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Post by c64 on May 10, 2014 16:55:01 GMT
Ok, so, I am going to re-ask a question, because I dont understand the answer.... Putting oil in a two stroke fuel. I know it lubricates "Something", but that something is not the problem, its the fact it has to lubricate anything at all. We are now modern, we have investigated may things, yet we cant make a two stroke engine that self lubricates without having to burn the oil to pass it through the combustion chamber with Total Loss?.... (as it in goes out the exhaust) Cannot we make bits of engine that dont need constant lubrication?... A 2-stroke engine is lacking the two strokes that replace the exhaust gasses with fresh air or an air/fuel mixture. The trick is that when the piston is all the way down after the work stroke, there are two holes in the side of the cylinder which were blocked by the piston during compression and work stroke. By blowing pressurized air into one hole, the exhaust gasses are replaced with fresh air. That's the major advantage of 2-stroke engines, you get a work stroke every revolution and you don't need a camshaft and valves. The cylinder and piston act as the valves. This means no moving parts other than the piston and the crankshaft so those 2-stroke engines can run a lot faster. What makes a 4-stroke blow up from RPM are usually the valve system which can't keep up and/or becomes bent. Without all those parts, there is no reason to include circulating oil systems and you can run the system with a lot more RPM. So in theory, you get the same work out of half of the amount of cylinders. In reality, you don't but leaving all the other stuff out like valves and oil pumps, you can have more displacement in the same engine size and even less weight More RPM also helps to get more power per pound out of an engine. In case of a chainsaw or other motortools, you don't want to handle more weight than necessary. So the problem is how to pressurize the air to make the engine accept it. You could attach a compressor driven by a belt, then you have a 2-stroke which can have an oil supply like a 4-stroke has. But in case of smaller engines, the blower is almost bulkier than just adding twice as much cylinders and make it a 4-stroke. So the trick is to use the other side of the piston like a bicycle pump compressing the air. A one-way valve makes sure that the crank case can only draw in air. And a grove in the cylinder wall allows the pressure to enter the work side of the cylinder when the piston is all the way down. The Bulldog engine drips oil on top of the crankshaft which will collect at the bottom of the crank shaft eventually where there is a mechanism which bleeds a limited volume of oil (or air) back into the lubrication oil storage tank. The crank case can't be filled with oil or the splashing oil would enter the cylinder. This engine just drips some oil in and makes sure there is not too much of oil around so it won't be burned. Only some vapors are drawn in but not enough to make the engine missfire. Like with all 2-stroke diesel engines, the crank case handles plain air, the fuel is injected indirectly into the cylinder. In early stationary engines, the lube oil is just dripped onto the parts and lost. "Total loss lubrication systems" were standard for steam engines and some early internal combustion engines. A 2-stroke gasoline engine has a big problem. Gasoline removes oil, that's why you use gasoline for cleaning purposes, especially for grease and oil. And since the fuel is added by a carburettor which works with a vacuum, you can't do that with the pressurized air from the crank case. So the gasoline must enter the crank case where it would void all attempts of lubrication. There are only 2 methods to fix this problem. Either using a direct injection which is highly complicated and demands a lot of expensive and delicate gear (even most modern cars don't use direct injection) or saturating the gas with oil to a point where it can't accept any more oil. This happens at a mixing ratio of below 1:50. So 1:50 makes sure that there is some basic lubrication present using modern materials. Old 2-stroke engines had to be run with 1:25, more oil than the gasoline can handle so there is plenty of oil condensing everywhere inside the engine for proper lubrication. Of course you could simply use a separate compressor between the carburettor and the engine so you can fill the crank case with oil again. But this adds a lot of weight and costs more money and a volatile fuel/air mix under pressure can explode so the extra system needs to be real tough in case of an explosion adding even more weight, bulk and costs. The crank case must be sturdy anyway and it also pressurizes at the correct moment right before the cylinder will absorb the pressure. And even if the mix will explode, there is either no pressure so the explosion is very weak or the blast goes into the cylinder which is designed to handle such things. So you need to burn oil with a gasoline 2-stroke or there is no point in using a 2-stroke in the first place. But the real "environmental sin" isn't the oil. People use castor oil or veggie oils for 2-strokes since decades since castor oil has much better lubrication abilities than mineral oil anyway. And burning castor oil isn't bad for the environment at all. The problem is flushing the cylinder. Remember, intake and outlet of the cylinder are open at the very same time! Either you replace just some exhaust gasses or fresh fuel/air mixture will escape right through the tailpipe. So part of the fuel you use for a gasoline 2-stroke engine will always be blown down the exhaust pipe unused. And that's why 2-stroke engined cars are sooooooo much fun. Just take a piece of metal pipe, a common butane lighter and you can drive like Batman! And that's what kills a catalytic converter and is real bad for the environment - not really the oil!
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Post by c64 on May 10, 2014 17:10:22 GMT
so... how much does the engine weigh? my chain saw, for example, weighs 10 pounds and develops 10.9 horsepower. (well probably weighs 12 because of the oversized bar) No idea, but it's much more efficient than this one here: And it's NOT a "hit and miss" engine, it can't be. The crankcase design screams "2-stroke" and the smoke says "Diesel". Hit and miss are always 4-stroke gasoline engines. There is no point for "hit and miss" which is a method to substitute a throttle flap - a true Diesel has no throttle! Even the original design by Rudolf Diesel himself just decreased the amount of injection when the engine becomes too fast.
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Post by c64 on May 10, 2014 17:20:39 GMT
P.S.: The extra engines are not necessary to operate such an engine. I think they are just used to be able to make it more "portable". The compressed air required for starting was usually stored in huge compressed air vessels in the engine room filled by a compressor attached to the engine. Also the coolant and lubrication pumps are directly connected to the engine. There is no point in cooling an engine which doesn't run. Lubrication IS a problem when starting the engine but those usually ran 24/7. Here is a link to the "power supply" of an old long wave radio station in Austria: www.hcrs.at/BSBGDIES.HTMA bit more modern, 4-stroke but the same idea how to use engines like this caliber.
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Post by the light works on May 10, 2014 17:22:47 GMT
a carburator operates by venturi, not vacuum. it is airflow across the jets that draws and atomizes the fuel, just like a perfume atomizer.
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Post by the light works on May 10, 2014 17:29:17 GMT
so... how much does the engine weigh? my chain saw, for example, weighs 10 pounds and develops 10.9 horsepower. (well probably weighs 12 because of the oversized bar) No idea, but it's much more efficient than this one here: And it's NOT a "hit and miss" engine, it can't be. The crankcase design screams "2-stroke" and the smoke says "Diesel". Hit and miss are always 4-stroke gasoline engines. There is no point for "hit and miss" which is a method to substitute a throttle flap - a true Diesel has no throttle! Even the original design by Rudolf Diesel himself just decreased the amount of injection when the engine becomes too fast. the "it runs on diesel fuel caption" is also an indicator. and no, the two pony engines are to compensate for the fact that the main engine is not driving anything at all. they may have used a pony engine to start it when it was in use, but everything else would be self sustaining.
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Post by c64 on May 10, 2014 17:42:00 GMT
a carburator operates by venturi, not vacuum. it is airflow across the jets that draws and atomizes the fuel, just like a perfume atomizer. Correct, but in order to get the gas flow in, you need a vacuum "Somewhere" in the system. An overpressure would just blow air into the gas tank instead of drawing fuel. True, the fuel is drawn by the venturi effect, but this causes an under-pressure ("vacuum") in the fuel to draw it in. The choke feature (now automatic on modern carburettor systems) just "chokes" the carburettor intake making the engine create a vacuum inside of the carburettor to s*** more fuel than normal. An overpressure would the the "anti-choke". The Renault R16 had a pretty clever feature. There is a part that looks like a frying pan covering the air filter. Instead of a handle, it has a long pipe. In summer, you install it pointing it to the front of the car for cold air. In winter, you turn it 90° to draw warm air from behind the engine. The clever part is, that in the winter configuration the pipe ends just at the edge of the hood on the driver's side. Also this pipe has holes drilled over its entire length. This can be used to "super choke" the engine during real cold mornings. This is not part of the instruction manual, but when the car refuses to start, just crank down the driver's side window, pull the hood lever, lift the hood with your left hand and reach in to cover the pipe, then turn the key with your right hand. The holes in the pipe are just right to add a minimum of air and the engine will start, no matter how cold it is. And you don't even have to unbuckle doing this!
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Post by the light works on May 10, 2014 18:09:18 GMT
this is a nice old educational film - American made, but it gives due credit to Diesel. it also shows why there is no such thing as a simple lightweight diesel
(its also somewhat off-topic for the free piston principle.)
here is one group's publicity video for their free piston system - note it is from 2005.
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Post by the light works on May 10, 2014 18:12:07 GMT
a carburator operates by venturi, not vacuum. it is airflow across the jets that draws and atomizes the fuel, just like a perfume atomizer. Correct, but in order to get the gas flow in, you need a vacuum "Somewhere" in the system. An overpressure would just blow air into the gas tank instead of drawing fuel. True, the fuel is drawn by the venturi effect, but this causes an under-pressure ("vacuum") in the fuel to draw it in. The choke feature (now automatic on modern carburettor systems) just "chokes" the carburettor intake making the engine create a vacuum inside of the carburettor to s*** more fuel than normal. An overpressure would the the "anti-choke". The Renault R16 had a pretty clever feature. There is a part that looks like a frying pan covering the air filter. Instead of a handle, it has a long pipe. In summer, you install it pointing it to the front of the car for cold air. In winter, you turn it 90° to draw warm air from behind the engine. The clever part is, that in the winter configuration the pipe ends just at the edge of the hood on the driver's side. Also this pipe has holes drilled over its entire length. This can be used to "super choke" the engine during real cold mornings. This is not part of the instruction manual, but when the car refuses to start, just crank down the driver's side window, pull the hood lever, lift the hood with your left hand and reach in to cover the pipe, then turn the key with your right hand. The holes in the pipe are just right to add a minimum of air and the engine will start, no matter how cold it is. And you don't even have to unbuckle doing this! this is true - and in supercharged gas engines, the supercharger is after the carburetors for that reason.
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Post by silverdragon on May 11, 2014 10:21:43 GMT
Ok, so, I am going to re-ask a question, because I dont understand the answer.... Putting oil in a two stroke fuel. I know it lubricates "Something", but that something is not the problem, its the fact it has to lubricate anything at all. We are now modern, we have investigated may things, yet we cant make a two stroke engine that self lubricates without having to burn the oil to pass it through the combustion chamber with Total Loss?.... (as it in goes out the exhaust) Cannot we make bits of engine that dont need constant lubrication?... a simple two stroke - aka chainsaw engine, uses the crankcase as a supercharger. therefore, there is no crankcase oil, and as I am sure you know, gasoline is an excellent solvent for cleaning oil off of metal parts. so you could certainly make a two stroke engine with a blower and an oil filled crankcase - at the expense of cutting the horsepower per pound in half. but you can't make a permanently lubricated crankcase with a constant flow of fuel-air mix through it. Ok, so here is an idea, how about we get modern and fuel inject the thing?.... If the fuel is ONLY getting into the combustion chamber, you could have your oil in the crank case?...
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Post by silverdragon on May 11, 2014 10:26:15 GMT
Just for information, I know first hand by taking them apart how a 2-stroke engine works, I have ridden a few "Back in the day", so I am asking questions to get people thinking, and perhaps inventing. Who says we have to end the world still using "Conventional" 2 stroke engines that have not been improved since 1960.
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Post by c64 on May 11, 2014 11:44:07 GMT
it also shows why there is no such thing as a simple lightweight diesel True, modern Diesel engines are not "simple" like the classic Diesel engines used to be. But the same is true for gas engines. Just look at a modern, EPA approved carburettor! I've worked for a construction machine company which sells machines all over the world. The US market don't accept the diesel engines used for the European market, those machines were equipped by highly expensive and very complex Honda gas engines. The EU machines are equipped with a Hatz Diesel engine which is much more compact, has more power and is much more sturdier AND it is cheaper. The US gasoline versions of the machines are heavier and have to be manually started. The diesel versions are lighter AND have electric starters. The smaller and lighter Diesel engine leaves room for a battery and the machine is still lighter even with a "box of lead" next to the engine. The main difference is that the Diesel engine doesn't need a catalytic converter and is a 2-stroke engine. Half the amount of cylinders, no valve mechanism, just the complex direct fuel injection which isn't that expensive and bulky thanks to precision micro-mechanics. Most people think that a Diesel engine is big, loud, shakes and shivers and prevents a smooth ride. If you want to see an awesome engine concept, look at this: www.neander-motors.com/Welcome.htmlThe compensating masses concept of this engine makes it run very smooth. The 1-cylinder version runs a lot smoother than a 4-cylinder gasoline engine. A 2-calinder motorcycle engine runs almost as smooth as an electric motor!
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Post by silverdragon on May 11, 2014 11:59:42 GMT
I challenge them. I will take the same car, either a certain Mercedes or BMW equivalent, one fitted as Petrol, one fitted as oil-burner, and see if they can tell which is which from a ride in the back seat.
Modern diesel are not the same as old clunkers, I have been in one that has been improved and run on rally stages, the basic engine before they did the upgrades is educational to anyone who has not experienced modern diesels as its quiet smooth and has a LOT of power, which it delivers very smoothly and equally along its entire range.
The reason I dont run a diesel at the moment is purely that the same car attracts a huge extra value price tag, that frankly is not worth the saving in fuel costs, nor is it worth the extra in other costs. (Extra insurance for larger engines that go on CC's and pay no respect to fuel) Diesel are not worth the extra investment, as you do not recover the costs over the time you own it. And they are not "More reliable" any more... The Toyota engine I run will go round the clock more times that mickeys left hand if serviced properly without even the slightest concerns. As long as it is not abused. But then you can say the same for any engine?.....
I can get a better car in petrol for the same money as a just passable diesel.
But as a gift, I would gladly accept diesel power.
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Post by the light works on May 11, 2014 14:23:20 GMT
a simple two stroke - aka chainsaw engine, uses the crankcase as a supercharger. therefore, there is no crankcase oil, and as I am sure you know, gasoline is an excellent solvent for cleaning oil off of metal parts. so you could certainly make a two stroke engine with a blower and an oil filled crankcase - at the expense of cutting the horsepower per pound in half. but you can't make a permanently lubricated crankcase with a constant flow of fuel-air mix through it. Ok, so here is an idea, how about we get modern and fuel inject the thing?.... If the fuel is ONLY getting into the combustion chamber, you could have your oil in the crank case?... absolutely, and that is how Cummins and Detroit diesels are put together. the old detroits didn't even have an intake valve. the piston uncovered the inlet ports on the downstroke. - but it has to have a supercharger of some kind at that point.
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Post by the light works on May 11, 2014 14:32:40 GMT
it also shows why there is no such thing as a simple lightweight diesel True, modern Diesel engines are not "simple" like the classic Diesel engines used to be. But the same is true for gas engines. Just look at a modern, EPA approved carburettor! I've worked for a construction machine company which sells machines all over the world. The US market don't accept the diesel engines used for the European market, those machines were equipped by highly expensive and very complex Honda gas engines. The EU machines are equipped with a Hatz Diesel engine which is much more compact, has more power and is much more sturdier AND it is cheaper. The US gasoline versions of the machines are heavier and have to be manually started. The diesel versions are lighter AND have electric starters. The smaller and lighter Diesel engine leaves room for a battery and the machine is still lighter even with a "box of lead" next to the engine. The main difference is that the Diesel engine doesn't need a catalytic converter and is a 2-stroke engine. Half the amount of cylinders, no valve mechanism, just the complex direct fuel injection which isn't that expensive and bulky thanks to precision micro-mechanics. Most people think that a Diesel engine is big, loud, shakes and shivers and prevents a smooth ride. If you want to see an awesome engine concept, look at this: www.neander-motors.com/Welcome.htmlThe compensating masses concept of this engine makes it run very smooth. The 1-cylinder version runs a lot smoother than a 4-cylinder gasoline engine. A 2-calinder motorcycle engine runs almost as smooth as an electric motor! Diesels have never been simple in the way that gas engines can be simple. they are inherently higher tech than the simplest gasoline can be - yet high tech gasoline engines can have a higher degree of improvement than higher tech diesels. as for the interpretation of Diesels, the only Diesels in America which still have that reputation are Cummins - for some reason Cummins likes making rod-knockers for their passenger vehicle engines and rednecks like driving Cummins engines with bad mufflers. the only complaint most people have about diesels is the smell. (of both the fuel and the exhaust)
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Post by GTCGreg on May 11, 2014 16:26:54 GMT
Diesels have never been simple in the way that gas engines can be simple. they are inherently higher tech than the simplest gasoline can be - yet high tech gasoline engines can have a higher degree of improvement than higher tech diesels. as for the interpretation of Diesels, the only Diesels in America which still have that reputation are Cummins - for some reason Cummins likes making rod-knockers for their passenger vehicle engines and rednecks like driving Cummins engines with bad mufflers. the only complaint most people have about diesels is the smell. (of both the fuel and the exhaust) Have you driven a Ford lately? Or even not so lately. When it comes to noise, smell, vibration and general nastiness, their small Diesels can hold their own against anyone. And as far as simplicity goes, what about a Diesel model airplane engine. Only two moving parts. The crank and the piston. You can't get much simpler than that. It's basically a nitro glow plug engine with a high compression head and no glow plug. coxengines.ca/cox-.049-rc-diesel-engine.html
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Post by c64 on May 11, 2014 17:54:16 GMT
When it comes to noise, smell, vibration and general nastiness, their small Diesels can hold their own against anyone. The most "nasty" Diesel powered vehicle I had the opportunity to test drive is this one: It has more power than it can possible handle, Deutz had built their largest engine into about their smallest farming tractor. 16 liter V-12, the same as used for the most powerful semi truck about 50 years ago, the Magirus Deutz Uranus With 250 HP, this one was the most powerful Diesel powered production vehicle. And the tiny tractor from above could even be bought with a modified engine developing up to 350 HP - but lousy MPG. You need to refuel it so often, that you are much faster by walking. And nowadays, a Diesel engine with similar HP rating fits into a common middle class car. My brother-in-law owns an Audi A6 with a Diesel with more than 200 HP. And that isn't the strongest Diesel engine you can put into this car.
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Post by the light works on May 12, 2014 3:24:53 GMT
Diesels have never been simple in the way that gas engines can be simple. they are inherently higher tech than the simplest gasoline can be - yet high tech gasoline engines can have a higher degree of improvement than higher tech diesels. as for the interpretation of Diesels, the only Diesels in America which still have that reputation are Cummins - for some reason Cummins likes making rod-knockers for their passenger vehicle engines and rednecks like driving Cummins engines with bad mufflers. the only complaint most people have about diesels is the smell. (of both the fuel and the exhaust) Have you driven a Ford lately? Or even not so lately. When it comes to noise, smell, vibration and general nastiness, their small Diesels can hold their own against anyone. And as far as simplicity goes, what about a Diesel model airplane engine. Only two moving parts. The crank and the piston. You can't get much simpler than that. It's basically a nitro glow plug engine with a high compression head and no glow plug. coxengines.ca/cox-.049-rc-diesel-engine.htmlmy quick attack is a Ford, the other two quick attacks are Chevys. the bigger apparatus run Cummins truck engines (much quieter than Dodge Cummins engines) my old tender was a "screaming" Jimmy - those were called screaming jimmys for a reason. not sure whether it was the blower or what that made the distinctive scream - but at around 2000 RPM it went from a roar to a tone. the others are all pretty quiet. tried to find you a clip with audio of one at full scream, but didn't find any good ones.
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Post by c64 on May 12, 2014 11:51:04 GMT
The old air cooled Magirus Deutz trucks also made a pretty weird noise at high RPM due to the huge cooling blower. But the crude gearbox made even more screaming sounds, especially in low 4x4 modes. Back to the "free piston engine". In the good old days, construction site compressors usually were built like this: Attachment DeletedJust a straight 6 truck engine with some modified cylinder heads and a different crankshaft. 3 cylinders are used as the compressor. Simple, cheap and very powerful. But those are not used any more for two reasons. First of all, the "Diesel" side of the engine has too much displacement for the compressor side of the engine. It is very inefficient. But the worst part is that exhaust gasses are pressed into the compressor side so you have exhaust fumes (and lots of engine oil) in your compressed air. So this very simple and practical design is now discarded due to health, economic and especially environmental reasons. You need 3 compressed air cylinders to generate a more or less constant air flow. The "free piston engine" can't do this with only 1 cylinder and you would need 3 cylinders in sync for a decent compressor with a good flow. And for electricity, it will break the magnets by "hammering" and it can't have much efficiency since the gap between magnet and coil steals energy. The piston must move with a very high precision to keep the gap down but on a piston without anything else, there is nothing that can guarantee a precise movement. Also the heat of the engine will heat up the coils and they increase their electric resistance. You need to prevent that heat can affect the generator and a powerful fan to prevent the generator from heating up itself. How do you drive the fan with the "free piston"? And how do you insulate the coils from the engine heat? How do you cool the engine anyway without a blower? Use an electric one?
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Post by the light works on May 12, 2014 14:13:24 GMT
The old air cooled Magirus Deutz trucks also made a pretty weird noise at high RPM due to the huge cooling blower. But the crude gearbox made even more screaming sounds, especially in low 4x4 modes. Back to the "free piston engine". In the good old days, construction site compressors usually were built like this: View AttachmentJust a straight 6 truck engine with some modified cylinder heads and a different crankshaft. 3 cylinders are used as the compressor. Simple, cheap and very powerful. But those are not used any more for two reasons. First of all, the "Diesel" side of the engine has too much displacement for the compressor side of the engine. It is very inefficient. But the worst part is that exhaust gasses are pressed into the compressor side so you have exhaust fumes (and lots of engine oil) in your compressed air. So this very simple and practical design is now discarded due to health, economic and especially environmental reasons. You need 3 compressed air cylinders to generate a more or less constant air flow. The "free piston engine" can't do this with only 1 cylinder and you would need 3 cylinders in sync for a decent compressor with a good flow. And for electricity, it will break the magnets by "hammering" and it can't have much efficiency since the gap between magnet and coil steals energy. The piston must move with a very high precision to keep the gap down but on a piston without anything else, there is nothing that can guarantee a precise movement. Also the heat of the engine will heat up the coils and they increase their electric resistance. You need to prevent that heat can affect the generator and a powerful fan to prevent the generator from heating up itself. How do you drive the fan with the "free piston"? And how do you insulate the coils from the engine heat? How do you cool the engine anyway without a blower? Use an electric one? if you watch the video I posted you will see that the "free piston" just means it moves the magnet directly, instead of turning a crankshaft that turns a generator head. this reduces the overall size of the equipment significantly. not sure why you are trying to turn this into an air compressor - there really is no conversion there. and it would use electric pumps to drive the cooling system and intake blower and solenoids to run the valvetrain. the company that made the video designed the engine to be a hybrid car engine, and you would gang as many cylinders as you needed, just like a conventional engine. a small car might only need a one cylinder engine (1 cylinder = two pistons) a truck might run 4 cylinders or more - but only use as many cylinders as were needed to maintain operating power, unlike a conventional engine which must turn the whole engine to work.
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Post by the light works on May 12, 2014 16:48:58 GMT
Diesels have never been simple in the way that gas engines can be simple. they are inherently higher tech than the simplest gasoline can be - yet high tech gasoline engines can have a higher degree of improvement than higher tech diesels. as for the interpretation of Diesels, the only Diesels in America which still have that reputation are Cummins - for some reason Cummins likes making rod-knockers for their passenger vehicle engines and rednecks like driving Cummins engines with bad mufflers. the only complaint most people have about diesels is the smell. (of both the fuel and the exhaust) Have you driven a Ford lately? Or even not so lately. When it comes to noise, smell, vibration and general nastiness, their small Diesels can hold their own against anyone. And as far as simplicity goes, what about a Diesel model airplane engine. Only two moving parts. The crank and the piston. You can't get much simpler than that. It's basically a nitro glow plug engine with a high compression head and no glow plug. coxengines.ca/cox-.049-rc-diesel-engine.htmltrue, I had forgotten that a standard Cox engine is essentially a hot bulb engine.
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