Comments by "John Burns" (@johnburns4017) on "Engineering Explained" channel.

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  59. It is best you pour in the viscosity the makers state and make sure it is "fully" synthetic and conforms to the latest API which is now SN I believe. Thinner oils have to be "fully synthetic", as they are the only oils that can handle it. Thinner oils are meant for less resistance and better fuel consumption. Thinner oils also get to the bearings quicker on start up, when the oil has drained down after the car is standing for a while. Thick oils are a big problem on starting especially in winter. The problem is getting oil to the bearings fast enough as the oil is very thick at low temperatures. That is where fully synthetics shine. They do not become too thick in very cold temperatures starving the bearing of oil on start up. In place like northern Canada using a 0W oil is near essential as the oil can get so thick when the engine is cold. Fully synthetics also have far greater "shear", that is the resistance to be compressed, keeping metal surfaces apart. Fully synthetics last longer as they break down far slower. A mineral oil can be broken down substantially after 1,000 miles. Fully synthetics resist and are stable at great heat. They were developed for jet aircraft. Mobil 1 had an advert in the 1990s of two frying pans on a stove, one with fully synthetic in the pan and one mineral oil. They left the burners on. The mineral oil ended up black, burned, dry, hard and caked up. The fully synthetic was still as it was after igniting the burner. This is relevant as all engines have hot spots which will burn mineral oil, hence caked oil forms in parts of the engine. When engines idle and oil and coolant are not being pumped around fast enough it can cause engine hot spots and burning of mineral oil. Avoid semi-synthetics as many are con. The synthetic part may only be 5-10% of the oil. Only drop from a fully synthetic to a semi when the engine is using oil. So in short, Get the viscosity your engine needs and pour in a high quality "fully synthetic" and have the latest API number. The highest API numbers are always "fully synthetic" oils. Do not go on old wives tales and the comments here is full of them.
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  185. Mazda have done very promising research on HCCI ignition for its SkyActiv-R rotary engine project using research from its SkyActive 2 program. They have removed the need to locate the spark plug outside the combustion chamber to allow the rotor to sweep past. Mazda solved this in the SkyActiv-R rotary project. Rotaries generally have high compression ratios giving the design easy adoption of homogeneous charge compression ignition (HCCI). It looks like the next Mazda rotary will not have a spark plug and be HCCI ignition. Fuel consumption will match piston engines and when used at a constant speed range-extender gennny as in a hybrid, outperform piston engines with all the advantages of low weight, small size, super-smooth, simplicity, etc. The efficiency and longevity of rotaries is excellent when at constant speeds and low revs. The expectation will be that the engine will be introduced in 2020, the 100th anniversary of Mazda. Looking good. Explanation of HCCI from wiki: "Homogeneous charge compression ignition (HCCI) is where the fuel/air intake is a pre-mixed lean air-fuel mixture then compressed to the point of auto-ignition. Electronic spark ignition is eliminated. Gasoline engines combine homogeneous charge (HC) with spark ignition (SI), abbreviated as HCSI. Diesel engines combine stratified charge (SC) with compression ignition (CI), abbreviated as SCCI. HCCI engines achieve gasoline engine-like emissions with compression ignition engine-like efficiency. HCCI engines achieve low levels of nitrogen oxide emissions (NO x) without a catalytic converter. However, unburned hydrocarbon and carbon monoxide emissions still require treatment to reach automotive emission regulations."
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  210. http://www.roadandtrack.com/new-cars/future-cars/news/a31802/mazda-ceo-kills-hope-new-rx-9/? The rotary is NOT dead. The rotary is made by 5 companies around the world right now. That Road & Track article all makes sense. The rotary as a range-extender is by far the best application for this engine. "Mazda–like the rest of the automotive industry–has put priority on introducing hybrid and electric cars in the face of tightening emissions regulations. The company has entered a partnership with Toyota to develop electrified vehicles. Toyota is doing research on a free piston linear generator for hybrids. About 16 organisation around the world are doing so, and have been for over 20 years, and no one has perfected it yet. https://en.wikipedia.org/wiki/Free-piston_linear_generator The rotary looks the best bet for a small range extender engine. When on a constant speed & load the efficiency is better than piston engines. "If we were to restart production of the rotary engine again, we need to make sure it wouldn't be just short-lived," said Kogai. "We need it to meet future emissions regulations. We are still conducting our R&D activity to overcome any issues we have with emissions and fuel efficiency." Kogai says that the most likely application for the rotary would be as a range extender in an electric car. Mazda made a rotary range-extender for a Mazda 2 three years ago. Google it, journos drove it. They said they would like to also make a portable generator using a rotary to keep production figures up. Mazda stated that any new rotary would most probably have HCCI ignition. Also look at recent SPARCS and CREEV advancements from the UK. The rotary using SPARCS, CREEV and HCCI ignition is the perfect engine for a range-extender being a third of the size and weight of piston engine. A range-extender engine is only a part time engine, so longevity is guaranteed. https://en.wikipedia.org/wiki/Wankel_engine
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  217. I was talking to a ship designer and they are always looking at ways of cutting running costs. Some were looking ahead and favoured rotary engines in banks in cruise ships if they were made large enough. The 4 deck high Wartsila and Suzler engines when needing overhauling means the ship is dock, which means down time which costs. Ships and moreso cruise ship operators do as much maintenance as possible under way. They even paint the sides of the ship when in a calling port. They want the ship in dock only for essential dry dock maintenance like azipods, props or the keel. They want maintenance to be ongoing as the ship is moving and earning money. Some ship's designers are looking ahead and favouring larger rotary engines in banks (slide out modules say 1.5 metre by 1.5 metre complete with generator) in cruise ships. Rotaries are one third of the size and weight for the same power output. The smoothness is a great asset in passenger accommodation. Rotaries scale up seamlessly. The rotary genset modules can be phased in, in stages to what the ship's power demand is, rather than running these massive Sultzer engines when there is low demand. Then they can slide out a genset module in port and slide one in, which will take a few hours. The genset module in port can be overhauled onshore and the ship continues with no downtime maximising efficiencies and revenues. The rotaries niche is where a constant speed is appropriate as in genset applications. Then the rotary overtakes the piston/crank engines in economy. Other niches are aircraft because of the superb power to weight ratio over piston/crank engines and UAVs currently exploit this well. Applications for ship gensets are way down the line and probably will only come about when there is a wider acceptance in vehicles, although large rotaries were commercially operational in the 1970s, Ingersoll Rand making the largest which reliably ran for many years. As to ships, keeping the hull small enough to negotiate the Panama locks and packing as much cargo or passengers inside as possible increases the profitability. Replacing large engines with smaller lighter units which are flexible to the location inside the hull gives a ship designer great scope. More economical engines means smaller fuel tanks which again gives over more space for revenue earning cargo or passengers. Being secured in a strong niche market may elevate the rotary as the first choice of engine in time, as direct drive applications become rare. Light weight rotary engines can be located out of the depths of the hull, instead of all laying on the keel. The flexibility of design is there. Many ships have Azipods for the the obvious manoeuvrability and also that they liberate space in the hull. Cruise ships want as much space as possible for revenue gaining. They cost a lot to run in crew and fuel costs. On the lower decks the crew are housed. Liberated engine space can accommodate more crew and lower the crew down maybe a deck or half a deck and utilise the liberated space for passenger functions, while moving these functions down decks will again liberate space on upper decks for more revenue earning passenger cabins. The industry will move to smaller lighter engines if they are available for sure. They moved from steam to turbines and diesel piston engines. They move with the economic flow. Cruise ships use an amazing level of fuel, especially in hot climates when the a/c's are running. Size of propulsion and ancillary equipment in ships now matters. There have been large rotaries and they scale up seamlessly. A new large rotary in a genset would have the new innovations and improvement of over the past 40 years. Some newer rotaries are cooled through the driveshaft for instance giving engine longevity as hot spots are eliminated. There is concern that vibration of ship's diesel engines could damage ancient historical buildings in places like Venice. Venetians constantly complain of this. Vibration is greatly eliminated using smooth rotaries. Having been on a number of cruise ships I can attest that vibration is a problem and I am always on around the 12th deck where it is minimal. What it is like further down I dread to know. I pity some of the crew near the engine room. Cabins on lower decks tend to be cheaper because of engine noise and vibrations; less revenue. Look at the size, and weight, of a ship's diesel engine. It is massive taking up to 4 decks in height and cruisers have banks of these. The advantages of rotaries are easy to see.
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  384. Direct fuel injection and laser ignition will improve the Wankel considerably when introduced. The problem of unburnt fuel in the exhaust will be eliminated improving emissions and fuel consumption. The engine performs very, very well in fuel consumption and emissions running at a 'constant speed' turning a generator - its most efficient "sweet spot". Wankels lose efficiency dramatically when they are revved up and down as when directly driving a car. The engine has a vastly superior power-weight ratio than piston/crank engines and is about one third of the size and weight of a piston engine for a similar power output. All these positive attributes combine to make a superb range extender, when the wheels are turned by electric motors. If a car is plugged in each night and uses grid power to run most of the time, then wear on these units will be negligible. As the engine is only periodically used, the life of the engine is greatly extended. Also newer metallurgic techniques are being used to make the engines. Even when batteries are depleted, the Wankel can provide enough electricity to power the car and still be economical. The first ever series-hybrid plane flew in June 2013 - using a Wankel engine because of its small size and light weight, and an electric prop. The makers say it can be scaled up to around a 100-150 seater plane. The Wankel engine(s) can be in the fuselage for better weight distribution with small electric motors on the wings giving lighter, and cheaper, wings. About 5 companies still make Wankel engines for special purposes such as drones. The sooner they are introduced in road vehicles in series-hybrid form the better. The Wankel has finally met its niche.
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  388. Rotaries are better suited to constant speed, high efficiency genset applications rather than direct drive via gearboxes. In that application piston engines cannot compete. Rotaries are better suited for series-hybrid cars being much superior than piston engines. Direct fuel injection and laser ignition will improve the Wankel considerably when introduced. The problem of unburnt fuel in the exhaust will be eliminated improving emissions and fuel consumption. The engine performs very, very well in fuel consumption and emissions running at a 'constant speed' turning a generator - its most efficient "sweet spot". Wankels lose efficiency dramatically when they are revved up and down as when directly driving a car. The engine has a vastly superior power-weight ratio than piston/crank engines and is about one third of the size and weight of a piston engine for a similar power output. All these positive attributes combine to make a superb range extender, when the wheels are turned by electric motors. If a car is plugged in each night and uses grid power to run most of the time, then wear on these units will be negligible. As the engine is only periodically used, the life of the engine is greatly extended. Also newer metallurgic techniques are being used to make the engines. Even when batteries are depleted, the Wankel can provide enough electricity to power the car and still be economical. The first ever series-hybrid plane flew in June 2013 - using a Wankel engine because of its small size and light weight, and an electric prop. The makers say it can be scaled up to around a 100-150 seater plane. The Wankel engine(s) can be in the fuselage for better weight distribution with small electric motors on the wings giving lighter, and cheaper, wings. About 5 companies still make Wankel engines for special purposes such as drones. The sooner they are introduced in road vehicles in series-hybrid form the better. The Wankel has finally met its niche. It takes only 25 to 30hp to propel a large American car down the highway at 70mph. Yet they put engines in them that can output 150 to 200hp. Most of that output is for acceleration and heavy loads. Highly inefficient. The great thing about a series-hybrid is that the generating engine works totally independent of the demands of the electric driving motor, enabling maximum efficiency when running. This means the generating engines can be greatly downsized. The battery acts as an energy buffer to give acceleration boosts.
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  398. The Final Eclipse It takes only 25 to 30hp to propel a large American car down the highway at 70mph. Yet they put piston engines in them that can output 150 to 200 HP, a Rolls Royce's engine outputs 450 HP. Most of that output is for acceleration and heavy loads. It is highly inefficient because there is no supplemental power (with an energy buffer) to use when extra power is needed. Efficiencies rise when power is modularised into power units and modules brought in when needed - sequenced. The great thing about a series-hybrid is that the generating engine in the genset works totally independent of the demands of the electric driving motor, enabling maximum efficiency of both when running. This means the generating engines can be greatly downsized as the genset engine is sized for average use, not peak use. The genset can be charging the battery energy buffer when the vehicle has low demand. The battery acts as an energy buffer to give acceleration boosts and assist in heavy loads. The positive attributes of a Wankel engine, one third of the size and weight and very smooth, combine to make a superb range extender easily hidden in a vehicle. If a car is plugged in each night and uses grid power using the batteries to propel the vehicle most of the time, then wear on these Wankel genset units will be negligible as it will be a part time engine (genset). Even when batteries are depleted, the Wankel can provide enough electricity to power the car and still be highly economical. The sooner Wankels are introduced in road vehicles in series-hybrid form the better. The technology is all here. Once successful and the public accept a Wankel, as decades of negative propaganda have poisoned their minds, this should pave the way for larger implementations in Wankel series-hybrids. There have been some advances in Wankel engines negating many of the disadvantages. HCCI ignition by Mazda and SPARCS and CREEV in the UK. CREEV is an ‘exhaust reactor’ that consumes unburnt exhaust products (was a big problem with Wankels) delivering lower emissions and improved fuel efficiency. A sort of turbo. Wankels are very efficient when run at a constant speed as in genset applications (range-extenders). The Wankel has finally met its niche. Makers are too slow in implementing. Once we see one successful implementation we may see a flood. Mazda and Toyota have pooled resources to produce a viable range-extender.
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  412. Pablo Ricardo de Tarragon Laser ign can project FOUR sparks deeps inside a combustion chamber, which is ideal for a rotary with its moving combustion chamber. NATO want to standardise on fuel HFO. It can be spark ignited by preheating it. Rotaries in R&D have excellent thermal efficiencies when run at constant speeds. Those 4 deck high Wartsila Suzler engines when needing overhauling means the ship is dock, which means down time which costs. Ship and moreso cruise ship operators do as much maintenance as possible under way. They even paint the sides of the ship when in a calling port. They want the ship in dock only for essential dry dock maintenance like azipods, props or the keel. Some ship's designers are looking ahead and favouring larger rotary engines in banks (slide out modules say 1.5 metre by 1.5 metre complete with generator) in cruise ships. Rotaries are one third of the size and weight for the same power output. The smoothness is a great asset in passenger accommodation. Rotaries scale up seamlessly. The rotary genset modules can be phased in, in stages to what the ship's demand is, rather than running these massive Sultzer engines when there is low demand. Then they can slide out a genset module in port and slide one in, which will take a few hours. The genset module in port can be overhauled onshore and the ship continues with no down time maximising efficiencies. These big diesel engines are also filthy. Such huge ships emit as many air pollutants as five million cars going the same distance. "Southampton, which has Britain’s second largest container port and is Europe’s busiest cruise terminal, is one of nine UK cities cited by the World Health Organisation as breaching air quality guidelines even though it has little manufacturing." http://www.theguardian.com/environment/2016/may/21/the-worlds-largest-cruise-ship-and-its-supersized-pollution-problem Some companies are running the cruise ships on LPG to reduce pollution. Rotaries as constant speed gensets are also very good at burning hydrogen. The thermal efficiency of these diesels is because they run at constant speeds. Car engines do not, so efficiency is very low with cars. You are right, in a rational world petrol engines are obsolete and electric is the way. The best range extenders for cars are rotaries with the new R&D very promising superior performance over piston/crank engines. They can be easily hidden in cars being one third of the size and weight, which is a fantastic attribute. Also, as range-extenders are part time engines the efficiency is not a great point - as they will be rarely used. Size weight and smoothness matters. But at a constant speed a rotary with the new advances running as its 'sweet spot' exceeds piston/crank engines. The rotary does not like being revved up and down. Rotaries do not have sealing problems that is myth from 50 years ago.
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  414. Pablo Ricardo de Tarragon LPG is not unsafe. It may be problematic in certain failure conditions. But the failure conditions can be accounted for with safety mechanism put in place. In the early days of petrol there was explosions and fires all over. Heavy fuel oil only caught on because of reduced insurance costs. Now we know how to store, transport and use petrol. Cruise ships, and other ships, ARE using LPG right now. It is a hell of a lot cleaner and stops people preventing them entering places like Venice on pollution grounds. Look at this article about the burning of heavy oil by large cruise ships. It is a big problem. http://www.theguardian.com/environment/2016/may/21/the-worlds-largest-cruise-ship-and-its-supersized-pollution-problem Ships designers are looking at dispensing with those old huge diesel engines and going over to phased in genset modules for reasons I have already outlined. Reducing downtime, and maintenance costs on a cruiser most than offsets higher fuel costs, if there is any. As to road vehicles, the market has to go over to series-hybrids driven by high efficiency electric motors. Small to average sized cars can have a Lith battery bank that will give 300 miles range. The part time range-extender has to be 'physically small' to fit in the car, and smooth. That is where the rotary comes in. Forget the tripe about seals lasting a few years. A modern rotary using the latest advances used as a constant speed genset will last and last. Many go way over 100,000 miles. As as range-extender it is only a part time engine it will last the life of the car. Rotaries do not like to be revved up and down. Fuel economy and emissions suffer. When they are they did have seal lift off as one chamber can have more pressure than the adjacent chamber (although this has been rectified by some makers). Running them at a constant speed just above the seal lift off speed solves a lot. Rotaries suffered though unburnt fuel in the exhaust. Multi-point lazer ign solves that. Designed to run a constant speed then the design is much easier to maximise fuel economy and give superior emissions as most is a constant. Mazda are R&Ding a rotary engine now. They say it will be out next year for the 50th year of the Cosmo, their first rotary car. UAVs use rotaries because of their small size and light weight which is a great advantage in a plane.
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  659.  @marshallmonroe884  There is a myth that the Germans were way ahead of the British in jet engines and planes in WW2, when the opposite is true. The WW2 German jet engines were extremely unreliable with low performances and very high fuel consumption. The German axial-flow turbojets never worked as they wanted being developed up to 1953 by the French to obtain a usable engine. The French lost a lot of time playing around with the German engines, instead of working with the British. The French and Soviets after WW2 tried to improve the German axial-flow engines and largely failed. The Germans did not invent the axial-flow turbojet, they based everything on Frank Whittle's patents. The British Metropolitan-Vickers F.1 axial-flow engine was running on a test bed in 1941. The F.2 was an axial-flow being an extremely advanced design using a nine-stage axial compressor, annular combustor, and a two-stage turbine. It powered a Meteor in November 1943. It was considered unreliable and never saw use during the war, hence why the British went for the reliability, controllability and quick development of the centrifugal turbojets. The Metro-Vick F.3 was the first ever turbofan in 1943. Metro-Vick developed the F.9 Sapphire, however left the jet business in 1947 giving all their designs to Armstrong Siddeley, who commercially produced the Armstrong Siddeley Sapphire engine, which was licence built in the US as the J-65. The British in order to get a usable and reliable jet engine, with the technology of the time, went for a centrifugal design rather than the troublesome axial-flow design. This design produced less thrust than an axial-flow but was quicker to develop and reliable outperforming the best piston engines planes at the time. It took 5 months to develop, while the first reliable axial-flow engine was the 1950 Rolls Royce Avon, which took 5 years to get right. The Avon is still in production as a ground based gas turbine, with the aero version in production for 30 years. In 1945 the French made and tested some German designed turbo jets made with quality steel unavailable to German industry in WW2. They ran for 25 hours instead of the 10 hours of the Germans engines that used poorer quality steel. Not much better. The German axial-flow engines failed because of heavy design flaws. The centrifugal compressor used by the first British Meteor plane was fine and much more reliable, but unable to reach high compression ratios. This limited performances. Centrifugal compressors were used up to the 1960s. In 1945 the team from the French ATAR laboratory plus some BMW and Junkers engineers, were engaged by the French SNECMA research bureau, with the objective to build a new reliable and performing axial-flow turbojet. The BMW 003/Jumo004 was considered unusable. It was tested on the first French jet aircraft, the 1946 So6000 Triton, overheating and exploding. The plane only flew with a Rolls Royce Nene centrifugal turbojet. The ATAR project took 6 years to produce the first acceptable axial-flow turbojet (ATAR 101 B1), produced in 1953. So 8 years research and developments by the French using the German jet engines as the base. It was installed on the first French jet fighter, the Dassault Ouragan. The French lost a lot of time because the German jets had poor efficiency and some concept fails. Essentially in the combustion chambers and fresh air circulation to reduce the external temperature of the engine. The BMW jet was known for overheat problems which precluded fuselage installation. The question at the end of WW2 was: what is the most efficient way to produce jet fighters? The answer was clearly not adopting the German design of engine and fuselage. The build costs for a jet engine were much higher than a piston engine, with the fuel consumption near 3x. The centrifugal compressor the British adopted in some planes was the best choice with 1944-45 technology, more compression pressure was not an advantage when the hot turbine was unable to resist higher temperatures. The German turbojets had big overheat problems as the engine would not work in an enclosed fuselage for single engined fighters. This defect was immediately noted by the French on the 1946 "SO 6000 Triton" prototype, and by the Soviets on the 1946 Mig 9. The Soviets quickly replaced the BMW 004B2 by the centrifugal Rolls Royce Nene which worked without problems, dismissing the BMW engine for fighter planes. The Rolls Royce Nene was copied to the last nut by the USSR being installed in the Mig 15 being used effectively in the Korean war. The Meteor was the first proper fully developed jet plane introduced operationally. The 262 was slightly faster than the Meteor F3, but extremely unreliable. The British would never put into the sky such an undeveloped plane as the me262. The British could have had a jet fighter operational in 1941, but it may have been as bad as the me262. The Germans advanced R&D on jets after they interrogated captured British RAF men. They learned the British were advanced in jet technology and flying prototype planes. Until then the Germans had no intention of mass producing jet planes. The rushed together Me262 started claiming kills on 26 July 1944, the Meteor claimed its first V1 kill a few days later on the 4 August 1944. But the Meteor was a proper fully developed jet plane, not a thrown together desperate effort as the me262 was. The me262 fuselage was similar to a piston plane with the pilot over the wings obscuring downward vision, while the Meteor was a proper new design fuselage specifically for jet fighters with a forward of the wings pilot position giving superior pilot vision, as we see in planes today. The cockpit was very quiet. The sweptback wings of the me262 were to move the engines further back for better weight distribution, not for aerodynamic reasons as is thought the case. The me262's airframe was based on piston engine planes, even with an initial rear tail wheel. The tricycle landing gear was only introduced when it was found the thrust of the jet engines would scorch the runway surface as the exhaust faced downwards. The Meteor's airframe was designed purely for jet propulsion even with a high tail to prevent thrust interfering with the tail which could affect control. Centrifugal compressors were not obsolete being used in turboprops. Between a turbo jet and a turboprop, the only difference is the turbine, not the compressor. The last centrifugal compressor jet engine still in service on a handful of commercial aircraft like the Fokker 27, is the Rolls Royce Dart turboprop. A very reliable engine made in 27 versions, but with high fuel consumption to modern engines. The Rolls Royce Dart Turboprop turbo jet engine was produced the longest, being a comparable design turbojet to the likes the Rolls Royce Nene. The rugged engine was produced from 1946 up to 1987.
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  665.  @marshallmonroe884  ♦ German engineer Ohain did not design a reverse flow engine. His engine had a centrifugal compressor and a radial inflow (centrifugal turbine - a design never used in any production engine - this was a patent filed by Whittle). Ohain even commented on its unusual design when he read Whittle's patent prior to filing his own: From Ohain's biography: "When I saw Whittle’s patent I was almost convinced that it had something to do with boundary layer suction combinations. It had a two-flow, dual entrance flow radial flow compressor that looked monstrous from an engine point of view. Its flow reversal looked to us to be an undesirable thing, but it turned out that it wasn't so bad after all though it gave some minor instability problems." ♦ Whittle's reverse flow design is the basis for almost all turboprop engines in production; ♦ Britain had axial-flow engines running in 1941 - the same time that Franz had his Jumo running. The Metrovick F.2 flew in a Meteor in 1943. The F.2 transpired into the Sapphire which the US built under licence as the J-65 and then modified it as the J-47; ♦ Westinghouse in the US was given a Whittle engine, and plans for improvements. They made such a hash of it that Whittle had to go to the US to assist. The US government gave the project to GE who made the I-16 which transpired into the first US built jet engine. The US licensed the Ghost for the P-80/T-33 and the RR Nene. The Nene was used by the Soviets in the MIG 15; ♦ Ohain's engine was not produced being shelved by 1943. No engine was built using his design; ♦ Whittle also R&D'd axial-flow engines. The metallurgy was not advanced enough at the time. Whittle's engines produced far more thrust than the German axial-flows and far more reliable; ♦ The PT-6, PWC 100/150 are derivatives of Whittle's designs being still produced; ♦ • Whittle's centrifugal-flow engines were built under licence in the US after WW2 - the J-33, J-42 and J-48; • The Olympus was the world's first 2 shaft turbojet and the first to exceed 10,000 pounds of thrust; • The 1950 Avon was the first reliable axial-flow engine. Also the longest produced gas turbine in history being still in production as a land based generator; • The RR Conway was the world's first turbofan; • The RB-211 was the world's first 3 shaft turbofan; • The Rolls Royce Trent was the world's first turboprop to fly; • British axial-flows led the post war world in technology and power; • The axial-flow Sapphire was built in the US as the J-65. The GE J-47 was based on the Sapphire. Frank Whittle invented the modern turbojet.
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  677. From Mazda.... The Mazda MX-30 e-Skyactiv R-EV is a series plug-in hybrid that offers the same customer values as the pure electric Mazda MX-30, while simultaneously offering new ways of using a car as a battery electric vehicle. With a 17.8KWh battery, the R-EV has a 53-mile pure electric range, and using Mazda’s unique rotary engine technology, the all-new 830cc single-rotor petrol engine acts as a generator to enable longer distance drives without range or charging anxiety. With no mechanical connection between the engine and the wheels, the rotary unit simply acts as a generator, ensuring the MX-30 R-EV always drives via the electric motor to deliver a seamless EV driving experience. With more than half a century of expertise in the development of rotary engines, Mazda selected the rotary powerplant for this application due to its unique ability to produce the required output from a small, light and easily packaged unit. The rotary engine is placed neatly alongside the generator and high-output motor in the engine bay. The combination of the 17.8kw battery and 50-litre fuel tank create a unique series plug-in hybrid with a flexible total range of over 400 miles, while a WLTP CO2 output of just 21g/km ensures class-leading environmental performance. Compatibility with both AC charging and rapid DC charging is another benefit, meaning 3-phase AC charging takes around 50mins, while for maximum customer flexibility, DC rapid charging can be completed in around 25 minutes. The Mazda MX-30 R-EV has three drive-modes to suit different driving situations: Normal, EV and Charge, and thanks to a 125kw/170ps output, it delivers slightly better acceleration performance than the 145ps fully electric MX-30 . Available to order now, for UK arrival in the summer, the Mazda e-Skyactiv R-EV is offered in the same highly specified grades as the all-electric e-Skyactiv MX-30: Prime-Lime, Exclusive-Line and Makoto – while bespoke to the R-EV, the range is topped by the Edition R. Revealed on the Brussels Motor Show stand, this limited edition launch model has stand out features inside and out, and is offered exclusively in the unique colour combination of Jet Black with Maroon Rouge side pillars and a black roof. Mazda MX-30 e-Skyactiv R-EV Edition R With the R moniker standing for return, just 400 Edition R models will come to the UK to celebrate the return of the rotary engine. The Maroon Rouge colour accent pays homage to the roof colour of the Mazda R360 – Mazda’s first passenger car. Inside, the front seat headrests are embossed with the rotary symbol and Edition R name, while the mats feature the rotary badge and a single white line of 2.6mm stitching matching the width of the rotor apex seal grooves. The same nod to the rotor apex seals can be found on the sculpted sides of the key, which also features horizontal sides that curve at the same angle as the sides of the rotor. All versions of the Mazda MX-30 e-Skyactiv R-EV feature a rotor badge on the front wings and an e-Skyactiv R-EV badge on the tailgate. Unique wheels differentiate the R-EV: Prime-Line with a dark grey finish and Exclusive-Line, Makoto and Edition R a black diamond cut finish. With the MX-30 range starting at £31,250 – Prime-Line and Exclusive-Line R-EV models are priced identically to the BEV version, giving customers ease of choice with price parity. Makoto R-EV models demand a small £450 price premium over the pure electric version and at the top of the MX-30 range is the R-EV only Edition R – priced at £37,950 it is limited to just 400 examples in the UK. Between the launch of the Mazda Cosmo in 1967 and production of the RX-8 ending in 2012, Mazda mass-produced more than 2 million rotary engines. Adapted to meet the needs of our times the rotary engine is now back being used as a power generator rather than a drive unit. The new 8C rotary engine is a 830cc single rotor with a 120mm rotor radius and 76mm rotor width, its compact size enables coaxial placement and integration with the electric motor, decelerator and generator to achieve a unit with an overall width of less than 840mm, allowing it to fit under the bonnet without changes to the MX-30 body frame. Thanks to the use of aluminum the engine is over 15kg lighter than the twin-rotor Renesis engine used in the RX-8. The use of direct fuel injection reduces emissions and increases fuel economy, while the engine also features an Exhaust Gas Recirculation (EGR) system to improve efficiency at low rpm and low load running. With a 50-litre fuel tank the rotary generator allows for long-distance travel without the need for regular fuel station stops. A 17.8kwh battery was chosen to ensure a enough capacity for a 53-mile electric-only driving range while at the same time considering the environmental impact of the battery over the entire vehicle life cycle. The MX-30 R-EV’s high output 125kw/170ps electric motor can produce up to 260Nm of torque, while the new R-EV retains the same relaxed, accurate and engaging driving experience as the pure-electric MX-30. The MX-30 e-Skyactiv R-EV features three driving modes: Normal, EV and Charge, however the choice of mode does not affect maximum vehicle speed. Normal mode delivers electric drive as long as there’s enough battery charge. If more power is required than the battery level can deliver – for example, when accelerating – the rotary engine generator will activate based on the degree of accelerator opening and supply the battery with more power. Thus the MX-30 e-Skyactiv R-EV delivers outstanding acceleration performance and ensures drivers can always enjoy the car. Drivers can turn EV mode on when they want to stay in electric drive for as long as possible. This mode will ensure the vehicle uses electric drive exclusively until the battery is completely drained. It should, however, be noted that if the driver needs to accelerate suddenly and purposefully depresses the accelerator pedal significantly beyond a certain point (equivalent to the kickdown switch function on a standard automatic transmission vehicle), the rotary engine will activate and generate the power needed for the car to accelerate as powerfully as possible. Charge mode can be used to safeguard the necessary amount of battery for situations such as the need to save zero emissions running for particular urban environments, additionally drivers have the option of setting the amount of battery charge they want to reserve in increments of 10%. The generator will activate when battery charge drops below the specified reserve level, charge the battery to the set level, and maintain that level of charge. Once battery charge is above the set level, the car will operate in the equivalent to Normal mode until the battery depletes to the specified level. It will then use the rotary engine generator to keep the battery at that level. Commenting on the reveal of the Mazda MX-30 e-Skyactiv R-EV, Jeremy Thomson, Managing Director, Mazda Motors UK, said: I’m really excited about the new MX-30 R-EV joining our electrified line-up in the UK this summer. A great example of Mazda’s challenger spirit, thanks to its unique technological approach, it’s a car that’s the perfect solution for customers who want an electric car for everyday usage but the flexibility to undertake longer journeys without the reliance on charging infrastructure. With the option to choose either the pure electric MX-30 or the new R-EV version depending on their needs, our customers now have even more choice. Adding, “whichever version they choose they get the same seamless electric drive experience, engaging handling and first-class cabin, which features unique materials and premium design. It’s the latest example of how Mazda’s Multi Solution Approach ensures we have cars to suit all our customer’s needs by improving environmental performance with a combination of electrification and clever internal combustion engine technologies”. With the Mazda MX-30 e-Skyactiv EV on sale and in UK dealerships now, the Mazda MX-30 e-Skyactiv R-EV is available to order now, with the first UK cars due to arrive this summer.
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