are the engines using non cam activated valves e.g. electromagnetically operated valves?

if noit, then why not?

I seem to remember reading about BMW doing some development with different methods of valve actuation and possibly Honda too. I'm not aware of any production engines with alternative technology yet though.

Makes perfect sesne to me provided the reliability, weight and performance criteris can be met. It would free engine designers to look at different shapes and positions for valves and would presumably allow infinitely variable valve timing over the rev range - like vtec/vvc, but better.

A lnog time before it would reach the likes of us though

A friend of mine did a project on this at uni - they got a single cylinder bike engine running with solenoid operated valves. Don't know if it's been looked at by any of the big manufacturers - I'd be very surprised if they aren't working on it though.

Most of the technologies require 24volt sytems, and most OEMs like mine won't swap over to the higher voltage.

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Originally posted by nib1980
Most of the technologies require 24volt sytems, and most OEMs like mine won't swap over to the higher voltage.

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I'd expect to see it in F1 before it got anywhere else. The problem is developing solenoids that are able to actuate against the high cylinder pressures, cycle at the required speed, and still maintain accurate valve position. It'd take some seriously powerful magnets to provide all that, I don't know if the materials are available yet to do so.

What nib said.

Valeo is pioneering such a system.

One of the other benefits that is not widely publicised is the ability to utilise the engine as a braking mechanism with electromagnetic valves this becomes easy.
Brake dust is actually very bad for your health and an environmental problem.

EDITED: I would be surprised to see it on F1 cars due to the weight, and speed implications. 19000+ rpm is a lot more opening and closing per minute than 6000. You may be right though, it would certainly prove its reliability if it worked in that environment.

[Edited on 20/9/06 by clockwork]

The current required to operate them , and the losses experienced are huge. Several companies have played with the idea over the years, but at present the technology is not suffiently developed.

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Originally posted by clockwork

EDITED: I would be surprised to see it on F1 cars due to the weight, and speed implications. 19000+ rpm is a lot more opening and closing per minute than 6000. You may be right though, it would certainly prove its reliability if it worked in that environment.

[Edited on 20/9/06 by clockwork]

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Originally posted by 02GF74
Pretty sure I heard the renaulr had them in an F1 car but they were pneumatically operated.

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2001 Ferrari V10 with pneumatic valve gear

The Suzuki MotoGP bikes have pneumatically operated valves. Not sure how they work though.

Ducati have sued desmodromic valves for lots of years - two followers, where one opens the valve and the other closes it. It reduces valve bounce to an absolute minimum!

I can't understand why rotary valve development seems to have died a death!?!

arggghhhh!!!

Everybody talks about "pneumatically operated valves"

they are NOT pneumatically operated!!

They have pneumatic valve SPRINGS!!!!

This is common to most top level competition engines now, and in VERY basic terms an ECU controls valve spring pressure, minimising it at lower speeds to reduce losses and maximising it at high speeds to prevent bounce. Also removes the problem of natural frequencies.

Didn't the F1 engines still have cams to open the valves? I thought that they were just closed by pneumatics instead of springs

Sorry, added my reply whilst still on page one of the thread! Still, nice to know that I was correct

[Edited on 20/9/06 by Richard Quinn]

yep, exactly correct!

Sorry are we talking about pneumatic or electromagnetic?

If electromagnetic, I'm pretty sure nobody is using them. Though a link would prove me wrong.

From what I understand F1 cars use nitrogen instead of the springs. The valves are cam opened as normal, but use a small piston on the follower for pressurisation as the cam goes past the pressure is released and the air pushes the valve shut acting like a spring. As there is not a perfect seal there is a nitrogen remote cylinder to keep the pressure up.

I think they have some sort of spring/friction damping still to damp the opening and avoid the valve decellerating too fast when it reaches fully open.

Here you go :

http://scarbsf1.com/valves.html

Suzuki also experiemented with rotary valves in their bikes in the 60s but I think that was for 2 strokes

I think also Lotus have been looking at solenoid based valves from some time too.

On top of that Mazda have at least one fruity engine with no inlet valves relying on the turbo pressure to keep the gasses escaping.

[Edited on 20/9/06 by Catpuss]

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Originally posted by Coose
I can't understand why rotary valve development seems to have died a death!?!

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