electro magnetic valves
Turbo Mini Forums

Yes I know this is a bit futuristic and may sound like ramblings (it is too:)). But I guess it theoritically (sp?) could help the 5 port injection troubles . I learned about this in mech. eng. combustion engine class last year(for master engineers). The theory is that the valves will be controlled much like an injector does now. And electro magnetic (or something similar) gadget that control the opening and closing of valves. It has been and is still currently under testing for OEM engines. I have sources telling me that this is working on engines, but is still not sold on production cars as its not a stable enough system yet. Valves could instantly go to full lift, and instantly close. I guess this potensially could eliminate the charge robbing issues, and we would not need a secondary trigger anymore

If anyone have the know how to make this work, it would sure be interesting to try on a test engine. I guess there should be room under the rocker cover in our engines.

Edited by miniminor63 on 25th Sep, 2007.

Dont some ducatti bikes have a similar system ? Perhaps it is hydrulic or something

they have some kind of system that makes it impossible to get valve float on them at least.

Ducatis use a system like a fork that the cam throws open and shut its fairly simple.
Allan

http://www.rabdunn.co.uk/

Google desmodromic with regard to the Ducati set up.
Regards
Dave

okay, so definately not the thing I am talking about.

I believe it is referred to as a camless engine.

That may also be a name for it. Our prof. only talked about it as electro magnetic controlled valve system or the like. I really like the idea to be honest, imagine "programming" your own cam design:)

sounds too good to be true, are there any downsides to instant full lift?

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

Apart from valves hitting pistons?
Regards
dave

You would probably be able to have gradual lift by adjusting voltage gradually. the theory is sound but knowing little about engines i can't say for sure. It could work and you could actually set up a very simple test by modifing a dizzy and a few other bits. It would be very very crude but i think it could work. however this is very roughly thought out in my head. i could set up a test rig rather quickly but would it actually be worth it?

Edit: after a little more thought there alot of factors to take in to consideration. including the materials that the valves and the cylinder head would be made from.

Edited by minimole on 25th Sep, 2007.

i was thinking more of will it interfere with flow at all?

ive always thought penny on a stick valves were a shit idea anyway, as even when theyre open, theyre still there! but cant think of a better so mustnt grumble :)

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

I suppose you could do some sort of sliding valve. but again automotive engineer i am not.

This was done in the '70s on a twin cam 8 valve engine. The theory being infinately variable valve timing and lift would give peak torque over a broad rpm range. It will become mainstream I think once it proves itself reliable.

i think at some point nearly everything has been tried and penny on a stick valves have stood the test of time, maybe due to cheapness, but who knows?

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

Every day is a school day ...........

How fast and how expensive ...... the same question...

Jay I think you are spot on with the VVT,
I can't see the benefit on a 5 port mini with regards to charge robbing, well maybe a bit in as much as you could design the ultimate scatter timing but I don't think you would solve the port/charge robbing issue completely.
Regards
Dave

I hate to burst the bubble guys but the amount of force required to give a good seal with a valve seat of the diameter we use at the cylinder pressures we have (still low compared to a diesel) is quite a bit. This needs a fair amount of force to overcome the springs and an electronic actuator capable of producing the goods is going to be fairly sizable and need a fair bit of juice to drive it. This is before you think of the actuation times.

F1 engines use / have used a pneumatic / hydraulic system which overcomes some of these issues and allows them to rev as high as is required with fully variable valve timing. These systems also can do away with the springs by using the system to hold the valves closed and reduce pressure (easier than raising it) to open the valves.


You may be supprised to learn that the first systems on the public highway are likely to be in large trucks!!!!

The reason for this is simple, they have pneumatic / hydraulic systems all over the vehicles already which can power the system.

They also don't rev highly so the actuation / recovery times are easier to deal with.

It is very interesting but you'd have to be super determined to adapt anything along these lines into something that could be used on an A series in the near future.

Edited by RogerM on 25th Sep, 2007.

Every day is a school day ...........

How fast and how expensive ...... the same question...

Free length minus fitted length multipied by spring rate = seat pressure.
Seat pressure is not a lot
Not trying to be argumentative but sums is sums
Regards
dave

I do believe some muscle car v8s from america use a "camless" system.
Stevieturbo might know what one.

Back once again like a renegade master

danboy, you are correct in what you say but to a relatively small elctormechanical linear actuator it's a fair bit. Maybe my original post didn't really convey what I was trying to say very well. Was half watching TV as I typed.

Remember it has to be able to hold it open at full lift too. That is part of the reason why most people are favouring the pnuematic / hydraulic "spring" as the loading doesn't increase much with travel as the actuation is via changing the volumn which can be near zero increase in load over the range of travel.

Edited by RogerM on 25th Sep, 2007.

Every day is a school day ...........

How fast and how expensive ...... the same question...

http://www.camcontec.com/

bistable valve stuff, somethign to do with rover when they existed tho cant remember the ins and outs.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

yeah true, the curtain area will exceed the valve area after 'x' lift, but the valve stem is still going to be right bang in the middle of the flow...

its just not perfect is what im getting at, but i guess theyre simple and cheap and do the job satisfactorily

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

i have heard about such a system for R&D engines. electromagnetic . not hydrolic. currently the power needed for such a system would be fully impractical. and even it it would work in a car it would be mostly of use to economy engines with low rpm apparently.

That sir, is not rust, it is the progressive mass reduction system

http://aseriesmodifications.wordpress.com/