Re: [MBZ] Why no two stroke diesels? Damn good reasons.
Two stroke diesels need superchargers to get air in the cylinders, as Hendrik says. They tend to have a narrow power band, as Tom Hargrave said. Herewith an illustration of why no two stroke diesels in cars, taken from real life: When I was in the army in a past life, my unit had Letourneau Turnadozers, which were an abominable tractor with four huge fat rubber tired wheels on a really close coupled short wheelbase. They steered with steering clutches and brakes, all electrically operated. Each one ws issued with a large VOM for troubleshooting. They needed the VOM's. The power unit was a GMC 6-71 diesel, supercharged of course, at the engine drove a generator. The engine ran at one governed speed which must have been near as fast as the thing would turn. You could hear one screaming for it seemed like miles. The supercharger made much of the scream I forget how we started them. Seems like we popped ether capsules in a fixture into the intake and cranked, with a starter of course.. I promise you no sane person would want anything even vaguely resembling the Tournadozer power plant in a car. Or a truck. And they shouldn't have been in The TD's. I understand the Tournapull, a two wheel pure pulling unit, was really pretty good. The TD's were awful. Nothing but trouble. It didn't help that they were old at the time. -- Hendrik <[EMAIL PROTECTED]> wrote Subject: Re: [MBZ] Why no 2 stroke diesels Two stroke in general never really took off in the car segment. The disadvantage of 2 stroke Diesels is that they need a supercharger to make em work. Why design a complicated 2 stroke engine when it is far easier to build a four stroke. Petrol two strokes don't need a supercharger and are relatively light, which makes them ideal for applications where horsepower is needed but a heavy engine isn't. Such as chainsaws, motorcycles (particularly off road ones) and a variety of other special things. Perhaps with the introduction of CDI technology we may see a two stroke Diesel in cars, or even small Diesel motors in general. Peter Merle wrote: > Why does the 2 stoke diesel not exist in passenger cars ? Are the > emmisions too high? > Peter > > ___ ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Why no two stroke diesels
The plane in which I flew at Cape Cod did 120 db at takeoff power. Some young chick from OSHA showed up one afternoon and wanted to take measurements. I put her in "my" seat (radio) and cranked up the engines. We sort of BROKE her meter (needle wrapped around the right side stop). I did ask her if she really wanted to do this, because the engines (dual R-1820s) were pretty loud. She insisted. I had warned her ... she didn't listen ... she left really pissed off at me. Ooops, guess I broke her stuff. D. On 9/20/07, Jim Cathey <[EMAIL PROTECTED]> wrote: > > > No that is not quite right, apparently the 6/71 numbers mean that it > > makes 6 horsepower and has 71 oil leaks :-) > > Completely wrong. It's a decibel rating, the / was meant > to try to hide the decimal point! > > -- Jim > > > ___ > http://www.okiebenz.com > For new parts see official list sponsor: http://www.buymbparts.com/ > For used parts email [EMAIL PROTECTED] > > To Unsubscribe or change delivery options go to: > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > -- LT Don http://don.homelinux.net/~don/ Proudly marching to the beat of a different kettle of fish. Make a small loan, Make a big difference - Kiva.org ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Why no two stroke diesels
> No that is not quite right, apparently the 6/71 numbers mean that it > makes 6 horsepower and has 71 oil leaks :-) Completely wrong. It's a decibel rating, the / was meant to try to hide the decimal point! -- Jim ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Why no two stroke diesels
No that is not quite right, apparently the 6/71 numbers mean that it makes 6 horsepower and has 71 oil leaks :-) Dan Weeks wrote: > There were LOTS of 2-stroke diesels made, the most famous being the > detroits. They were THE heavy diesel engine for marine and heavy > vehicle use for decades in this country. THe engine was modular, > availalbe from 2 cyl to 12 cyl (maybe 16, I donno) versions. The most > popular was the 6/71--6 cyl, 71 cubes per cyl. Made about 210 hp in > working trim and were universally known as "screaming Jimmies" for > their high-frequency racket. Someone once described the engine as > making a sound akin to "an all-night fight between dogs and geese." > They were the GM city bus engine for decades, and were also used in > Greyhounds and many semis until the 70s and later. 8/ and even 12/71s > were also used in semis—the 12/71 was nicknamed the "buzzin' dozen." > They were relatively cheap, extremely simple, and produced pretty > good power for their weight, but weren't as efficient or easy to > turbocharge as 4-stroke engines, and had relatively narrow power > bands and very little low-speed torque, making for lots of shifting. > They were better suited to marine use, and I believe they were > originally developed to power landing craft during WWII. My brother > has a '73 International semitractor with a 6/71, and it's very hard > to get used to after driving, say, a Cat or Cummins semi--you have to > rev it until you're sure it's going to explode, and THEN the power > starts coming on. Given my limited experience with that, I much > prefer 4-stroke diesels for torque and quiet. > > Dan > > > > ___ > http://www.okiebenz.com > For new parts see official list sponsor: http://www.buymbparts.com/ > For used parts email [EMAIL PROTECTED] > > To Unsubscribe or change delivery options go to: > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
Re: [MBZ] Why no two stroke diesels
There were LOTS of 2-stroke diesels made, the most famous being the detroits. They were THE heavy diesel engine for marine and heavy vehicle use for decades in this country. THe engine was modular, availalbe from 2 cyl to 12 cyl (maybe 16, I donno) versions. The most popular was the 6/71--6 cyl, 71 cubes per cyl. Made about 210 hp in working trim and were universally known as "screaming Jimmies" for their high-frequency racket. Someone once described the engine as making a sound akin to "an all-night fight between dogs and geese." They were the GM city bus engine for decades, and were also used in Greyhounds and many semis until the 70s and later. 8/ and even 12/71s were also used in semis—the 12/71 was nicknamed the "buzzin' dozen." They were relatively cheap, extremely simple, and produced pretty good power for their weight, but weren't as efficient or easy to turbocharge as 4-stroke engines, and had relatively narrow power bands and very little low-speed torque, making for lots of shifting. They were better suited to marine use, and I believe they were originally developed to power landing craft during WWII. My brother has a '73 International semitractor with a 6/71, and it's very hard to get used to after driving, say, a Cat or Cummins semi--you have to rev it until you're sure it's going to explode, and THEN the power starts coming on. Given my limited experience with that, I much prefer 4-stroke diesels for torque and quiet. Dan ___ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
