Well there is that, and some other things.

Post #318,790 by Another Scott 12/18/09 12:41:56 PM Reply	Well there is that, and some other things. Lots of good comments in that thread. (Apparently the Stanley Steamers used a pilot light to keep the water from freezing.) I'd like to see a lot more than a drawing before offering an opinion on whether this makes sense for transportation. (E.g. does it need a honking-big heat exchanger?; why so many pistons?; why not use a rotary engine rather than pistons if you're going for maximum efficiency?; etc.) Cheers, Scott.
Post #318,803 by boxley 12/18/09 2:29:26 PM Reply	uh, that is a rotary engine I know you mean something else, turbine perhaps?
Post #318,807 by Another Scott 12/18/09 3:14:31 PM Reply	Yeah, if you want to get all technical about it... ;-) Something that doesn't require vertical motion to be translated into rotary motion. Cheers, Scott.
Post #318,865 by static 12/20/09 1:31:24 AM Reply	Turbines are really different to pistons. A small, portable powerplant driven by reciprocating motion is A Solved Problem. Weight vs power, torque curves, power bands, etc etc. This has been done millions of different ways over the years. Turbines are a wholly different animal. They like size: the most efficient ones are in power stations and in jet aircraft. Attempts have been made to create car-sized versions with petrol, but they are very inefficient for their size and weight. Steam would have the same problems. Heck, they stopped at pistons for locomotives. Wade. Q:Is it proper to eat cheeseburgers with your fingers? A:No, the fingers should be eaten separately.
Post #318,868 by Andrew Grygus 12/20/09 2:25:32 AM 12/20/09 10:55:54 AM Reply	The big advantage of pistons is . . . . . torque - and it's torque that makes the wheels go round. Look at all those big steam locomotives with just two small pistons to drive them - and all the loaded rail cars they were towing. Of course pistons in an automobile are 4 stroke (2 up 2 down per power cycle) while locomotive pistons are 1 stroke - power on both the forward and back strokes. Can you imagine the gear train and the number of gear ratios you'd need to do that sort of thing with a turbine? Of course they wouldn't do it that way. If a locomotive had a turbine engine it would work like a diesel locomotive. The diesel engine drives an electric generator and the wheels are driven by electric motors. This allows the power plant to achieve the efficiency of a stationary engine, running near it's ideal power point regardless of the speed of the train. Since electric generators and motors run at efficiencies in the mid to high 90% range, this is very practical. Edited by Andrew Grygus Dec. 20, 2009, 10:55:54 AM EST Expand All History
Post #318,880 by static 12/20/09 7:16:41 AM Reply	Diesel-electric locos. Good example. Q:Is it proper to eat cheeseburgers with your fingers? A:No, the fingers should be eaten separately.
Post #318,891 by folkert 12/20/09 12:41:07 PM Reply	Re: The big advantage of pistons is . . . Only GM EMD Diesel Electric Locomotives are 2 stroke diesels. They have "poor" electrical rectifiers that can only pump out max current for 120 seconds continuously and then only with over ride after 90 seconds, they will automatically throttle back after the 90/120 seconds to keep the rectifiers (660v DC at 3000A) from being burnt up. GE made Locomotives are 4 stroke. They sound really whacky and sound like they aren't running properly, as compared to the GM EMD Locomotives. The one thing about the GE Locomotives is that they have awesome rectifiers in them. They can run at 660v at 3000A all day. These are the ones the railroads use in the coal mining hills as they can just pull and pull and pull with out burning up the rectifiers. All this considering that all the 6/8/12/16 Cylinder diesel motors in these locomotive "low" idle at 236 RPMs and the maximum emergency speed it 1056 RPMs. Many Road Engineers I've talked to (before 9/11 when all the "infrastructure" point became federally enforced and "go to jail" offenses on the first time), they all want a GM EMD locomotives due to the way the engine responds and runs... on short delivery/day runs and switching tasks. On longer runs they all want the GE Locomotives because they way the whole package works... they still hate the engine, it shakes and bucks more. One RE told me that he'd like to have a GM EMD 2-stroke Diesel driving the GE Electrics... that'd be perfect. But it'll never happen.
Post #318,886 by drook 12/20/09 12:08:02 PM Reply	What about the Indy turbine? http://rcooperimages...l/stp_40_car.html -- Drew
Post #318,892 by Andrew Grygus 12/20/09 1:02:55 PM Reply	Re: What about the Indy turbine? Rather bulky and impractical. If I remember correctly from the time, it took some practice to drive it because of the time it takes for a turbine to wind up after you depress the accelerator. This is why carrier pilots start winding up the turbines just before the tail hook catches, so if it doesn't catch they'll have enough power to fly by time they run off the end of the deck. Yes, a turbine can work in a non-real-world situation like oval course racing - but attempts to put turbines on the road have failed to be practical.
Post #318,904 by static 12/20/09 4:56:19 PM Reply	What Andrew said. It doesn't spin up at anything like the responsive speed needed for a roadcar. And it was big and heavy. It needs to be a lot smaller, and respond a lot quicker to match a piston engine. Great example though. If someone with deep deep pockets back then had been truly determined to make road cars - eventually - then we might now have Lamborghinis or similar with turbine engines. And the gearbox would probably have about 30 gears... Wade. Q:Is it proper to eat cheeseburgers with your fingers? A:No, the fingers should be eaten separately.
Post #318,889 by Mycroft_Holmes_Iv 12/20/09 12:18:23 PM Reply	I seem to recall a small aircraft turbine engine that's available. (Weight is less than a Rotax 912UL and roughly same hp) Researching.
Post #318,893 by Andrew Grygus 12/20/09 1:10:57 PM Reply	A little more than a year ago . . . . . I saw Jay Leno riding his turbine powered motorcycle down Magnolia Blvd. in Burbank. The engine came from a crashed small helicopter. It makes a very odd sound and it's certainly a curiosity, but I doubt it's very practical or economical - but he can afford anything he wants.
Post #318,983 by Ashton 12/21/09 11:02:43 PM Reply	Have a pic of Leno astride a Vincent Autographed yet.. off eBay, for a song. As with a calendar pic which seemed ~~ to be the S/N of one of my Shadows! (but enjancement found 2 questionable digits) -- was curious if I could recognize any details of his pukka specimen as perhaps having passed through one of my better-than-new refinements -??- (like substituting Titanium for aluminium, at a place in the f. brake system.) Nahhh. Oh well. I expect that he pays whatever it takes to get 100% OEM bits, down to the teensiest Whitworth fasteners -- Cad-plated as original. But where's the fun in payin someone else to indulge one's own micro-accuracy fetish?
Post #318,896 by Another Scott 12/20/09 1:45:25 PM Reply	There's the HondaJet http://hondajet.hond...rbofanengine.aspx - < 400#, 1880 lbf thrust at takeoff, 22.1" OD, 44" long, < 0.7 lb/hr/lbf fuel consumption. Dunno anything about the Rotax 912UL ... They seem to be in different classes. Someone who knows a lot more than me would have to do the conversions to compare specific fuel consumption, etc. There are tiny jet engines for models. http://www.artesjet.com/prod04.htm ! Presumably there's an optimum size for best efficiency. Cheers, Scott.
Post #319,021 by Mycroft_Holmes_Iv 12/23/09 12:48:02 AM Reply	Well, the company I was thinking of... (I think) was Innodyn (http://www.innodyn.com/). However, their web site doesn't seem to be up anymore. :-( It's also possible I was thinking of N2 Turbines (http://www.n2turbines.com/) Their specs are good (http://www.n2turbine...m/performance.htm). They definitely burn more fuel (14 gal / hr) than say a piston (Rotax http://en.wikipedia.org/wiki/Rotax_912) (5 gal / hr) but weigh less and need less maintenance. These are all TurboProp thingies. Jets take it to a whole different level. :-)
Post #319,057 by Another Scott 12/23/09 6:59:58 PM Reply	Neat. Thanks.
Post #318,810 by Ashton 12/18/09 3:37:40 PM Reply	NYT crossword entry -- on nitpickery: (in a puzzle entitled, Double Break Point, Ed. by Will Shortz == the Maestro) Assaulttrifles :-þ
Post #318,812 by Andrew Grygus 12/18/09 4:17:37 PM Reply	Can you assure them that . . . . . you have solved the seal problems? Of course there's turbines, but then you're talking major gear trains - and you completely lose the torque and acceleration advantages of steam.

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