. I remember getting one of the first GM Press Releases about the motor. Apparently it means "Economy Technology." I don't know about that though since I get better gas milage with 40# injectors and a correct injector constant than GM EVER gave me with the stock 24# injectors and their tuning.

VVT for GM is a copy of Toyota's Variable Valve Timing technology. In some cases you might see a -i after it. That stands for "Intelligent." The computer is set up to know when to change the timing and does so on its own, and is unadjustable without getting into the ECU and the control crap. The computer adjusts the cam timing under certain conditions, to provide more power or more fuel economy.

Hope that helps.

 

thanks. I appreciated.

 

http://en.wikipedia.org/wiki/VVT
http://en.wikipedia.org/wiki/GM_Family_II_engine#Ecotec

 

Alfa Romeo was the first modern twin cam engine to have variable valve timing in the mid/late '80's. I had 2 Alfa Romeo spiders with VVT, although it wasn't called that then.

The advantage is the ability to have a mild cam timing at low RPM, which increases economy and (more importantly to the manufacturer) reduces emissions. Also remember that a "wilder" cam is much less efficient and, therefore, produces more emissions at lower engine speeds (it really doesn't start to work until higher RPM - this is called "comming on cam").

On my old Alfa, if I manually engaged the VVT at idle by jumpering the solenoid to check operation, the engine had that characteristic loping idle of a race engine. It really was pretty wildly cammed for the street. But with the cam timing retarded by the VVT, it idled smooth and quiet and was doscile at low to mid RPM.

 

Yes Alfa was one of the first to have it, but GM's setup is almost an exact copy of Toyota's. They have worked together on a few things and that was one of the results. Along with vehicles like the Toyota Cavalier in the mid-late 90s and early 00s and the Pontiac Vibe/Toyota Matrix. Keep an eye out for others too, as I know I have missed a few and more are coming.

 

toyota 20v 4A-GEs had it as well, i don't know if they were before the alfa (toyota did invent the concept in the 70s on race cars AFAIK)... but they were the first to do it on the mass scale.

 

Just read through this...can never know enough about this stuff

I know Ferrari(sp?) used/uses a type of VVT, only its wi/o solenoids

 

most modern engines are designed with VVT in mind. most of which useing one of two types.

the honda vtec system- basically, an entirely second set of wild cam lobes come into play

toyota VVT- basically, the cam changes timing or lift as needed.

the solinoid systems are still somewhat based on the VVT, just uses that to control the cam rather than oil.

 

You should check out the BMW's Valvetronic. http://en.wikipedia.org/wiki/Valvetronic

 

how could i forget.... but i've always thought it was needlessly complex.

 

vtec includes a form of vvt

 

The NUMI plant in California was, I believe, their first joint manufacturing venture. Yes, Toyota and GM have licensing agreements in place.

According to Wikipedia: "General Motors patented the first variable valve timing and lift or smart valve system in September of 1975. GM was interested in throttling the intake valves in order to reduce emissions. This was done by minimizing the amount of lift at low load to keep the intake velocity higher, thereby atomizing the intake charge. GM encountered problems running at very low lift, and abandoned the project.

Fiat had employed the first functional variable valve timing system, including variable lift. Developed by Giovanni Torazza in the 1970s, the system used hydraulic pressure to vary the fulcrum of the cam followers. The hydraulic pressure changed according to engine speed and intake pressure. The typical opening variation was 37%.

Alfa Romeo was the first manufacturer who used variable valve timing system in production cars. Model year 1980 Alfa Romeo Spider 2.0 L had VVT in Spica fuel injected cars in USA."

I don't know if this is totally accurate, but the fact that GM held the first patent and Toyota produced some of the first modern production VVT systems, this seems right.

-J-