I just come up with this, while I was bored

[gr3k0sLaV]

EVVT : Electronic Variable Valve Timing

Now I dont know if this has been thought of yep, I seriously think it has though. I was bored at lame but well paying telemarketing job, when I started thinking about cars and engines. And I thought, well why not completely re do the valve timing.

Now take note, I am vERY VERY new to cars. What I know, I have learnt pretty quickly in about 3 months. When I started out, I didn't even know how a turbo worked or what the cam did.

Now lets look at the A20 , it has 12 valves, 2 for intake, 1 for exhaust for each cylinder. And as we all should know, the camshaft turns, which pushes the valves, opening, closing, etc, etc. The timing of the camshaft is controlled by the timing belt which it linked to the crankshaft (am I right?)

Now my EVVT design would involve scrapping the cam, and having each individual valve controlled by electric motors, which would be controlled by the onboard computer. The computer would use sensors to detect timing, which would obviously be used to set the vales, opening and closing them. The computer would have sensors which would monitor air, fuel ratios, speeds, compression, ignition sparks...and would use all this data to have control over valve timing. The ignition systems and all would all be linked into one unified engine control unit.

Now with this system, you can have much tighter and finer control of all engine related matters. And all that.

However problems with this system that I could see, is that more can go wrong. Reliability of individual motors can play a role. If the computer suffers a fault, it could result in catrasrophe with your valves and pistons colliding.

[dosh8er]

You are correct sir! All of what you said is true. Yes, I believe Mercedes or BMW is using or is testing the EVVT right now. Everything is going to the little silicon wafers, damn it, why cant they leave some things alone?!?

You're right, drive your car into a pond, your car is toast. A computer goes out, you're screwed. It will take a few years (I'd say decades) for computers to become, 1) Cheaper, and 2) failproof. Granted mechanical systems aren't perfect now, but computers will take a lot of engineering to make them work as long as my 1989 accord has. (and will!)

[gr3k0sLaV]

Funny thing is I just thought this up out of the blue, ive never heard of anything like it before.


If a motor or the computer fails, a possible fail-safe would be the valves to automically spring back to protect them and the pistons...however ermmm dangerous levels of pressure can build up...a solution could be to have an emergency release valve that could activate in this sort of situation.

It'd be sweet driving a car with EVVT.

Actually I wonder how much it would cost for someone to have something like this built for their 3rd gen....newer Honda's got VTEC.....we get EVVT...sounds kinda lame...

maybe EVTEK .... Electronic Valve Timing EK

[accordlx]

This technology has been around for about 10 years. And yes, they did scrap the camshaft in this application. The way that this application works is to use 2 very stong electro magnets per valve. One to open the valve and one to close the valve. The whole assembly is spring loaded on either side of the valve. The idle position of the valves is open. That means that you can start the thing literally by hand because there is no compression when the car is not running.

The problem with this application is that there are rev limitations with this type of application. The magnets will not react fast enough to facilitate a higher revving engine. ( Say above 4000 rpms.) The obvious application would be to mate this technology to diesel truck motors since they are very touquey but don't rev very high. The application sounds great for varying your valve timing but unfortunately, it is still very new.

[carotman]

yup like accordlx said, the problem is the rev speed. Maybe with supraconductors, it would work... but since those things only exist at near absolute 0 temperature, it would be impossible to mate them to an engine.

maybe with big turbo diesel engines.

But then again... what would be the gains for that with a low revving engine, the camshaft is already best suited fo the application..

It's a great idea tough that's being worked on. I'm sure that in a couple of years, that will work, but then again, we may be driving electric cars.....

[PhydeauX]

I know its not really the same idea, but toyotas vvt system adjust the valve timeing. It was their answer to vtec, though not nearly as successful. Its basicaly just a computer controled adjustable cam gear.

andy