Comments by "David Elliott" (@davidelliott5843) on "Engineering Explained" channel.

  1. An that's because its gutless ;)
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  2. The Tesla is 0.07 seconds slower to 60 mpb but 1/2 the cost. Oh hang on the Plaid is on the way. Sorry Porsche.
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  3. But you can't fit them over the brakes on this car. Best option is buy some aftermarket wheels and put the OEM in the shed.
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  4. The power control system is basically an ABS that controls power input rather than brake friction. This anti wheel slip should be just as quick operating as any ABS
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  5. Learn to ride a motorcycle. They don’t have a synchro gearbox so revs have to be matched with throttle blips going down the box and fast shifts going up. Do that downshift blip in a slow electronic throttle and it will grumble on you.
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  6. The diesel fuel standard for UK is EN590 which has a cetane value of 49. Shell Optimax diesel is 51 to 53. I assume Exxon has their equivalent. Higher cetane numbers means smoother combustion less knock, less smoke and less NOx. The USA allows a minimum cetane of 40 so they have a lot of room for improvement.
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  7. How about the Fiat MultiAir which uses engine oil pressure to control the valves by hydraulic action.
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  8. Shifting too slowly especially going down the box makes for a jerky ride as the revs never match. It’s also much tougher on the transmission.
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  9. The imperial systems keep going because they work on human scale and for normal tasks they make the arithmetic very easy. Of course for engineering tasks they make the maths really hard and error-prone hence the switch to SI units.
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  10. F1 became irrelevant when the V10s were banned. That noise was a huge part of the spectacle.
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  11. I'm sure you are right. Car and bike manufacturers are well known for not thinking out of the box on basic engine technologies. But to be fair Ford had a fleet of 2 strokes running in the Ka during the 1990s. It was held back by EU regulations so the Ka was marketed with the old tech crossflow 4 stroke. Konisegg(sp?) has a 4 cylinder 4 stroke turbo that has no cam shaft or cam drive. Its all electronically controlled and proven to work extremely well. Do we have them on the road? Do we heck!
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  12. Christian von Koenigsegg
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  13.  @sogerc1  Carboniferous is coal. It came from rotting plant matter.
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  14. Check out the Napier Deltic invented for high speed torpedo boats. Two stroke opposed pistons with three crankshafts and typically three rows of six cylinders and 36 pistons. They were timed so that one piston lead the other to open the exhausts before the inlets were opened. The third crank ran backwards to allow every row of cylinders to operate correctly.
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  15. The franchise dealers often don’t have a clue how to repair their cars. They simply plug in the computer and swap out an (allegedly) faulty part. The costs are charged back to the manufacturer. Present them with an out-of-warranty car and they cant get beyond the diagnostic computer screen
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  16. Two cylinders at each end of a sliding shaft with a generator coil between. Pistons fire alternately to move the coil back & forth. Control provided by electronics so no crank and no cams.
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  17. “Lift & coast” in an EV means regen braking. So, how much kinetic energy does the Plaid put back into its battery? Tyres are the same so it should be able to do this at the same rate as power gets applied under acceleration. Tesla could fit smaller friction brakes and not compromise stopping ability at all. Less unsprung weight = better road handling.
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  18. Dont forget 13 million tonnes of methane leaked away by the USA every year. At 85 times the warming effect of CO2 it's equivalent to 1.1 Billion tones of CO2. They dont tell us about that one and you wont smell it because the "odorant" is only added to domestic gas at the local distribution centre.
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  19. There’s another video where the ZF eight speed with lock up torque converter is shown to be more efficient than a manual. Personally I would accept a few compromises to not have the hassle of manual shifting. Epicyclic gears used in autos will take huge torque very smoothly and efficiently. The torque converter is usually locked up. It only really works for traffic crawling or moving away from standstill. The tiny loss of efficiency’s balanced by never needing to replace the clutch.
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  20. But fairly normal for OEM service agents.
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  21.  @SgtKanyo  When I want A to B travel I really don't want soul. I just want minimal hassle and the travel job done with. I dont need the clunky gear shifts, reluctant engines and wobbly handling of most commodity cars on the market. When I want soul, I'll get a Lancia Stratos replica with it's mid mounted 3.0 V6. Or maybe a Shelby Cobra. A Fiat Panda 100HP with turbo would be a great toy at a more reasonable cost but it's not a daily driver.
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  22.  @Opa_der_Kranke  It is a boxer but pistons oppose rather than push apart. Another interesting design is a four cylinder radial 2-stroke. It has all four con rods running on one (wide) crank pin. There is no master rod as seen on 4-stroke radials so the engine is as simple at the crank end as it is at the cylinder head. They give four power pulse per rev so torque vibration is very low. The top end and crank are in perfect balance so the engine is almost as smooth running as a rotary. The bottom end is dry sumped so oil consumption is not an issue.
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  23.  @LucioFercho  They were given the design as part of WW2 war reparations.
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  24. They all used Bosch engine management so no surprise they were all up to the same fakery.
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  25. Use an octane booster
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  26. If a fuel source cannot undercut coal on costs per Kwh then all it will do is displace the coal burn to people who can't afford the expensive "green" energy. No net change. Molten salt nuclear reactors especially the Moltex remove all of the hazards associated with pressurised water reactors and because they are so safe can be built and operated at lower costs than coal. With something that simple why go to all the trouble of digging up and burning coal. The Moltex actually burns waste fuel taken from existing reactors. It's cleaning up AND making money all at zero CO2.
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  27. I wonder if this could be added to the Ilmor 5 stroke adding even better efficiency. It uses two cylinders exhausting into a larger third cylinder. The 5th stroke is a secondary expansion. Thermal efficiency went up 15% over a normal engine.
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  28. Switch to steels and put your a Tesla alloys in storage. They are stronger and easily straightened if they do get dinged. The full set will be cheaper than one alloy. Fit Tesla aero covers and nobody will know.
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  29. A recent report shows the USA natural gas industry is leaking 13 million metric tons of methane each year, giving a leak rate of 2.3 percent. Methane has a global warming effect 85 times that of CO2 and when it's degraded over time its become CO2. in CO2 terms that 13 million tonnes wasted is really 1.1 Billion tonnes of CO2 equivalent. Coal has a horrendous CO2 emissions because most of it is carbon AND the thermal efficiency is never better than 30%. I cant find the figures but it's BAAD. Nukes and renewables are of course zero CO2. So its reasonable to use gas as the mean though that leakage effect is pretty nasty. The big question is why are we not using molten salt nuclear reactors like the new Moltex going up at New Bruswick in Canada. It will burn waste fuel from the old light water reactor next door and building it costs no more than a Combined Cycle Gas Turbine plant. Fuel costs are negative because they are being paid to take away the irradiated waste fuel. Coal is the cheapest fuel but overall the Moltex will be cheaper per KWH than a coal fired plant. When can we have more of these things? Cheap. Zero CO2. Uber safe it cannot explode or melt down. You could rip the top off and there would be no toxic clouds. The fuel is fully burnt so no long life waste.
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  30. Electric gets awful range when it’s not able to recover energy from deceleration. One pedal driving needs to evolve but it is the future. Porsche have made the error of making an electric car that apes a petrol car. So the driving range is terrible and the new Tesla Plaid has already blown it into the weeds.
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  31. The 10% transmission loss suggests the torque converter (locked up) and axle are generating 112.5 Kw of heat. That’s a heck of a lot for one bevel box and it’s unlikely there is a an oil cooler the size of a normal car radiator I suggest the axle is 95% or mabe 97% efficient making top speed even faster.
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  32.  @ambitiosus1079  Just what I was going to say, though I'm paying 13p per KWh and less on the night rate. I would like to know how the Tesla compares on CO2 emissions. Electricity is mostly made by burning fossil fuels and its already been shown the renewables have not reduced the overall fuel burn. The intermittent and unreliable power output has to be topped up by running fossil plants inefficiently. Nett saving on CO2 - none.
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  33. Locking differentials send power to ALL WHEELS ALL OF THE TIME. If any wheels lift, they still turn but won’t spin.
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  34. The Wankel is fundamentally flawed. Why are Mazda still flogging this dead horse? Why are they not using the triangle stator with oval rotor design used by “Liquid Piston”?
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  35. Back in the 1980s I worked with Terex TS40 (40 cubic yard) earth scrapers used to move coal at a power station. Some had Cummins turbo diesels (sorry cant remember the model) and some had Detroit 2 Strokes in The Cummins were regularly blowing turbos sometimes taking cylinders with it. The Detroits just ran and ran. Never any trouble and always very powerful. They blew black smoke when driver floored the accelerator pedal, but at constant load were very clean. Cummins would smoke when worked hard. Interestingly, the Cummins powered machines had an eccentric balance weight on the rear engine crank that generated considerable vibration. If that was not fitted the rear engine would quickly break it's crankshaft. The cause was harmonic vibration from the front engine. The Detroits never had that problem.
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  36. There was a British engine in the 1980s that never went beyond prototype. It had a small primary air cylinder where rich mixture was mixed and ignited. The part-burnt gas exhausted into the main cylinder containing hot compressed air where the burn completed. It was clean and efficient.
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  37. The aftermarket rotors seem to heat faster suggesting they extract more energy = better braking. As said needs a track test.
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  38. In U.K. the tow weigh is 85% of the vehicle weight. For large 4x4 that doubles. Max speed normal roads is 50. Motorways - you are allowed 60. I used to tow a big caravan (trailer) with a large diesel car. No matter how you cut it the miles per gallon was cut by 50%. At speed or ordinary roads with accelerating and slowing I could never beat 20mpg. Solo it would do 40mpg. Electric cars will be just the same. If your range is normally 200 miles that will drop to 100 miles. The only solution I can see is for trailers to have a car traction battery to support the car battery. Unfortunately that means less payload. But it does give both an easier time so efficiency might improve. Another option would be a generator in the trailer. OMG it’s not green. Well tough but it would get the job done. Also we could make generators a lot more efficient if we really wanted to.
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  39. Serial hybrid is an electric transmission. It’s far more sophisticated than the usual parallel hybrid where a motor is bolted alongside the engine. The industry screwed itself by ignoring serial hybrids and they now have to start at scratch with generators motors and inverters.
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  40. You never see any double declutch or rev blips on downshifts on the films - because the actors cant do them properly.
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  41. What about the voice coil direct injection 2 stroke? The coil injects a premixed rich air fuel load after the ports have closed. Tumbling air in the cylinder filters the rich primary fuel load. Variable valve controls the exhaust port timing and Reed valves control inlet air flow. Basically uses the primary air secondary air arrangements found in continuously fired biller burners.
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  42. Motorcycles use stainless discs with sintered metal pads. They don’t have servos but give excellent stopping power and long service life. Why is that combination not used on cars? Saying that my Fiat Panda discs and pads cost £20 per wheel.
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  43. Combine this with a rich premixed air fuel mixture injected by voice coil pistons. That gives an easily ignited mass of air and fuel surrounded by pure air for clean combustion. The ultimate opposed piston engine was the Deltic with three banks and three cranks 9 cylinders 18 pistons.
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  44.  @davidbesant  If you use compressed natural gas in UK (which very few do due to installation costs), you will be required to have a separate gas meter for the car filler and you will pay excise duty on that tax. Sooner or later, the same will happen with electric cars. We are already being prepared for this with NOx emissions and tyre dust emissions.
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  45. Four years since Qoros showed their concept yet Big Auto has ignored Freevalve. They just roll along doing more of the same. Right there we have the reason why Tesla is hoovering up their profits.
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  46. I have a Fiat Panda 100HP (yes I know opposite end of the scale) but it's 15 inch wheels with 195 R 50 tyres are very easy to buckle. I have two that are usable but need to be replaced. It's a special model so wheels are silly money and even more frustrating when it's an old car like mine. My point? Don't expect 17" wheels to cope much better on the heavy Tesla that's if they will fit over the brakes. But (assuming they will fit), I would get a set anyway and hope that next time only one gets wrecked so I can use the spare wheel.
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  47. Heavy plant and commercial truck engines use ultra fine bypass oil filters which take a small percentage of the full flow. Over time they clean out the really fine particulates which deplete the oil's ability to keep dirt in suspension. Due to these filters, they hardly ever change the oil it's just topped up as needed.
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  48. The low compression of the early V8s was probably due to the very low octane gasoline. Not to mention the side valves - Lawnmower style.
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  49. Hydrogen does not exist on Earth as a raw element. It has to be reacted from a hydrogen compound which defeats the point. But nuclear power can be used to crack water directly. All light water reactors use reformers to keep the plant safe from hydrogen/oxygen created by the neutron flux in the cooling water. If the gases were simply removed and separated we would have hydrogen as a free byproduct.
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  50. A British startup (Naro) designed a two seat tandem car that little wider than a motorcycle. It also leaned into corners like a motorcycle. It gave the safety of a car with the road lane usage of a bike so twice as many cars could use the same road space. It was a technical marvel but failed of course. The motor industry and buyers are just not interested in such innovations.
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