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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
"Lotus Engineering is currently developing an engine concept called
the OMNIVORE together with the Queen’s University Belfast and Jaguar Cars Ltd. The OMNIVORE research engine features a variable compression ratio, direct injection and a two-stroke operating cycle. It will run on a mix of petrol and alcohol." So says the press release from lotus regarding the engine. They are trying to develop the engine to run on all three fuels- diesel, gas or alky- dunno if they intend it to run on any mix of the 3- that might prove problematic. Trying to get my head wrapped around how they are going to manage all the stuff to get the beast to run on all the different fuels. Do you think that since they can inject the fuel directly, they are going to be pressure lubing the cylinder walls? It's a 2 stroke so I'm resuming that it could still have a poppet valve as opposed to the port exhaust- that would allow some variability to the timing. Now, as to the variable compression ratio...how do you think they intend to implement that? Pat |
#2
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
patrick wrote:
"Lotus Engineering is currently developing an engine concept called the OMNIVORE together with the Queen’s University Belfast and Jaguar Cars Ltd. The OMNIVORE research engine features a variable compression ratio, direct injection and a two-stroke operating cycle. It will run on a mix of petrol and alcohol." Cool - I wanna play too... "DeSoto Solar is currently developing an engine whose only moving parts are air and water, and which does not require any kind of fuel - it runs on sunshine only. It's not intended to compete with the Lotus OMNIVORE, but current indications are that a typical engine service life can be measured in centuries." Now I feel better. I can even offer a link. :-) -- Morris Dovey DeSoto Solar DeSoto, Iowa USA http://www.iedu.com/DeSoto/Projects/Stirling/ |
#3
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
"patrick" wrote in message ... "Lotus Engineering is currently developing an engine concept called the OMNIVORE together with the Queen’s University Belfast and Jaguar Cars Ltd. The OMNIVORE research engine features a variable compression ratio, direct injection and a two-stroke operating cycle. It will run on a mix of petrol and alcohol." So says the press release from lotus regarding the engine. They are trying to develop the engine to run on all three fuels- diesel, gas or alky- dunno if they intend it to run on any mix of the 3- that might prove problematic. Trying to get my head wrapped around how they are going to manage all the stuff to get the beast to run on all the different fuels. Do you think that since they can inject the fuel directly, they are going to be pressure lubing the cylinder walls? It's a 2 stroke so I'm resuming that it could still have a poppet valve as opposed to the port exhaust- that would allow some variability to the timing. Now, as to the variable compression ratio...how do you think they intend to implement that? Pat ============================================ Most of the major carmakers around the world are working on VCR (variable compression ratio) engines. Nissan uses a multi-link connecting rod system. A German engineering firm has an eccentric-crankshaft system. Teledyne-Continental had a variable-piston research VCR roughly 20 years ago. And there are variations on another one or two themes. The Lotus project is just a single-cylinder research engine for now. I think what's caught so much attention is the combination of the 2-stroke basic cycle, and a fine job of hyping the government and other connections that are involved. It's a slick idea. We'll see if this one gets anywhere. -- Ed Huntress |
#4
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
"Ed Huntress" wrote in message ... "patrick" wrote in message ... "Lotus Engineering is currently developing an engine concept called the OMNIVORE together with the Queen's University Belfast and Jaguar Cars Ltd. The OMNIVORE research engine features a variable compression ratio, direct injection and a two-stroke operating cycle. It will run on a mix of petrol and alcohol." So says the press release from lotus regarding the engine. They are trying to develop the engine to run on all three fuels- diesel, gas or alky- dunno if they intend it to run on any mix of the 3- that might prove problematic. Trying to get my head wrapped around how they are going to manage all the stuff to get the beast to run on all the different fuels. Do you think that since they can inject the fuel directly, they are going to be pressure lubing the cylinder walls? It's a 2 stroke so I'm resuming that it could still have a poppet valve as opposed to the port exhaust- that would allow some variability to the timing. Now, as to the variable compression ratio...how do you think they intend to implement that? Pat ============================================ Most of the major carmakers around the world are working on VCR (variable compression ratio) engines. Nissan uses a multi-link connecting rod system. A German engineering firm has an eccentric-crankshaft system. Teledyne-Continental had a variable-piston research VCR roughly 20 years ago. And there are variations on another one or two themes. The Lotus project is just a single-cylinder research engine for now. I think what's caught so much attention is the combination of the 2-stroke basic cycle, and a fine job of hyping the government and other connections that are involved. It's a slick idea. We'll see if this one gets anywhere. -- Ed Huntress A couple years back, someone had a working prototype with an electric jackscrew that altered the crank relationship to the top of the cylinder, another used hydraulic pressure to effect the same result One of my customers is working with engineers at WVU on a low-compression diesel-fueled engine. It can use modern fuel-injection goodies, or possibly even a carburetor. The concept is pretty sweet. It is very practical, very simple, no unusual parts or machining involved. No high pressure injection pump with close tolerances. Our military is searching for practical small engines that run on diesel, and that's what is driving this project. Think diesel-fueled powerplant for tiny little drone aircraft. |
#5
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
On Aug 14, 3:48 pm, "Jon" wrote:
"Ed Huntress" wrote in message ... "patrick" wrote in message ... "Lotus Engineering is currently developing an engine concept called the OMNIVORE together with the Queen's University Belfast and Jaguar Cars Ltd. The OMNIVORE research engine features a variable compression ratio, direct injection and a two-stroke operating cycle. It will run on a mix of petrol and alcohol." So says the press release from lotus regarding the engine. They are trying to develop the engine to run on all three fuels- diesel, gas or alky- dunno if they intend it to run on any mix of the 3- that might prove problematic. Trying to get my head wrapped around how they are going to manage all the stuff to get the beast to run on all the different fuels. Do you think that since they can inject the fuel directly, they are going to be pressure lubing the cylinder walls? It's a 2 stroke so I'm resuming that it could still have a poppet valve as opposed to the port exhaust- that would allow some variability to the timing. Now, as to the variable compression ratio...how do you think they intend to implement that? Pat ============================================ Most of the major carmakers around the world are working on VCR (variable compression ratio) engines. Nissan uses a multi-link connecting rod system. A German engineering firm has an eccentric-crankshaft system. Teledyne-Continental had a variable-piston research VCR roughly 20 years ago. And there are variations on another one or two themes. The Lotus project is just a single-cylinder research engine for now. I think what's caught so much attention is the combination of the 2-stroke basic cycle, and a fine job of hyping the government and other connections that are involved. It's a slick idea. We'll see if this one gets anywhere. -- Ed Huntress A couple years back, someone had a working prototype with an electric jackscrew that altered the crank relationship to the top of the cylinder, another used hydraulic pressure to effect the same result One of my customers is working with engineers at WVU on a low-compression diesel-fueled engine. It can use modern fuel-injection goodies, or possibly even a carburetor. The concept is pretty sweet. It is very practical, very simple, no unusual parts or machining involved. No high pressure injection pump with close tolerances. Our military is searching for practical small engines that run on diesel, and that's what is driving this project. Think diesel-fueled powerplant for tiny little drone aircraft. How small? There's already the diesel-power military bike based on the kawasaki KLR650 (all new engine), its about 650-700ccs I think. Dave |
#6
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
Morris Dovey wrote:
patrick wrote: "Lotus Engineering is currently developing an engine concept called the OMNIVORE together with the Queen’s University Belfast and Jaguar Cars Ltd. The OMNIVORE research engine features a variable compression ratio, direct injection and a two-stroke operating cycle. It will run on a mix of petrol and alcohol." Cool - I wanna play too... "DeSoto Solar is currently developing an engine whose only moving parts are air and water, and which does not require any kind of fuel - it runs on sunshine only. It's not intended to compete with the Lotus OMNIVORE, but current indications are that a typical engine service life can be measured in centuries." Now I feel better. I can even offer a link. :-) Only the first link worked and none of the videos. I'm intrested. See if you can find out what is wrong. ...lew... |
#7
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
On Thu, 14 Aug 2008 14:03:10 -0600, with neither quill nor qualm, Lew
Hartswick quickly quoth: Morris Dovey wrote: patrick wrote: "Lotus Engineering is currently developing an engine concept called the OMNIVORE together with the Queen’s University Belfast and Jaguar Cars Ltd. The OMNIVORE research engine features a variable compression ratio, direct injection and a two-stroke operating cycle. It will run on a mix of petrol and alcohol." Cool - I wanna play too... "DeSoto Solar is currently developing an engine whose only moving parts are air and water, and which does not require any kind of fuel - it runs on sunshine only. It's not intended to compete with the Lotus OMNIVORE, but current indications are that a typical engine service life can be measured in centuries." Now I feel better. I can even offer a link. :-) Only the first link worked and none of the videos. I'm intrested. See if you can find out what is wrong. Most likely answer: Loose nut behind the keyboard in Albu, lew. (It just now worked fine for me, and I've been playing games with Logitech's Mouseware and my DSL modem for a couple days now.) -- Challenges are gifts that force us to search for a new center of gravity. Don't fight them. Just find a different way to stand. -- Oprah Winfrey |
#8
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
Lew Hartswick wrote:
Only the first link worked and none of the videos. I'm intrested. See if you can find out what is wrong. Sorry, Lew. The links (and the one video) work for me - I think you may have caught the server in a busy moment (that video is short, but is still sizable). Please give it another try... -- Morris Dovey DeSoto Solar DeSoto, Iowa USA http://www.iedu.com/DeSoto/ |
#9
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
wrote in message ... On Aug 14, 3:48 pm, "Jon" wrote: "Ed Huntress" wrote in message ... "patrick" wrote in message ... "Lotus Engineering is currently developing an engine concept called the OMNIVORE together with the Queen's University Belfast and Jaguar Cars Ltd. The OMNIVORE research engine features a variable compression ratio, direct injection and a two-stroke operating cycle. It will run on a mix of petrol and alcohol." So says the press release from lotus regarding the engine. They are trying to develop the engine to run on all three fuels- diesel, gas or alky- dunno if they intend it to run on any mix of the 3- that might prove problematic. Trying to get my head wrapped around how they are going to manage all the stuff to get the beast to run on all the different fuels. Do you think that since they can inject the fuel directly, they are going to be pressure lubing the cylinder walls? It's a 2 stroke so I'm resuming that it could still have a poppet valve as opposed to the port exhaust- that would allow some variability to the timing. Now, as to the variable compression ratio...how do you think they intend to implement that? Pat ============================================ Most of the major carmakers around the world are working on VCR (variable compression ratio) engines. Nissan uses a multi-link connecting rod system. A German engineering firm has an eccentric-crankshaft system. Teledyne-Continental had a variable-piston research VCR roughly 20 years ago. And there are variations on another one or two themes. The Lotus project is just a single-cylinder research engine for now. I think what's caught so much attention is the combination of the 2-stroke basic cycle, and a fine job of hyping the government and other connections that are involved. It's a slick idea. We'll see if this one gets anywhere. -- Ed Huntress A couple years back, someone had a working prototype with an electric jackscrew that altered the crank relationship to the top of the cylinder, another used hydraulic pressure to effect the same result One of my customers is working with engineers at WVU on a low-compression diesel-fueled engine. It can use modern fuel-injection goodies, or possibly even a carburetor. The concept is pretty sweet. It is very practical, very simple, no unusual parts or machining involved. No high pressure injection pump with close tolerances. Our military is searching for practical small engines that run on diesel, and that's what is driving this project. Think diesel-fueled powerplant for tiny little drone aircraft. How small? There's already the diesel-power military bike based on the kawasaki KLR650 (all new engine), its about 650-700ccs I think. Dave small like 25-100cc |
#10
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
Larry Jaques wrote:
Most likely answer: Loose nut behind the keyboard in Albu, lew. I guess thats like the nut that holds the steering wheel on so many cars these days. :-) ...lew... |
#11
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
"Jon" wrote in message news:_bgpk.3$5C.2@trnddc02... wrote in message ... On Aug 14, 3:48 pm, "Jon" wrote: "Ed Huntress" wrote in message ... "patrick" wrote in message ... "Lotus Engineering is currently developing an engine concept called the OMNIVORE together with the Queen's University Belfast and Jaguar Cars Ltd. The OMNIVORE research engine features a variable compression ratio, direct injection and a two-stroke operating cycle. It will run on a mix of petrol and alcohol." So says the press release from lotus regarding the engine. They are trying to develop the engine to run on all three fuels- diesel, gas or alky- dunno if they intend it to run on any mix of the 3- that might prove problematic. Trying to get my head wrapped around how they are going to manage all the stuff to get the beast to run on all the different fuels. Do you think that since they can inject the fuel directly, they are going to be pressure lubing the cylinder walls? It's a 2 stroke so I'm resuming that it could still have a poppet valve as opposed to the port exhaust- that would allow some variability to the timing. Now, as to the variable compression ratio...how do you think they intend to implement that? Pat ============================================ Most of the major carmakers around the world are working on VCR (variable compression ratio) engines. Nissan uses a multi-link connecting rod system. A German engineering firm has an eccentric-crankshaft system. Teledyne-Continental had a variable-piston research VCR roughly 20 years ago. And there are variations on another one or two themes. The Lotus project is just a single-cylinder research engine for now. I think what's caught so much attention is the combination of the 2-stroke basic cycle, and a fine job of hyping the government and other connections that are involved. It's a slick idea. We'll see if this one gets anywhere. -- Ed Huntress A couple years back, someone had a working prototype with an electric jackscrew that altered the crank relationship to the top of the cylinder, another used hydraulic pressure to effect the same result One of my customers is working with engineers at WVU on a low-compression diesel-fueled engine. It can use modern fuel-injection goodies, or possibly even a carburetor. The concept is pretty sweet. It is very practical, very simple, no unusual parts or machining involved. No high pressure injection pump with close tolerances. Our military is searching for practical small engines that run on diesel, and that's what is driving this project. Think diesel-fueled powerplant for tiny little drone aircraft. How small? There's already the diesel-power military bike based on the kawasaki KLR650 (all new engine), its about 650-700ccs I think. Dave small like 25-100cc The general rule is that a true diesel, running on conventional diesel fuel, requires a minimum cylinder volume of something like 250 cc. That's because there's too much quenching at smaller volumes, in which the surface area/volume ratio is inversely related to volume. However, there is an incredible amount of research being done right now on compression ignition, and dual ignition with spark plugs and glow plugs. Go to the SAE site and search on "compression ignition." You'll get over 7,000 hits on SAE papers, the more recent of which are mostly about HCCI (homogeneous charge, compression ignition) and there are some on SACI (spark-assisted, stratified-charge). Everything you can think of is in play, including mixed fuels, mixed ignition, and more. There are free abstracts on most of the papers: www.sae.org You may be aware that model "diesels," which generally don't have injection and thus are not considered true diesels, use ether as a fuel and can be very small in displacement volume. Ether has a cetane rating of something like 82, so it's very easy to ignite with compression. -- Ed Huntress |
#12
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
"Ed Huntress" wrote in message ... "Jon" wrote in message news:_bgpk.3$5C.2@trnddc02... wrote in message ... On Aug 14, 3:48 pm, "Jon" wrote: "Ed Huntress" wrote in message ... "patrick" wrote in message ... "Lotus Engineering is currently developing an engine concept called the OMNIVORE together with the Queen's University Belfast and Jaguar Cars Ltd. The OMNIVORE research engine features a variable compression ratio, direct injection and a two-stroke operating cycle. It will run on a mix of petrol and alcohol." So says the press release from lotus regarding the engine. They are trying to develop the engine to run on all three fuels- diesel, gas or alky- dunno if they intend it to run on any mix of the 3- that might prove problematic. Trying to get my head wrapped around how they are going to manage all the stuff to get the beast to run on all the different fuels. Do you think that since they can inject the fuel directly, they are going to be pressure lubing the cylinder walls? It's a 2 stroke so I'm resuming that it could still have a poppet valve as opposed to the port exhaust- that would allow some variability to the timing. Now, as to the variable compression ratio...how do you think they intend to implement that? Pat ============================================ Most of the major carmakers around the world are working on VCR (variable compression ratio) engines. Nissan uses a multi-link connecting rod system. A German engineering firm has an eccentric-crankshaft system. Teledyne-Continental had a variable-piston research VCR roughly 20 years ago. And there are variations on another one or two themes. The Lotus project is just a single-cylinder research engine for now. I think what's caught so much attention is the combination of the 2-stroke basic cycle, and a fine job of hyping the government and other connections that are involved. It's a slick idea. We'll see if this one gets anywhere. -- Ed Huntress A couple years back, someone had a working prototype with an electric jackscrew that altered the crank relationship to the top of the cylinder, another used hydraulic pressure to effect the same result One of my customers is working with engineers at WVU on a low-compression diesel-fueled engine. It can use modern fuel-injection goodies, or possibly even a carburetor. The concept is pretty sweet. It is very practical, very simple, no unusual parts or machining involved. No high pressure injection pump with close tolerances. Our military is searching for practical small engines that run on diesel, and that's what is driving this project. Think diesel-fueled powerplant for tiny little drone aircraft. How small? There's already the diesel-power military bike based on the kawasaki KLR650 (all new engine), its about 650-700ccs I think. Dave small like 25-100cc The general rule is that a true diesel, running on conventional diesel fuel, requires a minimum cylinder volume of something like 250 cc. That's because there's too much quenching at smaller volumes, in which the surface area/volume ratio is inversely related to volume. However, there is an incredible amount of research being done right now on compression ignition, and dual ignition with spark plugs and glow plugs. Go to the SAE site and search on "compression ignition." You'll get over 7,000 hits on SAE papers, the more recent of which are mostly about HCCI (homogeneous charge, compression ignition) and there are some on SACI (spark-assisted, stratified-charge). Everything you can think of is in play, including mixed fuels, mixed ignition, and more. There are free abstracts on most of the papers: www.sae.org You may be aware that model "diesels," which generally don't have injection and thus are not considered true diesels, use ether as a fuel and can be very small in displacement volume. Ether has a cetane rating of something like 82, so it's very easy to ignite with compression. -- Ed Huntress Thanks for the info, Ed. You'll note my carefully chosen description "diesel-fueled." The end user doesn't really care how it is achieved, as long as the fuel is the same as the rest of their fleet uses. This is why kawasaki developed their diesel bike, to help the military machines achieve their goals of being "one-fuel" armies Find the market, fill the market. Sweet. =) |
#13
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
"Jon" wrote in message news:JGipk.4$UX.1@trnddc03... "Ed Huntress" wrote in message ... "Jon" wrote in message news:_bgpk.3$5C.2@trnddc02... wrote in message ... On Aug 14, 3:48 pm, "Jon" wrote: "Ed Huntress" wrote in message ... "patrick" wrote in message ... "Lotus Engineering is currently developing an engine concept called the OMNIVORE together with the Queen's University Belfast and Jaguar Cars Ltd. The OMNIVORE research engine features a variable compression ratio, direct injection and a two-stroke operating cycle. It will run on a mix of petrol and alcohol." So says the press release from lotus regarding the engine. They are trying to develop the engine to run on all three fuels- diesel, gas or alky- dunno if they intend it to run on any mix of the 3- that might prove problematic. Trying to get my head wrapped around how they are going to manage all the stuff to get the beast to run on all the different fuels. Do you think that since they can inject the fuel directly, they are going to be pressure lubing the cylinder walls? It's a 2 stroke so I'm resuming that it could still have a poppet valve as opposed to the port exhaust- that would allow some variability to the timing. Now, as to the variable compression ratio...how do you think they intend to implement that? Pat ============================================ Most of the major carmakers around the world are working on VCR (variable compression ratio) engines. Nissan uses a multi-link connecting rod system. A German engineering firm has an eccentric-crankshaft system. Teledyne-Continental had a variable-piston research VCR roughly 20 years ago. And there are variations on another one or two themes. The Lotus project is just a single-cylinder research engine for now. I think what's caught so much attention is the combination of the 2-stroke basic cycle, and a fine job of hyping the government and other connections that are involved. It's a slick idea. We'll see if this one gets anywhere. -- Ed Huntress A couple years back, someone had a working prototype with an electric jackscrew that altered the crank relationship to the top of the cylinder, another used hydraulic pressure to effect the same result One of my customers is working with engineers at WVU on a low-compression diesel-fueled engine. It can use modern fuel-injection goodies, or possibly even a carburetor. The concept is pretty sweet. It is very practical, very simple, no unusual parts or machining involved. No high pressure injection pump with close tolerances. Our military is searching for practical small engines that run on diesel, and that's what is driving this project. Think diesel-fueled powerplant for tiny little drone aircraft. How small? There's already the diesel-power military bike based on the kawasaki KLR650 (all new engine), its about 650-700ccs I think. Dave small like 25-100cc The general rule is that a true diesel, running on conventional diesel fuel, requires a minimum cylinder volume of something like 250 cc. That's because there's too much quenching at smaller volumes, in which the surface area/volume ratio is inversely related to volume. However, there is an incredible amount of research being done right now on compression ignition, and dual ignition with spark plugs and glow plugs. Go to the SAE site and search on "compression ignition." You'll get over 7,000 hits on SAE papers, the more recent of which are mostly about HCCI (homogeneous charge, compression ignition) and there are some on SACI (spark-assisted, stratified-charge). Everything you can think of is in play, including mixed fuels, mixed ignition, and more. There are free abstracts on most of the papers: www.sae.org You may be aware that model "diesels," which generally don't have injection and thus are not considered true diesels, use ether as a fuel and can be very small in displacement volume. Ether has a cetane rating of something like 82, so it's very easy to ignite with compression. -- Ed Huntress Thanks for the info, Ed. You'll note my carefully chosen description "diesel-fueled." The end user doesn't really care how it is achieved, as long as the fuel is the same as the rest of their fleet uses. This is why kawasaki developed their diesel bike, to help the military machines achieve their goals of being "one-fuel" armies Find the market, fill the market. Sweet. =) That's always a good idea. d8-) Well, dual-fuel spark-ignition engines, which warm up running gasoline and then switch to kerosene (and probably diesel fuel, although I'm not certain about that) have been around for most of a century. They were popular for use in pumping water and other utility jobs on farms, and for some low-specific-output applications in industry. It probably would take something fancier to get a decent power/weight ratio for small aircraft, but the concept is well-proven. -- Ed Huntress |
#14
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OT- 2 stroke-/ variable c/r, direct injection engine
On Fri, 15 Aug 2008 08:18:18 -0600, with neither quill nor qualm, Lew
Hartswick quickly quoth: Larry Jaques wrote: Most likely answer: Loose nut behind the keyboard in Albu, lew. I guess thats like the nut that holds the steering wheel on so many cars these days. :-) Yeah, the loose nuts holding a cell phone in one hand and a CD in the other, all while attempting to negotiate a curve. But you're not -that- bad. -- Challenges are gifts that force us to search for a new center of gravity. Don't fight them. Just find a different way to stand. -- Oprah Winfrey |
#15
Posted to rec.crafts.metalworking
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OT- 2 stroke-/ variable c/r, direct injection engine
On Aug 14, 12:23*pm, patrick wrote:
"Lotus Engineering is currently developing an engine concept called the OMNIVORE together with the Queen’s University Belfast and Jaguar Cars Ltd. The OMNIVORE research engine features a variable compression ratio, direct injection and a two-stroke operating cycle. It will run on a mix of petrol and alcohol." * So says the press release from lotus regarding the engine. They are trying to develop the engine to run on all three fuels- diesel, gas or alky- dunno if they intend it to run on any mix of the 3- that might prove problematic. Trying to get my head wrapped around how they are going to manage all the stuff to get the beast to run on all the different fuels. Do you think that since they can inject the fuel directly, they are going to be pressure lubing the cylinder walls? It's a 2 stroke so I'm resuming that it could still have a poppet valve as opposed to the port exhaust- that would allow some variability to the timing. Now, as to the variable compression ratio...how do you think they intend to implement that? Pat Variable compression ratio is nothing new, saw it in a '20s engine book. Getting it and all the rest of the laundry list to work with some kind of fuel economy will be the trick. The way it was implemented way back was there was an auxillary chamber off to the side of the head with a valve in between. High compression had the valve closed, low compression had it open. Was for use in gasoline/ kerosene dual-fuel engines. If you wanted continuously variable compression, I suppose you could put a plug in the auxillary chamber and use a jackscrew to move it back and forth. Two-strokes typically have great power to weight, but lousy fuel economy, emissions and oil consumption. Sounds to me like a funding fishing expedition, maybe trying to shake some "green" government cash loose. Stan |
#16
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OT- 2 stroke-/ variable c/r, direct injection engine
On Fri, 15 Aug 2008 13:18:00 -0400, "Ed Huntress"
wrote: "Jon" wrote in message news:JGipk.4$UX.1@trnddc03... "Ed Huntress" wrote in message ... "Jon" wrote in message news:_bgpk.3$5C.2@trnddc02... wrote in message ... On Aug 14, 3:48 pm, "Jon" wrote: "Ed Huntress" wrote in message ... "patrick" wrote in message ... "Lotus Engineering is currently developing an engine concept called the OMNIVORE together with the Queen's University Belfast and Jaguar Cars Ltd. The OMNIVORE research engine features a variable compression ratio, direct injection and a two-stroke operating cycle. It will run on a mix of petrol and alcohol." So says the press release from lotus regarding the engine. They are trying to develop the engine to run on all three fuels- diesel, gas or alky- dunno if they intend it to run on any mix of the 3- that might prove problematic. Trying to get my head wrapped around how they are going to manage all the stuff to get the beast to run on all the different fuels. Do you think that since they can inject the fuel directly, they are going to be pressure lubing the cylinder walls? It's a 2 stroke so I'm resuming that it could still have a poppet valve as opposed to the port exhaust- that would allow some variability to the timing. Now, as to the variable compression ratio...how do you think they intend to implement that? Pat ============================================ Most of the major carmakers around the world are working on VCR (variable compression ratio) engines. Nissan uses a multi-link connecting rod system. A German engineering firm has an eccentric-crankshaft system. Teledyne-Continental had a variable-piston research VCR roughly 20 years ago. And there are variations on another one or two themes. The Lotus project is just a single-cylinder research engine for now. I think what's caught so much attention is the combination of the 2-stroke basic cycle, and a fine job of hyping the government and other connections that are involved. It's a slick idea. We'll see if this one gets anywhere. -- Ed Huntress A couple years back, someone had a working prototype with an electric jackscrew that altered the crank relationship to the top of the cylinder, another used hydraulic pressure to effect the same result One of my customers is working with engineers at WVU on a low-compression diesel-fueled engine. It can use modern fuel-injection goodies, or possibly even a carburetor. The concept is pretty sweet. It is very practical, very simple, no unusual parts or machining involved. No high pressure injection pump with close tolerances. Our military is searching for practical small engines that run on diesel, and that's what is driving this project. Think diesel-fueled powerplant for tiny little drone aircraft. How small? There's already the diesel-power military bike based on the kawasaki KLR650 (all new engine), its about 650-700ccs I think. Dave small like 25-100cc The general rule is that a true diesel, running on conventional diesel fuel, requires a minimum cylinder volume of something like 250 cc. That's because there's too much quenching at smaller volumes, in which the surface area/volume ratio is inversely related to volume. However, there is an incredible amount of research being done right now on compression ignition, and dual ignition with spark plugs and glow plugs. Go to the SAE site and search on "compression ignition." You'll get over 7,000 hits on SAE papers, the more recent of which are mostly about HCCI (homogeneous charge, compression ignition) and there are some on SACI (spark-assisted, stratified-charge). Everything you can think of is in play, including mixed fuels, mixed ignition, and more. There are free abstracts on most of the papers: www.sae.org You may be aware that model "diesels," which generally don't have injection and thus are not considered true diesels, use ether as a fuel and can be very small in displacement volume. Ether has a cetane rating of something like 82, so it's very easy to ignite with compression. -- Ed Huntress Thanks for the info, Ed. You'll note my carefully chosen description "diesel-fueled." The end user doesn't really care how it is achieved, as long as the fuel is the same as the rest of their fleet uses. This is why kawasaki developed their diesel bike, to help the military machines achieve their goals of being "one-fuel" armies Find the market, fill the market. Sweet. =) That's always a good idea. d8-) Well, dual-fuel spark-ignition engines, which warm up running gasoline and then switch to kerosene (and probably diesel fuel, although I'm not certain about that) have been around for most of a century. They were popular for use in pumping water and other utility jobs on farms, and for some low-specific-output applications in industry. It probably would take something fancier to get a decent power/weight ratio for small aircraft, but the concept is well-proven. The duel fuel spark ignition engines are alive and well in some 3rd world countries, or were until very recently. I have seen kerosine/gasoline fuel outboards used in Indonesia fairly recently. Given the availability of small air cooled diesel engines today I doubt that the duel fuel engines are really practical as they do not produce the power that either the pure gasoline or pure diesel versions do. Bruce-in-Bangkok (correct Address is bpaige125atgmaildotcom) |
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OT- 2 stroke-/ variable c/r, direct injection engine
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OT- 2 stroke-/ variable c/r, direct injection engine
On Sat, 16 Aug 2008 09:14:16 +0700, Bruce in Bangkok
wrote: That's always a good idea. d8-) Well, dual-fuel spark-ignition engines, which warm up running gasoline and then switch to kerosene (and probably diesel fuel, although I'm not certain about that) have been around for most of a century. They were popular for use in pumping water and other utility jobs on farms, and for some low-specific-output applications in industry. It probably would take something fancier to get a decent power/weight ratio for small aircraft, but the concept is well-proven. The duel fuel spark ignition engines are alive and well in some 3rd world countries, or were until very recently. I have seen kerosine/gasoline fuel outboards used in Indonesia fairly recently. Given the availability of small air cooled diesel engines today I doubt that the duel fuel engines are really practical as they do not produce the power that either the pure gasoline or pure diesel versions do. Enfield (India) still sells their diesel powered motorcycles. http://www.gizmag.com/go/4272/ http://www.realclassic.co.uk/diesel05112800.html The hottest places in hell are reserved for those who in times of great moral crisis maintain their neutrality", John F. Kennedy. |
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