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joat mon posted:23,342 lb-ft So being generous, that means we only need 267 rotors.
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Apr 28, 2010 20:16
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rscott posted:how big would an apex seal be on a wankel engine making 4000 HP? Not big enough to keep from blowing out when you look at it funny.
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Apr 28, 2010 20:46
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Nam Taf posted:Here's pics from an EMD 710 I was doing some work on. The Wikipedia article says that the EMD 710 is a two-stroke, but I think I see valves in the first picture! Are they just large mechanical injectors?
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Apr 28, 2010 21:45
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xp67 posted:The Wikipedia article says that the EMD 710 is a two-stroke, but I think I see valves in the first picture! Are they just large mechanical injectors? Arent these Miller cycle 2 strokes with exhaust valves?
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Apr 28, 2010 21:54
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scapulataf posted:I'm certainly mot calling bullshit, or disputing this in any way, but that piston seems to be quite small given the length of the crankshafts in locomotive engines. The piston is actually broken about half or two thirds of the way down the skirt as far as I can tell, the skirt being the shiny (aluminum?) part. I guess the crown is steel or iron or whatever. As mentioned before this is on a GE AC4400. Seat Safety Switch posted:Holy poo poo, what are the chances of that happening? It looks like it brought some hot engine oil along with it, judging from how it splashed against the drywall as it ruptured through the house. In my experience, there isn't a whole lot in the way of preventative maintenance other than oil/filter changes done on these things; it's pretty much just run 'em until they blow up and hope the crank/block doesn't get damaged. There are better (more expensive) ways to do things for sure, but this is how it is. It should be noted that the kind of failure I posted is pretty extreme, usually things just asplode inside the block and it ends there, or as shown in the video posted earlier. Also I hosed up a bit earlier, it's the piston and articulating rod together that weigh 94lb, the piston itself is probably like 50 or 60. Here is a failure where the crank DID get damaged:  (Looking in through the inspection porthole. I can just about fit my head and maybe one arm through there) Somehow the main bearing caps/nuts/studs broke and two or three throws worth of crank fell into the oil pan. You can see the main journal at the lower left and the Upper Main bearings where I have halfass mspainted them. The master rod in the middle there is pretty beefy (piston/master rod assy runs just over 200lb) but when one of the intercoolers fails and water gets into a cylinder, they'll fold up like a pretzel. TheShedDweller posted:Arent these Miller cycle 2 strokes with exhaust valves? Miller cycle I'm not sure about, but they are definitely two strokes with exhaust valves. In the picture of the heads that was posted, the two outside rockers are for the valves and the middle one is for the injector.
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Apr 29, 2010 00:04
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Coworkers car. Went in for a brake job. Drove to work. Started to drive home when tire started dragging. Guess what, they forgot to install pads. He went to go bitch them out 2 days later (after we swapped out the rear calipers), and they had completely closed up shop and disappeared.
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Apr 29, 2010 02:07
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SGNL06 posted:
Yes, they just scavenge with the forced induction. Double the power strokes is double the power.
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Apr 29, 2010 03:51
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iscariot posted:Coworkers car.  How could you drive even 10 feet and not notice the awful grinding, lack of braking power, and metal on metal screeching coming from the back of the car? Or, for that matter, not notice that you didn't install any loving pads? Are people really this oblivious? 
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Apr 29, 2010 03:54
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Once I had a break job done where they didn't screw in the bolts holding in the pads, then the pads promptly swung down and ground against the wheels. ...That was fun.
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Apr 29, 2010 04:06
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I can't find a picture of it anywhere, but as I recall the largest Wankel engine ever built was an Ingersoll-Rand model that was designed to run the pumps along natural gas pipelines, using the gas itself as fuel. I know it was a two-rotor developing greater than 1000 hp and it displaced something like 80 litres, but I don't know what the physical dimensions would have been.
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Apr 29, 2010 09:23
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Gas turbine - electric motor drivetrains has to be a pretty good low maintenance alternative for trains and gas pipe pumps. I suppose its the norm for the latter, but does anyone know if it's common on the former?
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Apr 29, 2010 13:57
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Ola posted:Gas turbine - electric motor drivetrains has to be a pretty good low maintenance alternative for trains and gas pipe pumps. I suppose its the norm for the latter, but does anyone know if it's common on the former? It's been done. http://en.wikipedia.org/wiki/Gas_turbine-electric_locomotive
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Apr 29, 2010 14:45
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TheShedDweller posted:Arent these Miller cycle 2 strokes with exhaust valves? No Sponge! posted:Yes, they just scavenge with the forced induction. Double the power strokes is double the power. What? No. Miller cycle engines are four-stroke. A Miller cycle uses a two-part compression stroke. The initial quarter of the stroke the intake valve is left open, allowing the supercharger (Miller cycle engines require positive displacement superchargers) to compress the intake charge. The the intake valve then closes after about a quarter of the compression stroke has completed, allowing for traditional mechanical piston compression to happen.
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Apr 29, 2010 14:51
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trouser chili posted:No I guess what I meant to say is, like a Miller cycle engine it uses constant pressure forced induction. Only on a 2 stroke diesel rather than a Otto cycle. But unlike most 2 stroke motors, they have exhaust valves at the top of the combustion chamber instead of ports to help increase compression. A guy I knew who worked as a diesel mechanic explained it to me like this... At the bottom of the compression stroke the forced induction system pushes air through the cylinder with the exhaust valves open, forcing out any leftover exhaust from the previous cycle. The compression stroke takes place. The exhaust valves close as the upward moving piston reaches the intake port. The piston compresses the intake charge. At or around TDC the injector sprays fuel into the combustion chamber, Bang! As the downward moving piston passes the intake port on the combustion stroke the exhaust valves open. Then the pressure from the turbo/supercharger pushes the exhaust gasses out of the cylinder. At least that is how it was explained to me, let me know if I got any of that wrong.
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Apr 29, 2010 17:56
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SGNL06 posted:Miller cycle I'm not sure about, but they are definitely two strokes with exhaust valves. In the picture of the heads that was posted, the two outside rockers are for the valves and the middle one is for the injector. Do those wussy little medium-speed diesels do underpiston scavenging, like a real manly man 76M?
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Apr 29, 2010 18:04
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TheShedDweller posted:
Nah you got it bout right
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Apr 30, 2010 00:10
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OWLS! posted:Once I had a break job done where they didn't screw in the bolts holding in the pads, then the pads promptly swung down and ground against the wheels. I did something similar last weekend. One pad worked its way out, but got wedged against something else so it didn't completely fall out...but it did let the pistons pop out just enough that all my brake fluid burst out onto the interstate off-ramp about 200 miles into a road trip, after being my normal daily driver for two loving days. If there's a good time to have your brakes fail, this was it. I had like 1/3 of a mile to downshift then bring it to a stop with the parking brake, had just gotten through a congested construction zone...seriously, I have no idea what I did in a past life to earn that kind of karma. There were so many times I could've been completely hosed.
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Apr 30, 2010 00:53
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hey, my 01 Mazda Millenia S has a Miller Cycle. I think it was one of the only production cars to have one, wasn't it?
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Apr 30, 2010 01:24
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Robawesome posted:hey, my 01 Mazda Millenia S has a Miller Cycle. I think it was one of the only production cars to have one, wasn't it? The only. E: Although the Atkinson cycle in the Prius is similar, Miller without the forced induction.
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Apr 30, 2010 01:26
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Ola posted:Gas turbine - electric motor drivetrains has to be a pretty good low maintenance alternative for trains and gas pipe pumps. I suppose its the norm for the latter, but does anyone know if it's common on the former? They've been done, as mentioned, but they produce their best power a) through massive RPMs and b) when the inlet temperature is cold. As such, the Switzerlands, the Canadas and the Russias get decent use out of them as passenger trains, because they can go fast and have decent grunt in the cold. We did a 2 page 'formal investigation' into them about a decade ago, off memory, before writing them off. I assume this was done because some non-technical role heard about them and insisted we investigate them. Firstly, the bulk of our rail network deals with coal haulage, which is all about torque and low speed power. Secondly, it is doing this through 40-50 degree celsius areas, so the power of a gas turbine would be shot to poo poo. Anyhow, for content (and I've no idea if this has been posted yet, sorry guys!), whilst not mechanical destruction specifically, this has got to be a surefire way of ensuring it'll be impressive when it inevitably does: 
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Apr 30, 2010 13:18
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Nam Taf posted:Anyhow, for content (and I've no idea if this has been posted yet, sorry guys!), whilst not mechanical destruction specifically, this has got to be a surefire way of ensuring it'll be impressive when it inevitably does: Haha, internal speed holes!
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Apr 30, 2010 15:10
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EVERYWHERE 
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meatpimp posted:Haha, internal speed holes! I'm imagining the guy doing it, thinking he's smart; really, really smart; doing the math, balancing the crankshaft for the reduced mass of the connecting rod, and completely and totally overlooking the fact that that drat rod was already made as light as drat well possible without failing under strain... 
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Apr 30, 2010 15:12
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Sponge! posted:I'm imagining the guy doing it, thinking he's smart; really, really smart; doing the math, balancing the crankshaft for the reduced mass of the connecting rod, and completely and totally overlooking the fact that that drat rod was already made as light as drat well possible without failing under strain... And after all that bs he can't even get the holes to go in a straight line. I really want to know what happened
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Apr 30, 2010 15:58
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Nam Taf posted:They've been done, as mentioned, but they produce their best power a) through massive RPMs There's a reason the original post was about turbine-electric power, and not geared direct drive turbine.
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Apr 30, 2010 21:11
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sandoz posted:There's a reason the original post was about turbine-electric power, and not geared direct drive turbine. Even still, try sending a consist of turbine-elec units through the average north american loading gauge tunnel and watch as everything behind the first one flames out and dies...
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May 1, 2010 04:36
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here's what happens when you put a bunch of lovely e-bay parts on your subaru: and here's what happens when you drive a bone stock 08 sti:  and here's what happens when the machine shop doesn't properly torque rod bolts: 
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May 1, 2010 06:18
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jamal posted:
I've heard of shops doing this so many times and it blows my mind every time. I mean, it's such an important and simple step.
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May 1, 2010 17:10
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my1999gsr posted:I've heard of shops doing this so many times and it blows my mind every time. I mean, it's such an important and simple step. but you have to torque them twiiiicccceeeee*  At least with hondas and toyotas/yamahas.
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May 1, 2010 17:20
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ratbert90 posted:but you have to torque them twiiiicccceeeee* And with Plymouths, too. During the rebuild of my 383 in 1987, I checked the main bolt and connecting rod nut torques at least three times before buttoning up the pan. Four months later, it threw the rod on #3 after the bearing cap nut worked loose. Apparently, I was supposed to pull the pan & re-torque them again after the first 1000 miles. Which is odd, since they don't do that at the factory. Then again, it could've been my cheap-rear end Pep Boys torque wrench.
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May 1, 2010 19:47
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PainterofCrap posted:And with Plymouths, too. During the rebuild of my 383 in 1987, I checked the main bolt and connecting rod nut torques at least three times before buttoning up the pan. Four months later, it threw the rod on #3 after the bearing cap nut worked loose. Apparently, I was supposed to pull the pan & re-torque them again after the first 1000 miles. Which is odd, since they don't do that at the factory. I would have used some loctite, but that's just me.
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May 1, 2010 19:50
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One of your locomotive-heads should make a train thread. I would but I have no content  Trains are awesome and are the epitome of insanity. Motherfucking rolling bricks hauling THOUSANDS OF TONS AT 60 MILES PER HOUR 
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May 2, 2010 04:05
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ijustam posted:One of your locomotive-heads should make a train thread. I would but I have no content I'd certainly read it, but I don't know of any words for trains that start with "A." so far we've got Automotive, Aeronautic, Aquatic...?
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May 2, 2010 04:48
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Boat posted:I'd certainly read it, but I don't know of any words for trains that start with "A." "A train thread" "Trainsanity" "Locomotive insanity" etc etc ninja edit: Only one of those began with A 
zifflol fucked around with this message at 05:46 on May 2, 2010 |
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May 2, 2010 05:43
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Strtching the theme a bit here, but here's a vid where the horrible failure is the driving skills of the person behind the wheel. https://www.youtube.com/watch?v=tMDB8l0lzos I'm not usually a 'yell advice at the screen' type of person, but this woman nearly had me doing it.
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May 2, 2010 06:56
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Gorilla Salad posted:Strtching the theme a bit here, but here's a vid where the horrible failure is the driving skills of the person behind the wheel. While that isn't mechanical, that woman clearly had an electrical fault in her head. Here's what a Lada driver looks like: http://www.youtube.com/watch?v=MiySKuVs2fI
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May 2, 2010 07:49
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Wrong thread, that just proves that Ladas are indestructible. Some friends of mine drove a Niva into a ditch and it was completely undamaged.
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May 2, 2010 08:06
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It's not proof, it's an anecdote. Here's to the underdog. Here's something that is undoubtably suited for this thread: http://www.youtube.com/watch?v=SF3r5ImsHXA&feature=related I don't think it's been posted here, but perhaps it's in the million or so pages of that YouTube thread I've not yet read.
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May 2, 2010 08:24
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buzzomatic posted:It's not proof, it's an anecdote. Here's to the underdog. the coating on the titanium rods wears off, they gall on each other, and boom, that happens.
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May 2, 2010 10:49
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May 2, 2010 14:47
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VanFullOfMidgets posted:What am I missing here?
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May 2, 2010 15:36
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