Comments by "SeanBZA" (@SeanBZA) on "Engineering Explained" channel.

To be fair to Rolls, they want that engine to be as quiet as possible, and to last at least 10 years without needing an overhaul, while the Ferrari is likely to not make the distance, and in general will not be a daily use car like the Rolls. Thus run the engine in a lower stress region, but have the turbo small to maker it accelerate fast off the mark, giving the impression desired of "effortless power", the exact opposite of the Ferrari, which is meant to be heard.
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@EngineeringExplained Not charging while warm could easily be fixed in firmware, simply turn on a cooling fan, charge at a very low rate till the battery is cool, or just not charge if hot till it cools down, and then keep the charge rate low till the battery is either full, the temperature is low or if you have as part of the charger a timer that allows you to choose a departure time that it should reach for full charge. That would also allow off peak power use, and improve battery life. Active cooling however does mean that you use power to do so, out of the battery bank, IIRC this translates on a Tesla to 1% per day at worst ambient to keep the battery conditioned, not so good if it is low charge anyway.
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But luckily it broke at idle, and only bent 4 valves. Just before it had been at freeway speed, and there it would have turned all the valves, pistons and camshaft into metal confetti. Belt was just past the change interval by less than 1000km.
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@ThePedro8161 Most diesel trains however here also have pantograph pick up assemblies on the roof, so they can use overhead lines for power where available. That way the rairoad saves on expensive fuel use on the final sections of lines, where you use electric power and have no urban pollution problems then. Most of the trackway here in South Africa is not electric, aside from main lines and the commuter train lines, and the trains are limited in most cases to 120kph, though they can go a little faster, but there are lots of speed limited sections around towns and where the rail lines go through passes, due to older track and clearances.
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Thing is mechanical slide on rod is almost always going to win for reliability, speed of operation and power required to operate it. Solenoid operated valves are at their weakest force at beginning of stroke, which is precisely where pressure holding the valve closed will be at it's highest. As well fast operation means high current, and thus a lot of heat, in an already very hot area, making electrical failure very likely very fast. Connectors at that temperature and oil splash are not cheap either, for reliable high current flow, and are going to become very brittle very fast. Imagine having to change 4 actuators and wiring harness, per cylinder, every 50 000 miles as a "service part", because they will fail some time soon after that, killing an expensive engine controller as well.
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@MrGonzonator The losses are to a first approximation constant, so the heavier the load the more power output, and thus the ratio that these losses contribute per kilowatt are less. IC engines are most efficient at a pretty high RPM, but unfortunately they rarely spend much time in this regime, unless you have a hybrid powertrain or a CVT that tries to keep engine RPM constant, where you can have a lot of design optimisation that makes for a very efficient engine over a narrow range, but abysmal performance out of it. Most common on 2 stroke engines with a tuned exhaust, that has a very narrow power band, with impressive output, but a relatively poor performance outside that spot. If your engine is going to spend all the time either off, or at peak power, it can be very efficient as power source, though hard to use for a variable load like driving, but for power generation exceeding good, provided you always have a near full load on it.
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Still got to clear those way oversize calipers and discs. Got to love Alfa who decided they wanted 19inch discs on a car, but 15 inch rims, so put them inboard like most sensible people. Not great for CV joint life though, but much lower unsprung mass made it a lot more responsive.
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ss you could say it was run till the last strand broke, by design.
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Otherwise known as the built in smoke screen maker.
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@hondaguy9153 ROI will suck with that, and in general most industrial electrolysis plants do not respond well to rapid changes in control, they all will have very bad transient response, and you will not get a good product out efficiently. Extreme case is an aluminium smelter, where the penalties for loss of input power are massive, and can result in the plant needing to demolish large chunks of the equipment and rebuild them. Electrolysing water also needs additives, and filtering out the most common byproduct, chlorine, from the system as well, plus it is also incredibly energy intensive. Your cost to make from electricity would be more than double than reforming methane or natural gas, or by using syngas from coal in the Fischer–Tropsch plant process. If you have enough biomass on a reliable scale syngas direct would work better to run engines, plus give a food crop as well, though it would probably be best used on the farm itself to run the equipment for modern agriculture over diesel.
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@zapityzapzap Provided you have enough forced air cooling for that motor. Otherwise you have a very hot, then very burnt, motor and controller. Full power dissipation without the cooling fan on most motors is going to result in a very rapid rise in internal temperature.
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How do you make hydrogen commercially, but by chemical decomposition of methane or other natural gas. What is overall efficiency of that process compared to taking same energy of fuel, and turning direct to electric power in a large efficient power plant.
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@gregkramer5588 Well, a lot of the EU petrol comes from refineries in Portugal, and also there are large sugar beet plantings used to make ethanol, plus sugar imports used to do the same. I doubt Ireland actually has a oil refinery of it's own, like many smaller countries also lack, so would import a lot of fuel from the closest one, which is Portugal. Incidentally that refinery also ships a lot to the world, as VLCC tankers are very cheap to rent when travelling down Africa back to the oil supply countries, so you get low price shipping if you are bringing in, what to them, is just ballast in a tank.
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ss Mine go 5 years or 30 000 km, about half the recommended change interval of 7 years or 60 000km, so I do not have to worry too much. However as it is VW, and the second most common vehicle here, spares are both plentiful and quite cheap, and thus you have no real benefit of running till it is near failure. The tensioner actually costs more than the belt, and is also a change part. I am so thankful I do not drive GM, where they use the water pump as tensioner, and they are invariably rusted solid, or the bolts snap off in the block. With Ford and the CVH engine I had belt and water pump replacement down to a hour extra during service, mostly from making sure those bolts were nice and clean, and well lubricated. We did do a half hour change one afternoon, in a garage, after the pump had a bearing fail. 10 minutes to cool, 10 minutes till out, which was coincidentally the time it took the new pump to arrive from the other spares branch. They asked where the car was, and were surprised that the car, that pulled in 20 minutes ago, was the one needing the pump. Gasket compound on that new one was well cured, we still had 400km left to do that evening, and left with it still wet.
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ss It does both, acting as the idler, and also being able to swivel during installation to set the belt tension, then tightened down to hold it. That means large sections of the pump are exposed to the coolant, and there is a crevice that creates a nice corrosion cell in there as well, with 2 dissimilar metals to enhance it galvanically.
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As well you got an audience across the planet who watch you as well.
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Had a similar thing happen, hit unmarked roadworks in the rain, and totalled the tyre. Got the claim form, and submitted with location of the roadworks, and the bill for new tyre and alignment. 3 months later got 80% back in settlement. Those rims are not totalled, there are plenty of places that will take them, straighten them and reweld them up, and then X-ray them for any damage. Probably worth doing as a set of spare rims, though would not do track racing on them afterwards, just use as general driving rims. But yes, painted tyres and massive rims are expensive to maintain, both from the cost of the rubber and from the damage they can have happen to them with potholes.
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@brianhiggins2399 They import it, along with the fuel base as well, generally from one of the massive refineries in Portugal.
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I use ethanol based fuel, but this comes from Fischer Troph process, converting pretty much any carbon feedstock to syngas, which is then turned into various liquid fuels and chemical feedstocks, all of which are in general better that using oil to make them. Yes a lot of ethanol is produced, more as a intermediate and as part of the process. Another source is the old spent wort from beer making, which has a plant by me making all sorts of chemical feedstocks off of this fermentation as well, and one of the byproducts is actually used to make a popular spread.
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Big thing to influence reliability is frequent oil changes. Those tiny channels and tight tolerance fits will be rapidly destroyed by leaving the oil in too long, and it turns from a lubricating and cooling medium into a corrosive grinding paste.
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Orange peel is kind of common with low VOC paint finishes, seems to be a big thing with it, probably due to the longer drying times on the line, and the need to bake it as well. I see it on pretty much every new vehicle to a varying degree irrespective of manufacturer. As to the scratches, that is very likely a delivery issue, with it being driven without a full wrap of plastic from the production line, and then car carrier trucks and things like dust, road stones and srap marks from transport and moving it around.
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