Electronic Control - Valves?

[kstar]

I've read some stuff on electronically controlled/actuated valves, and was wondering how you folks feel about the technology.

I think many here appreciate EFI and EI, and contrarily I also understand the old school love of MFI and carbs - I previously owned a hot 3.2 MFI motor.

But wouldn't it be cool to dial in "cam profiles" via electronic valve actuators the same way one can now dial in fuel delivery or spark control? Besides, cams are heavy and add weight at the rear.

I understand that many other factors determine the best cam profile for a specific motor, but it seems to me that electronically actuated valves would allow endless tweaking potential within the parameters of a specific engine design.

Thoughts? Potential weaknesses?

BR,

Kurt

[RoninLB]

Originally posted by kurtstarnes
endless tweaking potential

Thoughts? Potential weaknesses?

the big processor mfg have just started selling 64-bit processors.
I don't think the present valve actuating computers are good enough.

so an in-cabin dial-in torque curve, gas milage, mountain rds, desets, etc.
combined with a JPI EGT & CHT computer would be real cool.

JW could figure the install if he had the computer and valve actuating system handed to him.

[beepbeep]

Originally posted by RoninLB
the big processor mfg have just started selling 64-bit processors.
I don't think the present valve actuating computers are good enough.

so an in-cabin dial-in torque curve, gas milage, mountain rds, desets, etc.
combined with a JPI EGT & CHT computer would be real cool.

JW could figure the install if he had the computer and valve actuating system handed to him.

BMW tried this. It's not computing horsepower that is limiting factor...it's:

1. Amount of electrical power needed to actuate valves quick enough (12V isn't up to this)
2. Heavy solenoids needed
3. Risk of head/valve collision in case computer looses sync

New BMW's have valvetronic system that uses variable valve lift and does completly away with throttle plate. It also has variable valve times (in certain range).

While completly electronic actuators would give you infinitew control over opening times, it has it's inherent bad sides that negate the benefits, at least for now. One malfunctioned coil would send valve into the piston.

My personal belief is that we will never see completly electric valve actuation but probably some sort of electro-mechanic control like BMW's solution. Also, I would like someone (GM?) to take SAAB's SVC idea of variable compression ratio one step further.

Variable compression, valve timing and lift would produce some very efficient and strong motors.

[kstar]

Thanks for your insight guys.

The thought of a virtual electronic cam with electronic valve actuators got my brain excited. I started to imagine a "virtual crankshaft" consisting of computer controlled, electronic piston actuators.

I know these technologies are probably years away, but they are interesting concepts.

IMO, there will be less mechanical and more electronic aspects of the old internal combustion engine.

The idea of electronically actuated valves and pistons would "open to door" to radical and novel engine designs that could conveivably produce more power more efficiently in a more compact and light package.

Here's an interesting article from MIT on a proposal that would support a wide adoption of a new power standard (42v) among automakers:
http://web.mit.edu/newsoffice/tt/1998/oct07/cars.html

BR,

Kurt