I am fairly certain Williams has been using pneumatic actuated valves on their F1 cars for the past couple years.

(still looking for a good link to post )

 

Don't know if this is true, but I had heard the patent expired, and that is why Toyota and Mazda could pursue similar technology as Honda's VTEC.

http://pages.sbcglobal.net/celica/history.htm

"Aiming squarely for the top of the Integra line, Toyota turns to Yamaha to produce an engine that outperforms the Honda version in every way. The Honda patent for variable valve timing (VTEC) expires and Toyota is now allowed to introduce its version variable valve timing in the form of VVTl-i (Variable Valve Timing with lift and intelligence). A technology which is superior to Honda's VTEC Toyota and Yamaha introduce this new technology in the Celica with the 2ZZ-GE engine. In a factory built engine Toyota nearly matches Honda's hand assembled, port and polished Integra Type-R, and does away clearly dominates Honda's stock output in the GS-R (160HP)...clearly an accomplishment. "

In either case, I still think the other companies are "working" out there systems, and in theory they are supposed to be better but so far that doesn't seem the case.

 

Found a good explanation of a "3 stage" VTEC.

Still unclear if this is what is implemented in the S2k.

http://autozine.kyul.net/technical_school/.../vvt_2.htm#VTEC

 

I think this is the I-VTEC patent.

http://patft.uspto.gov/netacgi/nph-Parser?...=Honda+AND+VTEC

It hurts my head to read patents. How I ever got through a class on IP law is beyond me.

 

Everyone is free to design their own Variable timing and lift system, but the are not allowed to use Honda's "sliding pin in the rock arm" method. This is what the patent is on. Just like the TV analogy: everyone uses an electron gun fired at a phospor coated screen, but the trinatron patent allows Sony to place all three guns in one housing for more acurate beam control.

Toyota slides a "tab" under a section of the rocker arm to effectively move from one cam to the other, and Porsche has a neat system that is pretty difficult to discribe, but seems pretty simple.

The three stage VTEC is a JDM technology that seems to be tuned for emissions control and fuel economy and not horsepower. Honda also has a version of VTEC that only opens one of the valves to promote more swirl in the conbustion chamber.

The S2000 has the same basic 3 lobe, 2 stage VTEC that debuted on the NSX back in 1990. I like to think of it as the "last hurrah" for the original system before i-VTEC takes over.

 

Hmm, maybe we can look to an even higher horsepower i-VTEC to combat the new Z04?

While we're at it Honda, can you make it a 2.2 litre?

 

The 2003 Accord 4 cylinder will see about a 10hp increase to 160hp with i-VTEC. If we see i-VTEC in the S2000 this next year, it may be because of one of 2 things. All i-VTEC engines rotate clockwise just like the F20C and i-VTEC might be easy to add. Or maybe Honda plans to keep the S2000 around longer then 4 yrs.

Look at what Honda did back in the 60s with their little roadsters. Honda's first roadster was built back in the early 60's. It was the S360, 33hp at 9,000 RPMs, next came the S500 44hp at 9,500 RPMs, next came the S600 57hp at 8,500 RPMs, and finally the S800 with its 70hp at 8,000 RPMs. The S800 was built to compete against the English roadsters of that day.

2004 will be a very interesting year for us !

 

Is I-VTEC better then VTEC then? I heard it was harder to tune a I-VTEC engin

 

Yes !! i-VTEC adds VTC for Variable Timing Control. VTC controls the intake camshaft and allows the valve opening overlap between the intake and exhaust valves to be continuously varied in response to the demands placed on the engine. The relationship between the intake and exhaust timing can be varied by as much as 25 degrees either positive or negative. VTC allows for a further refinement to the power delivery characteristics of VTEC, resulting in improvements of the mid-range power band ( more torque ). The intake valves now face the front of the car (in the case of the RSX and Si) and the engine rotates clockwise. That is a big change from prior generations of front wheel drive VTECs. As I said in the above post, our engine also rotates clockwise and it would be a perfect candidate for i-VTEC. So i-VTEC gives us 4 areas of improvement : 1) fuel economy 2) boost in the mid-range power curve 3) small increase in hp 4) improved emissions. Honda has stated that all of their engines will be i-VTEC in the near future( by 2005 ). They want the improved fuel economy and also to stay ahead of the EPA regulations with the improved emissions.

Haven't heard anything about it being harder to tune and I don't know why it would be.

 

Anyone interested in variable valve timing/lift technology should check out the way Ferrari does it. Apparently they use cam lobes that are extruded in such a way that so that the profile gets more aggressive as you move to one side of the lobe and a hydraulic system pushes the entire cam to one side of the head as the engine revs faster. VERY cool, it just seamlessly pulls like mad, all the way to the redline.

Later,
Zack