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Opposed piston-opposed cylinder engine

Posted by SSsssteamer 
Opposed piston-opposed cylinder engine
February 10, 2011 01:53PM
Opposed piston- opposed cylinder and with in perfect balance. Lower heat rejection, and etc. means a 40 percent better fuel mileage than a conventional engine. As a diesel engine, the compact two cylinder engine produces 300 h.p Piston speed is half of what a conventional engine would have for the same displacement. This engine presently is being installed into military test beds. Can be used for diesel, gas, or as a steam engine. Due to its design, it give four power strokes to every single revolution, just llike a Stanley steam engine. Wrist pin and cylinder lubrication was one challenge that it had and it has been addressed. Check it out at: [www.engineeringtv.com]
Re: Opposed piston-opposed cylinder engine
February 10, 2011 04:18PM
Old idea and old concept. They made three crank diesel engines as well as double wobble plate engines with apposed pistons.
I’m not on my computer or I would post some photos.
A member of SACA-NE has a beauty, double wobble plate. George-N can tell us all about it.
Rolly
ben
Re: Opposed piston-opposed cylinder engine
February 10, 2011 04:38PM
I think Fairbanks and GM made diesel flat diesels in the 1930s,,,similar to this,,,,Early engine like this,,French? Gorbrun-Brille set early speed record around 1903 A 1907 was at Hershey a few years ago,,large car Ben
Re: Opposed piston-opposed cylinder engine
February 10, 2011 06:41PM
So what's to discuss?
Any engineering student from the 1950s had, or should have had like we did, a professor of engine design and dynamics who said that from a balance and thermodynamic standpoint, this layout WAS and IS the best way to make an IC engine with the highest output of any engine of similar displacement. As I recall him saying: "Now, if you want really frantic output from any engine, this is the only way to go."

The balance, as the two crankshafts are exactly phased 180* apart, is perfect, since they rotate in opposite direction. Newton was right.
The exhaust port area is huge. The heat losses are the least you can get. If the synchronizing cross shaft is used and not one of the crankshafts, the engine can lay flat under the rear of the vehicle. Now it is easy to include on that shaft a two speed-neutral gear set on the drive gear, then go up to the driven gear on the differential. Nothing says that the cross synchronizing shaft has to turn at the same speed as the crankshafts either.
First done by an Italian engineer in about 1876. Junkers made them in Diesel format for aircraft. FIAT made a wild supercharged 1-1/2 liter two stroke for Grand Prix racing in about 1926, The TIPO 451. Fairbanks- Morse made thousands of them for submarine and locomotive service. Others did too under license.
The Napier Deltic Diesel while having great power, was the most complicated, expensive and hard to service engine ever known. The gear case was unbelievable. Typical British fussy overkill.
LA Fire Dept. had one in a pumper trailer, I saw it being tested at the Long Beach harbor. The guys said it was great as long as it ran; but service was a total nightmare. Replaced by a big V-12 Cat Diesel.

Get the book "Opposed Piston Engines" from Amazon or the SAE bookstore and get educated. Only book devoted to this engine format and worth every penny.

That engine shown on the video was tested by Mercury Marine and they said it was the dirtiest two stroke engine they ever tested. Two vulture capitalists, one right here in Palo Alto and Bill Gates invested $25M in it. And Harry cannot get one fifth of this for a superior engine?? Watch this one fade away as all the rest like it have done.
Two stroke IC engines even with direct fuel injection are simply very dirty.
Compared to the two crankshaft design, this one is just silly, the inertia loads of the reciprocating masses are nasty to contemplate.

Jim



Edited 3 time(s). Last edit at 02/11/2011 10:17AM by Jim Crank.
Re: Opposed piston-opposed cylinder engine
February 10, 2011 08:09PM
Just a few of the opposed piston engines


[histomobile.com]

[www.fairbanksmorse.com]

[www.ssplprints.com]

[en.wikipedia.org]



Edited 1 time(s). Last edit at 02/10/2011 08:26PM by Rolly.
Re: Opposed piston-opposed cylinder engine
February 10, 2011 10:03PM
I just remembered
John Erickson Monitor engine was a opposed piston steam engine.

[www.youtube.com]
Re: Opposed piston-opposed cylinder engine
February 11, 2011 03:51PM
I have been looking at an opposed piston engines design. But for a far different reasion.

For simplicity of the math a scotch yoke crank is easiest to calculate. The piston position simply follows a sine wav function.

Piston position as a percentage of stroke is given by the simple formula position = (1 - cos(a))/2 At 0 degrees (TDC) the pistion position is (1 - 1)/2 = 0 and at 180 degrees the piston position is (1 - (-1))/2 = 1 BDC. now seting up two of these as opposed pistons we can simply figure the piston position as the sum of the two devided by 2. But adding a phase shift between the two opposing cranks we get piston position as:
(1 - cos(a+s)) + (1 - cos(a-s)))/4

cos(u+v)=cos(u)cos(v)-sin(u)sin(v) and cos(u-v)=cos(u)cos(v)+sin(u)sin(v)

The position formula becomes: (2-(cos(a)cos(s)-sin(a)sin(s)+cos(a)cos(s)+sin(a)sin(s)))/4 = (1-cos(s)cos(a))/2

The cos(a) function generates a sin wave about 0. between 1 and -1. The cos(s) where s is the phase angle shift of the cranks in opsite direction produces an effective atunauation of the stroke about it"s center point The cos(a) is betwwen 1 and -1 multiplied by cos(s) which can be varied from 1 down to 0 changes the efficitave stroke of the engine.


This engine has variable displacement while also varing the clearance. The stroke reduction is cos(s). s=0 the stroke is 100% at s=90 the stroke is 0%. The engine would have some clearance at full stroke. say its 3% at cos(s=0)=1. with cutoff at 34.33 we would have a 3:1 expansion ratio. With s=57.99 degrees cos(57.99)=0.53 We have a 3 to 1 ratio between BDC volume and clearance volume. 3:1 expansion ration at 0 cutoff.

With a 0 to 34% cutoff varing the steam amount and with a displacement reduction of 53% we have variable power with constant expansion ratio of 3:1. with 3 stage expansions it would get a constant 27:1 expansion ratio with varing power.

I doubt that cutoff can be varied down to 0, Maybe 3% cutoff can be achieved.That would make the steam volume varry from .3433% of the max displacement to 3% of .53 = 1.59% for a 22.44:1 cutoff steam volume variation. That would get around a 4.74:1 spead range.

The idea is to get close to a turbine performance with a piston engine. By having close to full expansion over a 5:1 speed range you get the max efficiency. Lowest heat content in the exhaust steam. Another idea is that at high RPM one can expand into the two phase region and not get water droplets. It takes around 15 to 30 miliseconds for steam to condense into water droplets. So it may be possable to exhaust the steam before water droplets form in the cylanders. Expanding into the subcooled vapor region is something to be explored in high RPM steam engines.

Andy
Re: Opposed piston-opposed cylinder engine
February 11, 2011 05:01PM
Interesting stuff Andy.
I had been thinking about the limitations of expansion in a uniflow engine which doesn't positively displace exhaust steam.

15ms is the half cycle time at 2000 RPM. Is the implication that above this speed, no droplets can ever form in the cylinder?

If this is the case and expansion is extended into the subcooled, presumably the steam is condensing to vapour. This phase change must necessarily create a massive drop in pressure. Surely this would be a bad thing during the power stroke, creating negative cylinder pressure and retarding the piston?

I am considering an opposed piston design, but the second piston is to function primarily as an inlet valve, using the smallest stroke possible. I have a broad scheme for a mechanism to control clearance and cutoff. It's a mix of a swashplate and Stephenson reversing gear at the moment, but I'm sure I can make it a lot less complex.

Pete.
Re: Opposed piston-opposed cylinder engine
February 11, 2011 07:00PM
One of the design issues I have ran into is valve open close time. Controling valve timing independent between stages and inlet exhaust is the major thing. I have found an electric-magnetic controled valve design that can be opened and closed in 4 miliseconds.Which just makes it possable to run 15MPH in this mode. The engine can run in lower expansion modes for overlaping inlets and more power. I am trying to get a 5 to 1 speed range of 15 to 75 MPH in the full expansion mode. At lower speeds the valve can be opened and closed iny were in the power stroke. The short open close hopefully can act as throttling. maybe skipping cylanders for power reduction. With the valve speed limitation the RPM is limited. Would like to run higher RPM for better power density. Getting equal power out of each stage is doable but the have to be sized just right. Using static calculations shows power leveles across it's power ramge can be kept within 5%.
Re: Opposed piston-opposed cylinder engine
February 12, 2011 01:11AM
Ah, the opposed-piston/opposed-cylinder engine. All those advantages, and only twice the complexity and cost of a conventional engine...

Peter
Re: Opposed piston-opposed cylinder engine
February 12, 2011 10:38AM
Hi Peter.

The oposed piston arangement is a bit hard to valve. I would prefer a single piston arangement with valves in the head. That said, the variable clearance displacement is what I am after. Another idea is to use two cranks but coupled to the piston rods with diferentiol slider. The cranks drive rack gears coupled to the piston rod by the pinion between them. Would have the same character as described in my last post. Yes it's complicated. But by using a full expansion over a wide power range it would still be the most efficient cycle. With throttling you are always wasting energy.

Andy
Re: Opposed piston-opposed cylinder engine
February 12, 2011 10:49AM
Hi Andy,

The idea of being able to change the engine characteristics by modifying crank phase relations looks interesting but seems like it may be problematic in actual operation. It is a dead certainty that making the cranks phase adjustable will cause the inherent balance of the engine to be replaced by an infinitely variable unbalance unless you do something like have 6 inline cylinders to provide inherent balance for each crank.

The crank phase change mechanism itself might have some issues. Cam phasers are pretty common, now, but cams aren't subjected to these kinds of forces, both inertial and power producing. In an opposed piston engine, the two cranks are going to be geared together, so changing the phase relationship of one crank is going to change the forces applied to the opposite crank. Since both cranks are connected to the output shaft, it will have to deal with the sum of the changing forces resulting from the phase shifts. The mechanism to create these phase shifts may have to be very robust and absolutely not have any significant play else small slips create sudden shock loading.

Crank phase changing will likely affect engine smoothness, beyond the balance changes, since the timing of the power pulses no longer coincide. The original GM V-6 from back in the 60s had decent inertial balance (certainly far superior to inline 4s of the day), but the distribution of the power pulses was less-than-optimal and resulted in a perceived rough running engine. Changing phases on the fly means the distribution of output forces during a revolution will also change, even spacing of the pulses will not be maintained, which will mean a good chance of the engine running rough.

For a hobbyist engine, anything goes, but from a manufacturing standpoint this would be hard to justify for smaller engines. To obtain the kind of reliability and endurance now expected, a crank has to be built to very demanding standards, and this doesn't come cheap---the crank competes with the block for being the most expensive single component in a vehicle. Doubling that expense is going to be hard to justify when customers are now often influenced by price points within a percent or so.

Regards,

Ken



Edited 1 time(s). Last edit at 02/12/2011 01:39PM by frustrated.
Re: Opposed piston-opposed cylinder engine
February 12, 2011 11:57AM
Andy,
Valve layout for an opposed piston engine with cutoff control over a wide range is extremely simple. No harder than any poppet valve configuration using cam actuation and including the Williams variable compression, zero clearance ideas.
Actually, there is no reason to complicate any steam engine design. We found long ago that if the right bore-stroke ratio was used, then torque could be what you wanted using the same BMEP, where you wanted it to be and controlled over a very wide range with long cutoff for starting and hill climbing (and showing off too), then short cutoff for good steam economy. Also the basic design could be tailored for high rpm and horsepower, or good wide range torque and power in a moderate speed and usable power band. It all depends on what you want this engine to do and how you want it do to the job.
Either three double acting or six single acting were about all you really needed for any car or truck. And, one has to choose either a very small engine that is worked very hard, or a more robust engine that will do the job and live for a long time. The term "Large" is relative. The DA engine has become just not suitable for a modern steam car.

Peter,
The unaflow opposed piston engine is no more expensive to make than any DA engine and about the same as a SA engine with six cylinders. Crankshafts are off the shelf items, as are connecting rods. Bearings design, if only water is used as the lubrication, is more complex; but again, good custom split double row water lubed ball or roller bearings are available that will take the torque loads and custom connecting rods are not all that expensive. I went through this with the eleven Doble crankcase kits.
Crankcases are symmetrical, the cylinder block can be designed to use the absolute minimum of cores and be a lot easier to cast than any DA cylinder with ports.
I think personally that it all depends on just what one wants to do with the Rankine cycle today. Talk about it for decades and never build anything that can be used. Try one's best to do the best possible job and bring this power source up to the level where it actually is competitive, or be content with just another parking lot dribbler. For years that was good enough, until this oil price manipulation and sourcing became a big national problem, along now with global warming becoming an issue that will not go away.
The SA opposed piston unaflow concept offers the best possible balance, the least thermodynamic losses and a very compact package overall actually.
No one ever said that designing and actually building a good modern steam powered car is either easy or cheap to do. If the resources, funds and skills needed are not there, then don't even start. Build a nice steamboat and enjoy vintage steam at its best, they are simply delicious.

Ken,
I know that old GM V-6 very well, my boss at Lockheed had one of those small Buicks with one in it. One glance at the 90* cylinder block angle and a three throw crankshaft was the biggest clue you ever needed. The thing would shake your back teeth out. Horrible layout; but very typical of GM doing things on the cheap in those days. Like that Chevy V-8 conversion to Diesel for Oldsmobile. Bad right from the start.
Right on the money. Changing crank angles on this opposed piston engine would create awful balance problems and why on earth would any engineer propose such a thing? Unless he actually didn't have any hands on experience with engines; but all theoretical. Not a bright idea at all, fixed 180* crankshaft phasing, opposite rotation and that is it.
So, does one build to a high engineering standard or down to some price? This is a one shot deal to make a car that will hopefully erase that horrible image Detroit has of any steam car, so the best is what one has to do, or just keep the whole thing as another expensive hobby.

Jim
Re: Opposed piston-opposed cylinder engine
February 13, 2011 01:46AM
Hi Jim,

I like a challenge as much as anybody, but making a valid case for this type of engine in a steam automobile looks pretty hopeless to me. Twice as many pistons and conrods as a conventional single-acting engine, and four times as many as a double-acting ["one-stroke"] engine -- to do the same job. Plus 2 expensive and -very- precisely made crankshafts instead of one. And don't forget the extra drive means to accurately synchronize and PTO the dual crankshafts. I'm going deaf from all the cash-register "cha-ching" here.

Advocates of IC versions of these engines noted the greatly improved cooling effect of 2 crankcases. For a steam engine, that's just horrendous heat loss. Even makes a conventional single-acting steam engine look good in comparison.

Twice as much [or more] piston ring length and steam blowby/leakage/loss for a given displacement and set of leak parameters (pressure differential, cyclic rate, piston speed, etc. ).

Overall, it looks to me like another "mechanical oddity which should remain a rarity".

Personally, I'd actually pay -more- for a good traditional double-acting engine than for one of these. But I think that a good DA engine can be built for a _fraction_ of the opposed-piston engine's cost.

I'm not sure whether your point here is "cost no object" or "this is affordable". The two don't quite mix.

There are a --lot-- more possibilities out there than talking, "parking lot dribblers", flashing/wasting supertankers full of cash, and steamboats. Personally, I am now attempting a low-cost -and- enjoyable/practical roadworthy modern steam automobile. A worthy challenge, I think.

I can afford to spend much more on a steam car, but I don't think that is necessary for excellent results -- nor does money guarantee results. I don't like to waste money. Plus, the low-cost potential of steam cars is well worth exploring IMO. That will turn a lot more heads than some gold-plated demo car.

As Bill Gatlin said, "I'm not quitting".

Steamboats are cool, but on the water, actually I prefer sails.

BTW, do you know what BOAT stands for? "Bust Out Another Thousand". LOL

In fact, Peter Barrett, Ted Pritchard, and many others have written at length about the lower cost and design/build difficulty of a well-designed steam car -- relative to many other types of projects. Barrett once noted that he put less time and money into one of his roadworthy steam cars than his next-door neighbor put into a replica miniature locomotive. Pritchard built his steam car himself on obsolete machine tools which were soon after sold for scrap.

And their steam cars were far more complex and experimental than the one which I am working on.

Fuel and environmental issues are moot with steam, because steam power systems can be built/modified to use a wide range of biofuels -- or conventional fuels.

IMO, the steam car is far from "one-shot last-chance" status.

Convincing IC engine makers of the value of steam power? Well, good luck with that.

Peter



Edited 2 time(s). Last edit at 02/13/2011 03:14AM by Peter Brow.
Re: Opposed piston-opposed cylinder engine
February 13, 2011 11:28AM
following this thread made me think of this song

[www.youtube.com]

(is there a way to embed video?)
Re: Opposed piston-opposed cylinder engine
February 13, 2011 02:15PM
Peter,

The opposed piston engine is not THE engine, it is however, a very good and usable concept worthy of deep and intense consideration.
IC cooling has nothing to do with it. What does, is LESS heat losses, perfect balance, adaptable packaging, great exhaust porting, plus good short cutoff ability as a steam engine.
Twice as many pistons and rods? Not if it is an ordinary SA and you then have six pistons for smooth and reliable starting without simpling valves.
The interconnecting shaft, splined slip joint and spiral bevel gears are below the cost radar, there but not serious. Off the shelf from Dyna and the nearest lathe.
Crankshafts are ALWAYS precision made, anyhow, several for this design using three or four cylinders are off the shelf and cheap.
Piston ring leakage is totally controllable when you know how to design them, use them and lube them properly.
If you are happy with 15-20 lb. water rates, large bulk and weight and slow speed, then stick to DA two cylinder engines. I am not.
Buy the book and learn.

Cost is no object and affordable depends on what scale you support Rankine cycle vehicle power, doesn't it.
There are several things that can be wasted when introducing an engine or operating cycle that has previously been rejected. Money, people, facilities, lack of knowledge of previous history, a closed mind due to ignorance and lack of skill in engineering design. What cannot be wasted is time, the one thing you cannot reverse, the rest are reversible.

Diesels and SI engines can and have run on a wide range of fuels. Today at what cost and complication? Very high because of government mandates that dictate the mileage, fuels and their pollution potential, this ignorant push for alcohol, hybrids and BEVs. Hardly a moot point at all today; but a commanding and interfering influence.
Rankine cycle engines can and have run on the same fuels and even more without any computer controlled fuel or engine management systems and they are inherently cleaner as has already been well demonstrated.
You have no idea what serious damage that government sponsored Clean Air Car program did to the Rankine cycle power source. It is going to take one hell of a lot better car than one with a Stanley engine on a Columbia rear end, or some other parking lot dribbler to make any impression today.

Until a really good steamer is actually built and can be demonstrated and shown, it remains as decades long talk, posturing, whining and no action and no hardware.
What such a car shows is not what Detroit will grab with open arms; but what the politicians see is an alternate to the present garbage. It isn't going to be the auto industry that may or may not see the light, it is the specialty car builders that may possibly want such an engine. First to sell to the wealthy sports car buyers, the types that now pay gladly for the Bugatti Vyron at $2.4M each and more important, to the big truck and industrial markets that right now are facing such condemnation of their Diesel engines. This is not stopping; but accelerating, so showing such a good Rankine cycle power source might just cause more than simple interest.

Jim
Re: Opposed piston-opposed cylinder engine
February 13, 2011 02:54PM
One question people always ask me when I tell them I'm a steam enthusiast is "If steam is so good then why aren't there any steam cars on the road?"

Why is it that there are internal combustion engines coming out of the woodwork in every shape and form that's ever been imagined, but no one, anywhere, has made a steam car. Not even an efficient steamcar, just one that works reliably.

Edit 1: (Obviously cars made over 70 years ago are excluded)

Van



Edited 1 time(s). Last edit at 02/13/2011 07:31PM by vandallas.
Re: Opposed piston-opposed cylinder engine
February 14, 2011 10:50AM
Van,

This is one huge subject and one that needs to be fully explored via our SACA Journal in several issues. It is only possible to hit a few highlights in this post.

People do not make steam cars today, because most of them who enjoy and know what steam can offer in a vehicle are still wallowing in the old technology and are simply not well educated enough in the difficult engineering that a really modern steam car demands, or cannot afford the next step. As is so often seen, too many just do not know what it takes and love to pontificate on how good their ideas are, when they do not exist as hardware that can be tested on a dyno and usually never will. Without that, it remains an interesting hobby one talks about; but does nothing to further the art. It takes a very serious commitment and a ton of money and time to build, test and develop a really modern Rankine cycle power system for a car. There is also the situation for many who do manage to make a steamer, that good enough and if it simply manages to run at all, is as far as one needs to go. Wrong, definitely wrong.

Also, no one will put corporate funds into even investigating the Rankine cycle today and damn few have the private means to do this and start developing a really competitive car power system, it takes millions to do it right and a good support staff. No one for sure knows all the answers personally, we are all still learning.
The vast bank of knowledge we had in the 1920-1950 era is now very hard to find, most does not exist where any responsible car builder can even find it if he even wanted to. The colleges do not teach Rankine cycle technology any more like they used to, only now as it relates to huge power plants and Navy ship propulsion and ocean liners. Even there the Diesel rules.

The old steamers from 1899 to 1940 were good enough for their day and some were actually quite competitive to the prevailing gas cars.
What really helped kill the steamer was when Cadillac introduced the electric self starter in 1912 in the Model 30. Now anyone could start his or her car with no effort and this one thing now opened up the power potential of the IC engine. That and an intense effort to remove the problems the IC engine had, made for very rapid improvement and almost complete public acceptance of the gas car. The old steam car companies managed to commit suicide all by themselves by not improving their products, or is it suttee?
The Stanleys never entered even the 20th century with their cars. Papa White shut down the steam cars in 1910, and they built a few into 1913 to use up the parts. Abner Doble couldn't keep his hands off the cars and constantly changed things, plus the two big stock fraud trials, put an end to Doble Steam Motors Inc. Besler made the F Doble; but only seven of them, then the Kaiser and the G.M. car more for fun than anything more serious. In spite of his warnings not to take steam cars seriously, he couldn't keep his hands off them. Williams did themselves in with their paranoia. Leslie, Blakeborough, Moulton were one shot deals. Greyhound, Clever-Brooks and Stanley suffered from Abner's extravagance and always using the customer's money to try out new ideas. McCulloch ended things from a business point of view and having to deal with Abner's arrogance and the rest only managed one or two prototypes, if even that.

You really have to study what went on during that government sponsored Clean Car program from 1959 to about 1985. Because of deliberate government and auto industry intent and collaboration, steam was buried for all times, at least that is what they wanted and in the end got. The publicity damage was total, steamers burn fuel at a great rate, are unreliable and no one can make a successful one today. That was the message and after Lear's failure, the best one for B...S... publicity ever seen, everyone believed it.
At dinner one night Bob Lutz told me directly: "We all watched the program with great interest; but when not one successful car came out of that program, we, the auto industry, consider steam cars to be non existent. For us, steam does not even exist."
Besler's Chevy conversion for G.M. was reliable and was driven from Emeryville to Los Angeles twice with no problems; but it was not all that fuel efficient. The Williams Bros. had a good car for the time; but their paranoia for keeping their work secret kept them out in the loony-toony fringe where most people put all steam car enthusiasts.

In those days, 750-850* F was as high a superheat you dared use, because the injected cylinder oil carbonized and made a mess inside the steam generator tubing (carbon) and in the condenser and water tank. In those days, not one developer ever mentioned not using this oil and doing it by using the working fluid, water.

What happened recently was one person sat down and listed all the good advantages of what the Rankine cycle can bring to vehicle propulsion. We all know what those are.
OK, so here sits Harry Schoell who did exactly that one study, then put his money where his mouth is and started in. He established six absolute truths that when implemented, would make the Rankine cycle engine not only up to date for the 21st century; but actually competitive to any IC engine. Of course he made mistakes, we all do; but he kept on and eliminated what went wrong and forged ahead. Not one other person or firm has taken this big a step to my knowledge.
Now some five years later and over $4M dollars, he is sitting on the verge of commercial success. His firm is the only one I can point to who have actually done this.
One also sees today, the very suspicious promotion efforts to fund some steam engine idea. Quite identical to what went on during that Clean Car business, they were in the government grant harvesting business, not the steam car business.

It is very hard to ignore 32% net cycle efficiency and complete pollution free combustion when burning bio fuel oils.
This is why I put all my work on the shelf and completely support the Cyclone effort. If the company does not succeed commercially, then steam is truly dead and will remain only as a nice and very interesting hobby. I tried to make some sense of all this and John Woodson kindly printed the blab on his web site. stanley steamers.com

Jim



Edited 2 time(s). Last edit at 02/14/2011 08:56PM by Jim Crank.
Re: Opposed piston-opposed cylinder engine
February 14, 2011 01:06PM
Jim,

Thanks a lot for the response, I've been trying to scavenge for information like that for months so it's nice to have it all summed up.

What were those four absolute truths?

It seems to me that steam's biggest challenges is the bad PR it has.

There was recently a psychological study done that showed the less someone knows on a subject, the more they can delude themselves into thinking they know about it.

Whenever I get asked questions about steam technology people seem to think IC is more efficient because fuel is burned right in the cylinder.

Between the stigma the rankine cycle faces, along with the difficulty of learning its "secrets" it is small wonder steam is circling the drain.

I've spent the last two months straight learning everything I can, avoiding parties, doing minimial school homework: I've barely come any closer to learning anything that will aid in my beemer conversion.

Maybe I'll just sit on my hands until I can buy a cyclone.

Van
Re: Opposed piston-opposed cylinder engine
February 14, 2011 04:55PM
Van,

You cannot imagine what the bad publicity, snickering and general ignorance did to any possible steam car project from then on. A good number of the steam car enthusiasts made such fools of themselves in public that they really dragged the whole idea down. Bob Lutz was hard and blunt; but accurate at that time.
For example: At the California Highway Patrol steam car meeting, (really, they had a few, supposed to be part of the Clean Car program) two characters from Los Angeles actually proposed two Stanley boilers and burners and a Stanley 30 hp engine and they were serious too. The only time I saw Besler lose his composure and laugh out loud at an otherwise serious meeting. Howled all the way home too in the car. For weeks all I had to say was "Two Stanley boilers" and the laughing started all over again.

The damage in Detroit and in the minds of the general public was complete. I watched it all happen, as a consultant during the steam bus program, Roy Renner and I were assigned the Lear bus project. I was firmly told to keep my mouth shut and not say anything, which is not my usual behavior. Lear was greatly lied to and deluded by Ken Wallis, until he got wise and fired him. Bill Lear himself didn't know which end to put the match in and Wallis sure took advantage of this.
Then I worked with Del Hood and he not only was a pleasure to work with; but knew his business. I really wanted to work on the Broebeck bus project as he was one sharp engineer and knew steam like the back of his hand. Right down the street from Besler's play pen. They were good friends.

Oh, the self deluded who think they know the Rankine cycle engineering and really don't. Many displayed here. Problem is Van, a lot do not know the history, who did what from an engineering standpoint and why things sometimes worked very well (White) and why not at times. Some refuse to do their research homework or don't know how or where.
That psychological study is quite right.

OK actually the six things Harry did that finally brought the Rankine cycle engine into the 21st Century and out of the 19th century it has wallowed in for decades.
Nothing really not known before; but never brought together in one engine.
Although in Europe there was a form of stationary steam engine called the "Locomobile or Locomotor" that used many of the same ideas, including serious reheat between the HP and LP cylinders. They achieved a very low water rate as a result. Not too much is known about them today. A German development if I recall correctly. Lentz??? Ben, do you know anything about these engines? I can't find the book that had quite a few described and pictured. Will keep looking.

1( Very high working pressure to greatly enhance the power and packing density. Most old ones ran between 500 to 1200 psig. This high pressure, up to 3200 psig, he uses greatly enhances the BMEP that is actually usable with his very short cutoff, like 5%.
2) The ABSOLUTELY most important. Abandoned oil injection for cylinder lubrication and used the working fluid, water. Which leads directly to:
3) Raised the superheat temperature up to as much as modern materials will stand, between 1200*F to 1400*F. What this oil removal does is remove the cap on temperature that has to be removed to get the cycle efficiency up to something that permits good fuel rates and much lower water rates. The carbon problem is now gone.
4) A very dense packaging of the whole system and not the usual spray of tubing all over the place connecting the major lumps together.
5) Actually add this one too. Combined a high compression ratio with a means of keeping that residual steam hot and not letting it lower the temperature of the incoming steam.
Along with what really goes with this too, absolute minimum usable clearance volume.
6) Paid very close attention to recovering as much heat in the engine (engine exhaust, combustion exhaust) as possible. A high percentage of recuperated otherwise wasted heat is returned to the cycle.

Then a really clean burner that when using bio fuel oils from algae, is totally pollution free and with a neutralized carbon footprint. No trick things here, just good engineering.

Don't you dare use a BMW bike, if it is an R-1000 I will buy it, always wanted one. Think of using an old Honda Gold Wing, with that opposed six cylinder engine, one of their older sport bikes without the Star Wars fairings, cheap. Lots of room in there. There is one a few blocks from me with a small block Chevy in it. Neat installation too.
Don't wait for a Cyclone, start building your bike and have a lot of fun doing it. The KISS factor please.
I have, if I can find it, a half hour of Super 8 mm sound movies of Dave Sarlin and I getting that Cliff House steam motorcycle running and riding it after he restored it. Should make a DVD out of that film and let the SACA store sell it. I doubt any other exists. One really neat and well done steam motorcycle. In the red Clymer's steam booklet and Dave did a big story in an old edition of the SACA Bulletin. Karl, can you help us here with the issue number.

Jim



Edited 4 time(s). Last edit at 02/14/2011 08:19PM by Jim Crank.
ben
Re: Opposed piston-opposed cylinder engine
February 14, 2011 05:51PM
Hi Jim,,,Diff spelling,,,Lanz,,,,and the English,,,Clayton-Shuttleworth,,,Not sure if these are the ones you are lookin for,,,,Re BMW,,How about a R69S,,,in stock,,some assy reqd,,long story,,,
Item #3,,Sylvester Marsh,Brockton Mass,,built a compound w/inter stage reheat,,around 1900,,,the patent drawings shew it,,reserch I did 10 years ago[1990] oh well,,
Van,,,remember,,,,,TIME is the enemy,,,Cheers,,Ben
Re: Opposed piston-opposed cylinder engine
February 14, 2011 08:35PM
Jim,

A feature of the cyclone not mentioned, and I believe is quite helpful in the end thermal efficiency is the crank geometry native to a radial engine. Exploited, is significant, and not something to be ignored. -Keith
Re: Opposed piston-opposed cylinder engine
February 14, 2011 11:19PM
Jim

What modifications are necessary to use water as the lubricant. I recall a few posts about coating the cylinders? But they might have been talking about something else.

How does the Cyclone control cut off? I read it used needle valves but were they custom built?

What is the superheater material comprised of? 316 seamless? What is the diameter?

I really hope the Cyclone takes off, to have pulled together all the little nuggets of information on Rankine and combine it into an engine must have been a daunting task, I only hope one day more people will be able to emulate it.

Van
Re: Opposed piston-opposed cylinder engine
February 16, 2011 07:34AM
Even better, could someone point me to where I can read about super critical generators? I've read several old textbooks on steam, archive.org has been particularly helpful but they don't really speak about the two things that are essential, super critical temperatures, and water as a lubricant. So any direction would be greatly appreciated.

Van
ben
Re: Opposed piston-opposed cylinder engine
February 16, 2011 08:25AM
From very old and tired memory,,Seems I recall Lehigh University doing work on Hi temp pressure stuff,,I think there was more on this before NUC plants,,,,,,Hey Rolly,,c'mon over,,,the dew point is --04 this mornin,,,Ben
Re: Opposed piston-opposed cylinder engine
February 16, 2011 09:23AM
Good Morning Ben
75F this morning

Van Google supercritical steam there’s all kinds of stuff on the internet.
Supercritical steam is 3208 PSI and above at 705 F and above.
All the fossil fuel power plants I have worked on run 3600 PSI at 1200 F
Rolly
Re: Opposed piston-opposed cylinder engine
February 16, 2011 10:02AM
Apparently supercritical water is very corrosive, what special considerations are there to take in when dealing with it?

Van
Re: Opposed piston-opposed cylinder engine
February 16, 2011 01:04PM
316 SS is happy with it.
Re: Opposed piston-opposed cylinder engine
February 16, 2011 03:11PM
That's good news.

What about cylinder coatings? I remember someone talking about nikasil.

Van
Re: Opposed piston-opposed cylinder engine
February 16, 2011 06:59PM
Van,

Don't go to supercritical unless you are after the ultimate power density you can possibly have.
In a bike, 1200-1500 psig is more than enough.

Jim
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