51–58 of 58 posts
Ironically, the same advances in power electronics, cheap high-speed computers, and electromechanical actuation that made individual valve control possible also enabled efficient electric drive motors that made valves in cars a non-problem.
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4 electric motors on wheels is extremely simpler than 2 motors, mechanical differentials and couplings. I actually helped a mechanical engineer to create a simulator for car dynamics in software. Today's cars are over engineered mechanically in order to support and resist the forces and torques from the motor to the wheels. When you put the motors in wheel you basically reduce the required rigidity and the weight of…
" 4 electric motors on wheels is extremely simpler than 2 motors, mechanical differentials and couplings." Why not 2 on one axle? Do you really need all wheel drive?
It seems in tech just when the incumbents seem like they will lose to the upstart they achieve a breakthrough and the inevitable is delayed for a few more years. Combine this breakthrough with what Michigan State is doing in gas powered engines and battery powered cars dominance is delayed for at least another decade. http://www.wkar.org/post/reworking-michigan-msu-develops-lig...
Well this quote from the original article struck me as odd: > Nobody's ever done variable valve timing on the exhausts, so the benefits are less well understood. BMW's been doing this for twenty years. Honda's been at it for over thirty years. On. The. Exhaust. Valves.
They have replaced a pure mechanical linkage with a motor in each valve. A typical 4 cylinder engine will now need sixteen extra motors to run it. While I like the idea of controlling the timing of each valve interdependently for the other, I am not for the additional electronics in the engine.
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Wouldnt the test just need to apply to all modes? If its a matter of automatically tuning through a series of conditions then its reasonable that those could be documented and tested by the facility / standards body.
Efficiency testing of appliances (eg. Dishwashers) only tests the default mode. That's why all dishwashers have a mode which takes 4 hours and does a lousy job. It's the mode that only uses 3 drips of water and a sip of electricity.
I've never had a problem with our one with it's 2.5hr eco mode, when running overnight (which is 90% of our loads). If we need a quick load during the day, we'll use the 40min cycle. Either way the wash quality seems the same.
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> environmental laws would be much harder to practically enforce with this as you could run virtually any engine anemic enough to get though the emissions tests lol Changing a cam (or cams) in most engines isn't all that difficult. Even without a camshaft you'll still be heavily limited by the shape and size of the combustion chamber and the geometry of the valves. You simply won't be neutering the engine that much.
Changing a camshaft in a classic car is huge pain that requires specialist equipment for setting the timing etc. and getting it wrong can destroy the engine. It's more than possible in a home setting but most home mechanics I know wouldn't touch them. I'm sure it's a lot more complicated on a modern car.
That's overstating the case quite a bit. There are plenty of engines where you don't need special tools.
> I'm sure it's a lot more complicated on a modern car.
Wait. You were talking about older engines? Then, no. You're absolutely wrong. Swapping out cams on most older engines is a piece of cake. Pretty much anything without variable valve timing will be super duper easy. Pushrod motors are especially easy. There are some exceptions, of course, like the DeLorean's V6 (the cams slide out of the head so you generally won't have room to pull them out without pulling the head).
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I would think that could help EVs, as it would be cheaper (in weight and dollars) to add a gas powered range extender to EVs with smaller batteries. I'd rather have an 80 mile EV with a range extender than a very expensive heavy 400 mile EV.
That’s probably one of the least interesting applications, really. We’re already quite good at optimizing engines for a narrow RPM/power range.
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Efficiency testing of appliances (eg. Dishwashers) only tests the default mode. That's why all dishwashers have a mode which takes 4 hours and does a lousy job. It's the mode that only uses 3 drips of water and a sip of electricity.
Do you have a link to any resource which talks about what the best way to use it? Everything easily searched seems to be how to get your dishwasher to run at its most efficient. I've never had a problem with our one with it's 2.5hr eco mode, when running overnight (which is 90% of our loads). If we need a quick load during the day, we'll use the 40min cycle. Either way the wash quality seems the same.
I would put eco mode as 'passable', but you have to remember to scrape off the plates well beforehand, rince especially gungy stuff (like porridge), and to probably do a bit of hand drying of items afterwards.
One the other hand, the 'intensive' mode only uses 50% more electricity, takes a quarter of the time, leaves the plates clean and dry every time, and uses a hotter wash temperature which I suspect is better at killing pathogens, and doesn't need any pre-rinsing or plate scraping beforehand. It's a no-brainer in my mind.