EJ1B18c

No more valve float?
http://www.youtube.com/watch?v=inrBH...eature=related
http://www.decuirenginetechnologies....glessvalve.php

DDTECH

10k rpms no problem now

EdSales

Got to love the 1970's School Health Music.

Back on topic, that system looks very nice, and is going to cost a ****. Wonder if it will ever make its way to Honda Motors?

1.5Slowmatic

intake and exhaust on same side? nifty idea

jlude90

shitty idea, i hate non-crossflow heads.

Doesn't Ducati run a similar system?

Toostinky

I'd hold out for solenoid actuated valves... imagine being able to "tune" your cams to whatever size you want.

ABK

Better yet have infinite vtec just progressively change all the specs.

95skunkedgsr

i dont know if that will ever happin ... when i think of this i think of kinda liek drive by wire ... you know how when you stomp on the gas in drive by wire car there is a slight hesitation befor the it acualy registers ... if that happins with a valve you could count on it kissing the piston

or if the solinoid gets stuck open or something ... to many things that could go wrong

00Red_SiR

fuel injectors are solinoids and how often do they get stuck open or fail? I understand what you're saying and there are problems that need to be worked out but the power, economy, driveability and emissions that could be had with a camless engine using solinoid actuated valves is incredible.

95skunkedgsr

i agree with you but I personaly just belive its a bad idea and i look at injectors complety differnt that kind of a bad comparising becasue injectors dont have to move something with mass as a valve ... not that a valve haves alot of mass , but also what happens if the valve is in its opening event and your motor missfires or detonats wouldnt the force of the the "ping" be devastating to the solinoids? It is a pretty intereasting topic I would like to read more about it. If they could get it to work that would be so badass imagin bein able to control what valve opens when and how much it opens all of our tuning programs would have to be re enginered

95skunkedgsr

as i was working i just thought of how badass this would be imagine never having the risk of blowing a motor up for over reving or miss shifting again .. becuase in theroy the program that is used to run the soloniods could have a fail safe to keep the valves from opening under a misshift (of course the bottom end dosnt count if it cant handle the rpms i guess this fail safe would be useless)... and same for revlimiter just have it so valve dont open anymore at desired rev limit , and as long as injectors arnt squirting fuel it shouldnt be a problem .... The solonoid it self would have to be pretty beefy tho becasue i can see problems when your running 10.1 compression and like 20psi of boost, im not good with math but cyclender preasure would be up there if my logic is correct

89canefighter

motorcycles have been doing this since the start of the 880cc gp bikes. the technology works wonders but it is very expensive!!!!!!!!!

thewind

its called desmodromic valvetrain, and its been around since the late 1800s. it was basically invented to overcome poor spring quality in those days, but later used by race teams to increase the operating range of their engines.

heres good info on it
http://en.wikipedia.org/wiki/Desmodromic

cruizinmax

iTrader: (2)

Right. Ducatis have been doing the "valvespringless" thing for a while. It does work well however they do seem to be very noisy and also require frequent valve adjustments as there is nothing to take up clearance as the valvetrain wears. Clearance=valve doesn't close all the way.

Rotary valves are were it's at. Any downsides to these?

92TypeR

In order of operating speeds, valve motion can be controlled by steel springs (Max speed ~15,000 RPM), Titanium springs (max speed ~17,000 RPM), pneumatic spring (max speed ~20,000+), electro-hydraulic (max speed 20,000+, camless).

Pneumatic Valve Springs have been used in F1 and MotoGP for a couple decades.

A very simple (reliable) mechanical system.



A silly little fact about valve speeds in F1 - At peak engine speeds (18,000 RPM in current configurations) the valve opens and closes 150 times per second.

pogeeboy27

iTrader: (3)

^^^ I do like pneumatic valve systems. Less weight and very reliable. Question though, do these race teams have to pressurize the valves every race?