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

Posted by timothy on from the profit-is-a-good-signal dept.

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.

6 of 383 comments (clear)

  1. Cam shafts work without the battery by chromaexcursion · · Score: 3, Insightful

    The fundamental parts of the engine are all mechanical. They work without a battery.
    Resilience to electrical failure is important.

    1. Re:Cam shafts work without the battery by jonnythan · · Score: 4, Insightful

      Like fuel injectors and fuel pumps?

      No modern car engine will run without electricity.

    2. Re:Cam shafts work without the battery by Brandano · · Score: 5, Insightful

      But the failure of a mistimed valve is way more catastrophic than that of a misfiring injector or spark plug. Even if an electrically actuated valve system was to be used in production I'd expect it either to be supported by a backup mechanical system or to be designed never to interfere with the volume occupied by a piston. In the first case the electronic valve would be an additional cost only justified on high performance engines, in the second case it would affect the performance negatively. Perhaps this could work with sleeve valve engines?

    3. Re:Cam shafts work without the battery by jo7hs2 · · Score: 5, Insightful

      Yeah, the idea of something smashing into something else due to a failure is what concerns me. I've already experienced what happens when a camshaft position sensor fails gradually enough that it doesn't trigger a fault in a computer...nasty ignition timing with backfires at high RPM...a Ford Taurus belching fire on the highway...and the idea of parts flying around without protection is why I don't own an interference engine. https://en.wikipedia.org/wiki/...

  2. My Company Had One... by Thelasko · · Score: 3, Insightful

    rumor is the hydraulics used a ton of power. The thing was much less efficient than a traditional cam driven engine. Sure, the valve timing and lift was perfect, but it was otherwise a nightmare.

    Ever break a timing belt on an interference engine? Very bad.

    --
    One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
  3. Useless Change by Anonymous Coward · · Score: 0, Insightful

    I highly doubt it'll give any benefits - and it replaces a proven principle developed over 150 years. Through variable Camshaft Gears modern engines already control the in- and outlet timing for maximum efficiency today. And if you ever changed your own parts on the valves you'd know that it takes tremendous force to depress the valve into the "open" position on larger engines. It probably just isn't worth it to replace the (nearly free) mechanical force a camshaft uses to press them (each valve moving "up" helps depressing the others through its spring-force) with an electromagnet of the same force. It uses large amounts of energy, you can no longer "roll-start" a petrol engine with a drained (or damaged) battery, you have to include power electronics to control the magnets all for (probably) no measurable gain in efficiency whatsoever?