At http://www.pattakon.com a new Continuously Variable Valve Actuation system is presented, with working prototype photos, plots and animations (even stereoscopic ones).
Any engine, racing or normal, can be improved as the torque can be about constant from very low revs to the top allowable revs of the engine.

Comments? Objections?

 

BMW put that on some of there new 3 series cars including the new M3. It's supposed to have the potential for lots of horse power. The only problem is that you can't upgrade cams so your stuck with stock cams.

 

Would you have to got the factory to get some different grinds? I guess this is good if you dont want to upgrade em....

Blaze

 

porsche has been using this system for years

mike

 

Still got pushrods

 

toyota/lexus, porsche, BMW, and TONS of other companies went straight to continuous valve timing control...

Aren't the new rsx's constantly variable???

 

toyota's system isn't contantly variable...VVti is still variable and the new rsx i believe just has increased resolution, not constant tho.

 

the variable one on the lexus is constant... I'm almost positive. well at least the new v8 is and it's still called vvt-i

http://www.autoworld.com/SCcoupes.htm

"VVT-i employs continuously variable intake valve timing control to provide greater engine performance, better fuel economy and reduced emissions over a broad rpm range."

 

i believe you there , i was just talking about the toyota line

mike

 

The new VVA system, is not a continuously variable valve timing system, you misunderstood.
The new system is a continuously variable valve lift system – from zero lift to a maximum lift – which has integrated also the operation of a continuous VVT.
So different thing a VVA and different thing a VVT. The ultimate is to combine both of them.

Toyota’s most advanced system is the VVTLi, first applied on celica, which has just two distinct cam lobes per pair o valves (one mild, one wild) combined to an independent continuous variable valve timing.
Porsche’s VariocamPlus is similar in operation to celica’s VVTLi, as it has two distinct lifts and a continuous VVT system.
Only BMW’s valvetronic has infinite valve lifts of intake valves (and not exhaust valves) and an independent continuous VVT system (Vanos). The new system (compared to valvetronic) can handle both, intake and exhaust valve lifts infinitely, can operate at really high revs, is shorter and lighter, is simple (as it does not need necessarily drive by wire – imagine a motocycle engine with drive by wire – as it does not need an additional VVT system, as the number of parts involved is much lower, etc).

Just do not confuse VVT systems with VVA (variable valve actuation systems). They are quite different.

Thanks

 

The most recent system of Porsche is the VariocamPlus which has two cam lobe profiles per valve (one for 3 mm lift and one for 10 mm lift), coaxial bucket lifters hydraulically activated to select which of the two cam lobe profile activates the valve, and a conventional VVT (variable valve timing system).
So, the most advanced system of Porsche, at present, provides just two step of valve lift combined with a VVT.
Thanks

 

BMW’s valvetronic combined to double vanos (a continuously variable valve timing) is a similar product, not the same.
The new system compared to BMW’s valvetronic is simpler (as it has very few parts, as it needs not drive by wire, as it need not additional variable valve timing system, as it needs not extreme accuracy etc), is more efficient and direct (count the number of interfering joint from cam lobe to valve stem), is much shorter and it is able for really high revs.
The new system solves the problem of “continuous variable valve lift from zero to a maximum with the valve clearance constant” in a pure geometrical way, without compromises.

As regards the cams, even in the prototype – as mentioned in the site – the original single and mild camshaft has been replaced by a pair of wild (and of long duration) camshafts. So, your remark that the camshafts cannot be upgraded is not correct.

Thanks

 

If the 25 mm (from center to center) valve lever seems equivalent to a push rod, OK call it pushrod.
But make me a favor: take a small rod of 31 mm length (25 mm from center to center plus 6 mm for the two spherical ends) with 4 mm diameter into your palm, look at it and say : it is a push rod.
Thanks