Valvetrain RIP

[BigMike]

I have always wanted to redesign the valve train in piston-rod engines because I know it requires a LOT of energy to work the valve train, an energy requirement that increases exponentially with increased RPM.

I had read somewhere that F1 engines use a pneumatic system to operate their valves. Is this true? I've never seen anything on the subject. But I once read that they use air pressure to control both the valve lift and duration. Screw VVTL-i and i-VTEC, this blows them out of the water. Infinite adjustability with NO drag or parasitic losses to the engine (except for that air compressor you have to run lol) You can have instant valve closures and instant valve openings, something camshafts and followers can't achieve due to extremely high contact pressure. You can have lower lift and duration at lower engines, and adjust it infinitely as needed for any power band at any rpm. No more timing belts, no timing chains, man that would be SA-WEEEET!


Well just now I came across this: http://www.dynenco.net/valve_files/valve.htm

Have you guys ever heard of a Desmodromic valve train? This is really interesting to me!! The link above says that Ducati motorcycles have employed this style of valves.



I think this is AWESOME because you can have the same typical belt- or chain-driven valve train just like we have now, but without the huge parasitic loss of valve springs! Think about how much energy can be saved by not having to waste it with valve springs!!!

[Sirdeuce]

Go to billzilla.com on the pnuemo system, he has a description of the setup. The Ducati setup is great, but I hear the maintenance is a BITCH. I always thought a system with an ultra lightweight valve operated by a sloenoid would be infinately adjustable, but uber expensive. The barrel valve was a great idea, but was very hard to seal for more than a few hours. My favorite valvetrain to date though is the BMW. I don't remember exactly the engineeing behind it, but it eliminated the need for a throttle altogether by controlling the relationship between the cam and rocker arm. In a nutshell, at idle you get a minimal lift and duration, and at full throttle the rocker transmits the entire cam to the valve. The system works by changing the position of the rocker(I think) by placing the fulcrum on an eccentric giving a movement of the rocker center. Something like that anyway. Yes it is used in the production cars. Look at the straight 6 in the 3 series of the last decade and the Z4.

[BigMike]

I looked around his site and I can't find his pneumatic system.

We should make an electric solenoid system on a lawn mower and see if we can get it to work

That BMW system sounds pretty cool, I am gonna do some research on it-

You know what gets me is that in order to get a lot of power out of a small normally aspirated engine, we need to rev the engine to the moon. But what does this require? Strong valve springs to prevent valve float. But what do the stronger valve springs do? They create more power loss that increases more and more when you rev it high, which is exactly what we are trying to do, rev it high.

Imagine having the valve train powered by some other means. I bet you'd recover 25% of your power! who knows!

[Sirdeuce]

Well, how about designing a standoff mount for the cams and design a roller system for the AGE head? That'll reduce friction and valve lift won't be restricted.

[BigMike]

Well, how about designing a standoff mount for the cams and design a roller system for the AGE head? That'll reduce friction and valve lift won't be restricted.

I'm confused

[Sirdeuce]

Try looking on this page.www.billzilla.org/engother.htm Scroll down.

[Sirdeuce]

Check this bugger out! I'm sure you'll like it!coatesengine.com/technology.html

[Sirdeuce]

The BMW system I was mentuining before is the Valvetronic system. Here is a youtube video.
www.youtube.com/watch?v=rEELtXVTymU

[Sirdeuce]

Now for some pornographic reading material! Fiat has an electro-hydraulic valve train! PDF file
www.keohps.com/imagine/artigos/flyers/aplicacoes/automotiva/comando%20de%20valvulas.pdf 

[BigMike]

[BigMike]

I'm super busy at work so can't look at these much right now. I'll read everything after my big exam tomorrow morning (cuz i'll be cramming all night today after work!)

This is super awesome man. We gotta design a cylinder head for the 4A using this design

http://coatesengine.com/rotary_motor.swf http://coatesengine.com/poppet-motor.swf

[Sirdeuce]

This'n is a better Bimmer vid
www.youtube.com/watch?v=zW8rub-yuZQ

http://www.youtube.com/v/zW8rub-yuZQ?fs=1&hl=en_US&rel=0

[Sirdeuce]

And just for the hell of it!!
www.youtube.com/watch?v=BPdm51QwZEw

http://www.youtube.com/v/BPdm51QwZEw?fs=1&hl=en_US&rel=0

[BigMike]

Check this out,

Have you ever heard of cams that have a staggered lift for each valve pair?

Source: http://www.pdm-racing.com/products/cam_corner.html

NEW - Tri-Flow Cams

What if someone could make a performance camshaft that could make better power at HIGH-RPM with a minimum low - rpm torque loss, without the use of a variable lift cam system? Colt Cams has managed to do just this for virtually ANY multi-valve engine. By staggering the opening times of the two intake lobes, they have created a swirl in the system. The principle behind this design is to open the intake valves progressively. Opening one valve first allows the fuel to travel across the chamber at a greater velocity due to the smaller venturi action, it then helps pull in the second charge at a faster rate.

This gives the equivalent to the secondaries opening up in a carburetor. In turn, with the larger cam, the engine has better vacuum at idle since there is less overlap, throttle response is greatly increased, and turbocharged vehicles have noticed less lag and faster spool up time. Geoff's theories on the "Tri-flow" have been proven time and time again, on many different engines. The testing has proven the theory, and now it is time to let the world see the results.

Interesting..........................

[Sirdeuce]

Yes I have heard of that. Always thought it would work real good with a TViS system. Improving swirl effect? You could do just as good a job with swirl through portwork and combustion chamber shape. If you want to do it right though, take advantage of the 8 ports of the TViS setup, an divide the ports all the way to the valve. Increase the size of the secondary port, and shorten it. The primary should remain long with a slightly tapered bore to maintain a high velocity intake charge. Then you have tuned for two different operating ranges in the engine. Inject all the fuel into the primay inlet tract, or use 8 injectors. Imagine the tuning capabilities. Then run a timing adjustable cam gear.VVTViSi!!