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Electrically Operated Valves

grigor

By grigor,
in General Automotive Discussion

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grigor Rising Star

grigor

Posted
Posted

Electrically operated valves.

I’ve been waiting for these since I was a kid, and that’s along time ago.

So what’s the hold up? Formula 1 engineers had a toy with the idea and Mercedes actually has an engine running.

The enormous tuning options are only limited by our imagination.

Just a few:

No cam shafts, timing chains, lifters, rockers etc, etc.

Engine starts decompressed, builds oil pressure then the ecu kicks in some cylinders.

Valve lift, duration and timing all adjustable via the ecu.

Vary the engine capacity by partially filling cylinders to offer a smaller capacity for light load, idle situations.

Completely drop off any cylinder at any time, the mind boggles at some crazy firing orders.

Real engine braking, make the Jake brakes on the Kenworths look twice.

With the fanfare of GM’s “new” olloytec engine and Ford strapping a turbo on their twin cam head, all technology at least 10 years old, where are all the lateral thinkers?

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Thunderbolt Rising Star

Thunderbolt

Posted
Posted (edited)

This would just give manufacturers another reason to f*ck car modifiers in the arse. Notice that it is starting to get a lot harder to modify cars these days because of more and more electrically enhanced products?

An example of this was when the XR6 turbo came out. There were/are measures to prevent turning the boost up too much. It is a complicated issue to fix, which most people have got around by engine management computer modifcations.

You can get around these measures by aftermarket development, but as manufactures get more clued up as to how to protect their development, a lot more work needs to be done by the aftermarket companies to catch up. Hense the price of developing products to overwrite the manufactures settings will be passed onto the consumer.

Edited by Thunderbolt
Big Rizza Mentor

Big Rizza

Posted
Posted

Would the gains over a well designed multivalve, variable valve timing, variable valve lift engine make the enormous increase in development costs worthwhile? Imagine how much software development would need to go into programming such a thing?

IBOO57 Explorer

IBOO57

Posted
Posted

Has been and is still being tested but it needs a Power system much greater than 12 volts.

More like a 48 Volt system and the Current draw on the much larger required alternator to keep the system running puts a massive drain on the engine negating the power penefits gained by not direct driving the Valve train from the Crankshaft.

Works in theory but expense and lack of real world practicality will see it delayed until other problems are overcome.

Bass Junky Grand Master

Bass Junky

Posted
Posted

The valves use a solenoid actuation but with much more control than a conventional on off solenoid.

F1 already use pneumatically actuated valves because a normal cam shaft wouldn't be able to keep up as I understand.

The big determining factor is cost.

The bean counters are the ones who run companies these days.

grigor Rising Star

grigor

Posted
  • Author
Posted

Doesn't matter if it's a quasiturbine, rotary, 2-stroke, 4-stroke, they all have a valve or port of some sort and that's one of the first areas that gets modified when you're trying for more power.

Incidentally there are a few patents pending and of course they don't use massive voltages, solenoids etc. Mostly electro/hydraulic and are capable of operating well within the range of conventional engine RPM's.

As for developmental costs, have any of you seen how complicated a sleeve valve is? Check out a Bristol Centaurus.

  • 3 months later...
kimbod Collaborator

kimbod

Posted
Posted
The valves use a solenoid actuation but with much more control than a conventional on off solenoid.

F1 already use pneumatically actuated valves because a normal cam shaft wouldn't be able to keep up as I understand.

The big determining factor is cost.

The bean counters are the ones who run companies these days.

It's not the camshaft that can't keep up, it's the speed at which the valves have to operate that is the problem. They open and close so fast you get valve float. To stop this you have to use stronger valves springs or dual springs. This becomes a game of diminishing returns as revs rise so do spring resistance , sapping power to open and close the stiffer springs ,etc Ducati and earlier Mercedes use Desmodromic valve operation. This system doesn't use valve springs but levers off the camshaft to positively open and close the valves. Pneumatic valves just use air or N2 for springs

  • 2 weeks later...
dontfeelcold Experienced

dontfeelcold

Posted
Posted
Rota whatta whatta?

What are these fandangled things you speak of?

:P

The next BIG step will be rotary valves in the everyday engine. This kind of thing makes camshafts and valves obsolete. Once the bugs are ironed out that is.

just google "rotary valve engines" for some good examples.

ebola Proficient

ebola

Posted
Posted

rotary valves on one of these.

(just trying to up the ante. Don't care much for counter rotation, but more power al all rpm + a higher rev limit...)

and although the how stuff works article implies it, I don't think there has been a working prototype of an internal combustion quasiturbine engine.

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