How long until we get rid of the camshaft?

[sendler]

How long before we are finally able to get rid of the cam shaft and put the infinite possibilities of computer control into our valve timing with electro magnetic lift? With direct injection and stratified charge, we could then also tend to eliminate the throttle plate.

[gone-ot]

...I've wondered about that too, for years.

...if they ever migrate up from 12VDC electrical system to 48VDC as they proposed awhile ago, there's a darn good chance that direct electrical control of valve lift & duration could be 100% under computer control...unfortunately, it takes lots of CURRENT to make inertia "change" positions quickly, hence the need for higher VOLTAGE source.

[tjts1]

You'll never get rid of the cam because it will always be cheaper, more efficient and more reliable than stuffing magnetic coils in a hot vibrating environment. Throttleless gasoline engines have been around for years.

http://www.youtube.com/watch?v=B82dRiYdCYs

http://www.youtube.com/watch?v=zW8rub-yuZQ

[Ladogaboy]

In terms of reliability, magnetic properties can be affected by the engine heat, so that is something else to take into consideration.

[Peter7307]

Sendler, sadly it may well take a long long time.

OHC and 4 valve / cylinder were around at the turn of the last century (ie 1900's or so) and look how long they took to become more or less standard.

Will technology drive cars or will the demands of the car makers drive technology?

I personally think car makers will adapt when they have absolutely no other options...and even then it will be a tantrum session to get it all to happen.

Peter.

[JRMichler]

Originally Posted by tjts1

You'll never get rid of the cam because it will always be cheaper, more efficient and more reliable than stuffing magnetic coils in a hot vibrating environment.

I would not say never, but trying to pull a valve almost a half inch using an electromagnet is a real challenge. Doing it at the speeds necessary is beyond available materials.

I designed an electromagnet once to pull 1600 lbs over a quarter inch air gap. It needed over 200 volts at 50 amps to drive it.

[Rokeby]

I guess hydralics are out of the running... too slow/complicated?

[Ladogaboy]

I think the biggest problem is that no one wants to put the energy into such a radical change for what is, ultimately, a dying technology.

[Everett]

As soon as it's cheaper to do it differently.

[JRMichler]

Electromagnets and hydraulics are much more complex and expensive than some bumps on a shaft. Also camshafts have much higher mechanical efficiency.

Dual cams with dual VVT have much of the theoretical efficiency benefits of fully programmable valve timing.