Has anyone seen this, know anything about it?
http://www.decuirenginetechnologies....glessvalve.php

 

I haven't kept up, but I know Ducatti used a dual lobe desmodromic setup. Very interesting, as that is the first pushrod style i've seen.

 

The only question that matters is : How much $$$

 

Don't forget http://www.coatesengine.com/

 

LOTS of info here...
http://www.google.com/search?q=desmo...e7&rlz=1I7ADBR

 

here is the question....on the pushrod...what makes the rocker arms go back down?

 

It's like a crank, rod and piston system... in this case the piston is the valve.

 

wow no kidding, but here is the deal.

the spring is also what pushes the valve and the rocker arm back to the normal position as well as keeping the lifter on the cam and the pushrod in the lifter pocket by keeping pressure on the rocker arm. so what pushes this back to its normal position?

 

F1 engines have been using pneumatic controlled valves since the early 90's.

 

do these engines use that? if not then that still doesnt explain how they return

 

The european car makers are using a soleniod mounted on top of the valve to open and close the valves. Makes for infinate "cam" timing and duration. Also less rotating mass. DOD is a breeze when you can just crack open the exhaust valve and shut off the fuel and spark.

 

From what I saw in the video the lobe has a grove machined into the side and a tab sets in that grove. As the lobe rotates the tab follow in the track converting orbital rotation into linear movement in the vlavetrain.

 

that is on the overhead cam engine...its easy to see that one

im talking about the pushrods

 

No, he was talking about the pushrod setup. The groove is in the SIDE of the lobe and an arm on the SIDE of the pushrod sits inside of that groove. Basically it's a track that the pushrod arm follows since the cam lobe holds it in place on both sides of the groove.

Think of it like a modern 2D (back and forth, up and down) roller coaster. The steel roller coaster track is the arm on the pushrod and the coaster wheels (on top and bottom of the track) are the groove in the cam lobe. The roller coaster cart cannot deviate either up or down from the track, and that's why they advertise that it eliminates valve float.

Hopefully someone with much more valvetrain experience can give a more thorough discussion on valve float with current technology. It seems much less of an issue than in previous times.

Any proof of this? I haven't kept up completely, but I am unaware of any actually in production.

 

The Coates design is very interesting, but has had a lot of trouble from what I have read.

For awesome digital valve actuation technology: www.sturmanindustries.com

 

one of those designs had a backlash spring, and im no expert but that would make tension to pull it back i think those would wear out faster then up an down motion of push rods

 

wow thats crazy!

 

yeah, like roadrage said, do you have proof? I know from inside GM they were experimenting with some solenoid stuff, but the technology really doesn't exist yet for todays 100k mile warranty world. And I've never heard a thing about any europeans doing this. Also, they don't have DOD...

I'm calling BS.

 

there have been lots of people trying to develop camless engines. lotus has done a few i think..

i think penumatic springs would be the best bet to start with. they are pretty well tested. its just getting them and packaging them.

electronic vavle actuation would be the best solution. i think Lotus again have tried to do this. however you require 72+volt electronics and it would require a major rethink on automotive electronics.

def intresting times though.

Chris.

 

We did the "camless" AURA system in 1994, installed this on a Ford Ranger, dyno tested.

Lance, BTW "Eddie" is my friend