Camless Internal Combustion and the Digital Age (hackaday.com)

szczys writes: The internal combustion engine is amazing, and it continues to evolve. Carburetors gave way to fuel injection, and a computer now monitors all kinds of sensors to ensure these engines operate at peak efficiency. But there is one thing that has remained largely unchanged: the cam shaft. This is a device responsible for mechanically timing the operation of the cylinders. It's possible to build an engine that uses digitally controlled actuators instead of a camshaft to decide when each cylinder should fire. These exist as prototypes — we have the technology, so why aren't we building with it? The answer is that change is hard, and as with the carburetor it could take an outside force (in that case mandatory efficiency benchmarks) to get automobile manufacturers to wager a bet on new technology.

Comments

meh

[nvm_my_comment]

Inefficient, noisy, polluting, maintenance intensive, expansive, complex, why are we still trying? There's no alternative?

Don't understand engines, eh?

[BitZtream]

TL;DR - Because its a stupid idea and you clearly haven't put more than a fuzzy seconds thought into it. Theres not really any point in doing so.

The first question is: WTF is a digital cam, other than some retarded idea you came up with because OMG DIGITAL DUDE!!@$#!@$. Don't use words you don't understand and don't make any sense at all.

The first statement is: The instant you said the cam shaft controls when the cylinder should fire ... you made it completely clear that you don't know shit about engines since you can't even get basic terminology right. You've lost all credibility already by anyone with a clue.

Now lets get to the meat:

Any changes to the cam shaft are done in order to change the power band of the engine, what RPM range where it produces the desired output power and efficiency. Any change to it just changes the ideal power band, so unless your running across a wide power range, really going all over the place all the time, then this is pointless.

There is ultimately little reason to come up with some electronic gizmo to do this because an engine can simply be built to fit the task at hand. For most engines, the RPM range is very small and constant. Even cars have a relatively small RPM range when in motion thats limited to less than 1000 RPMs difference across the entire power cycle when the transmission is taken into account.

So awesome, you can gain %2 efficiency at the end of the power band in automobiles ... and it'll break 1,000,000 times more often because the existing design is a single solid chunk of metal that sits in the second hottest most stressful part of the engine ... and you want to replace with a bunch of moving bits and magnets.

You'll get more efficiency out of your engine by just using the proper oil than you're going to get out of a highly dynamic cam shaft.

When you exclude cars ... then almost every engine remaining runs at a single given RPM ALL the time, meaning there is absolutely 0 value to a dynamic cam configuration and the net is a negative value due to increased complexity and decreased reliability.

Now go back to making a digital hammer and a digital screwdriver ...