Williams ws. Rankin
Posted by Howard Langdon
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Re: Williams ws. Rankin October 23, 2007 01:50PM |
Registered: 19 years ago Posts: 835 |
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Re: Williams ws. Rankin October 24, 2007 06:52PM |
Registered: 19 years ago Posts: 318 |
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Re: Williams ws. Rankin October 24, 2007 08:09PM |
Registered: 19 years ago Posts: 835 |
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Re: Williams ws. Rankin November 10, 2007 07:26PM |
Registered: 19 years ago Posts: 318 |
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Re: Williams ws. Rankin November 13, 2007 11:48AM |
Registered: 19 years ago Posts: 318 |
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Re: Williams ws. Rankin November 13, 2007 12:21PM |
Admin Registered: 18 years ago Posts: 2,107 |
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Re: Williams ws. Rankin November 15, 2007 10:39AM |
Registered: 19 years ago Posts: 318 |
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Re: Williams ws. Rankin November 27, 2007 02:33PM |
Registered: 17 years ago Posts: 124 |
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Re: Williams ws. Rankin September 23, 2008 09:01PM |
Registered: 19 years ago Posts: 318 |
HI Guys the Williams tests is still going on. There are moor problems van you would believe. And sum of vem wor. Political. We have had good luck should go better now. I will post the members as soon as soon as can. The old test gave an 8.5-pound rate on the 264-engine and the56 a 6.44 rate.
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Re: Williams ws. Rankin November 27, 2008 11:43AM |
Admin Registered: 18 years ago Posts: 2,107 |
Hi folks:
I've seen the Williams bus engine a few times in Tom Kimmel's shop. I've also seen the paper Jerry wrote about it for the last SACA meet. Now I've found the long, lost patent. Problem is, the application was filed in 1905, issued in 1907, the guys name was MacLachlan and the company was the Detroit Steam Engine Co. Go to www.google.com/patent and examine US Patent # 863545.
This is the same darn engine. Tee shaped chamber at top of cylinder, uniflow belt exhaust, separate admission and exhaust poppets driven by separate sliding cams. Only thing the Williams had was a cross head; not necessarily an improvement to a single acting engine in my opinion unless you really like more reciprocating mass, higher stresses, greater overall weight and volume.
Kinda ironic that the guys who were so secretive about their work, lest it be stolen, were developing something that had been in the public domain since about 1925. I doubt they could ever have sucessfully protected that design in court if opposing counsel found this patent.
Regards,
Ken
I've seen the Williams bus engine a few times in Tom Kimmel's shop. I've also seen the paper Jerry wrote about it for the last SACA meet. Now I've found the long, lost patent. Problem is, the application was filed in 1905, issued in 1907, the guys name was MacLachlan and the company was the Detroit Steam Engine Co. Go to www.google.com/patent and examine US Patent # 863545.
This is the same darn engine. Tee shaped chamber at top of cylinder, uniflow belt exhaust, separate admission and exhaust poppets driven by separate sliding cams. Only thing the Williams had was a cross head; not necessarily an improvement to a single acting engine in my opinion unless you really like more reciprocating mass, higher stresses, greater overall weight and volume.
Kinda ironic that the guys who were so secretive about their work, lest it be stolen, were developing something that had been in the public domain since about 1925. I doubt they could ever have sucessfully protected that design in court if opposing counsel found this patent.
Regards,
Ken
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Re: Williams ws. Rankin November 28, 2008 09:43AM |
Registered: 19 years ago Posts: 1,441 |
Ken,
Also read the last chapter in Stumpf's unaflow book. He takes time to describe how high compression takes the load off the inlet poppet valve and makes single seated ones practical.
What this patent does not say, is if they used any automatic compression relief valve, as Williams did. This I saw in Tom Kimmel's photographs.
Sort of like some guy years ago at a SACA meet in Los Angeles. With great secrecy he told me about his invention for a double acting steam engine with no crosshead.
That orbiting planet gear inside a large gear thing.
Well, during a visit to the Ford Museum, rounding a corner, there it was in a big upright engine. Try 1805!!!
Equate secrecy with paranoia.
Jim
Also read the last chapter in Stumpf's unaflow book. He takes time to describe how high compression takes the load off the inlet poppet valve and makes single seated ones practical.
What this patent does not say, is if they used any automatic compression relief valve, as Williams did. This I saw in Tom Kimmel's photographs.
Sort of like some guy years ago at a SACA meet in Los Angeles. With great secrecy he told me about his invention for a double acting steam engine with no crosshead.
That orbiting planet gear inside a large gear thing.
Well, during a visit to the Ford Museum, rounding a corner, there it was in a big upright engine. Try 1805!!!
Equate secrecy with paranoia.
Jim
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Re: Williams ws. Rankin November 28, 2008 02:07PM |
Admin Registered: 18 years ago Posts: 2,107 |
Hi Jim:
I love the epicyclic engine at the Henry Ford Museum, hard to not love the concept just based on how much sheer fun it had to be to watch that thing spinning around. Of course, I think some steam engines basically justify their existence more on their value as kinetic sculpture.
This patent didn't seem to have the Williams relief valve that I've seen in the bus engine, but I don't think it was all that important...in this specific incarnation. In the earlier Williams engines you definitely needed some means of preventing overcompression, and since they didn't use subatmospheric exhaust the relief was about the only way to go.
In the bus engine (and this patent) you have a second exhaust valve with a sliding camshaft. Properly used this camshaft should prevent overcompression, making the relief moot. Only took a few seconds to sketch up a very simple control mechanism that would control the compression, certainly nothing as complex as a Doble "Quad" thermostat.
Not always easy to figure out where secrecy ends and paranoia begins, even paranoids can have enemies. The Williams definitely slid past the boundry line into full fledged paranoia, however, as it appears they made security an end in and of itself rather than just a function of achieving their goals.
Regards,
Ken
I love the epicyclic engine at the Henry Ford Museum, hard to not love the concept just based on how much sheer fun it had to be to watch that thing spinning around. Of course, I think some steam engines basically justify their existence more on their value as kinetic sculpture.
This patent didn't seem to have the Williams relief valve that I've seen in the bus engine, but I don't think it was all that important...in this specific incarnation. In the earlier Williams engines you definitely needed some means of preventing overcompression, and since they didn't use subatmospheric exhaust the relief was about the only way to go.
In the bus engine (and this patent) you have a second exhaust valve with a sliding camshaft. Properly used this camshaft should prevent overcompression, making the relief moot. Only took a few seconds to sketch up a very simple control mechanism that would control the compression, certainly nothing as complex as a Doble "Quad" thermostat.
Not always easy to figure out where secrecy ends and paranoia begins, even paranoids can have enemies. The Williams definitely slid past the boundry line into full fledged paranoia, however, as it appears they made security an end in and of itself rather than just a function of achieving their goals.
Regards,
Ken
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Re: Williams ws. Rankin November 28, 2008 07:06PM |
Registered: 19 years ago Posts: 1,519 |
The thing that really makes me raise an eyebrow here, is the fact that Otto engines or variations of such, like a Diesel engine, (or, proposed 4-cycle steam) use no,'any automatic compression relief valve'. With exception to any sort of starting compression relief. Such as an 'easy-spin lobe' on a briggs and stratton camshaft. But such an modification to make starting easyier with moderate to high compression ratio, is not suppose to affect performance within the powerband range.
Also, would really like to understand the difference between a sliding camshaft, and sliding valve gear. I realize changing the link-motion on an eccentric for driving the sliding valve gear, is an easy way to effect cutoff.
Jeremy
Also, would really like to understand the difference between a sliding camshaft, and sliding valve gear. I realize changing the link-motion on an eccentric for driving the sliding valve gear, is an easy way to effect cutoff.
Jeremy
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Re: Williams ws. Rankin November 28, 2008 10:16PM |
Registered: 19 years ago Posts: 1,441 |
Ken,
That Williams automatic compression relief valve was very important. It did prevent over compression as you said. But; without any other mechanism and was so simple. It keeps cylinder compression matching the inlet pressure, even with a high mechanical compression ratio.
Their paranoia simply made fools of them to the government. They shot themselves in the foot, when they really had something of worth.
Jeremy,
You don't want any such relief valve on an IC engine. The PV events would be badly harmed with one. Starting a huge engine is one thing, like my 1100 cu/in American La France fire truck engine. Using it in the operating cycle is not at all where you want one.
What's the problem with seeing how sliding works?
The cam has several lobes with either different lift or different degree of timing for the inlet valve, how long it holds it open, or how much lift for the valve. You simply slid the cam from lobe to lobe. That transition between lobes is not easy to make at home. Used with poppet valves.
The sliding or shifting eccentric varied the amount of eccentricity and thus varied how much the valve was opened. With a piston valve or a slide valve, it determined the stroke of the valve and thus the cutoff. Besler used one on many of his engines, both airplane engines and the Chevy conversion.
Much simpler than any link valve gear and with fewer parts.
Jim
That Williams automatic compression relief valve was very important. It did prevent over compression as you said. But; without any other mechanism and was so simple. It keeps cylinder compression matching the inlet pressure, even with a high mechanical compression ratio.
Their paranoia simply made fools of them to the government. They shot themselves in the foot, when they really had something of worth.
Jeremy,
You don't want any such relief valve on an IC engine. The PV events would be badly harmed with one. Starting a huge engine is one thing, like my 1100 cu/in American La France fire truck engine. Using it in the operating cycle is not at all where you want one.
What's the problem with seeing how sliding works?
The cam has several lobes with either different lift or different degree of timing for the inlet valve, how long it holds it open, or how much lift for the valve. You simply slid the cam from lobe to lobe. That transition between lobes is not easy to make at home. Used with poppet valves.
The sliding or shifting eccentric varied the amount of eccentricity and thus varied how much the valve was opened. With a piston valve or a slide valve, it determined the stroke of the valve and thus the cutoff. Besler used one on many of his engines, both airplane engines and the Chevy conversion.
Much simpler than any link valve gear and with fewer parts.
Jim
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Re: Williams ws. Rankin November 28, 2008 11:28PM |
Registered: 19 years ago Posts: 1,519 |
Hi Jim,
I noticed your post after mine to the RV/whatever post.
Look man, I just took a swigg out of a 1.5 day old beer setting on my back porch before I could find my fresh beer, pretty sure that I will live, but figured Id mention It because I thought Peter B, would get a kick out of that...
"What's the problem with seeing how sliding works?
The cam has several lobes with either different lift or different degree of timing for the inlet valve, how long it holds it open, or how much lift for the valve. You simply slid the cam from lobe to lobe. That transition between lobes is not easy to make at home. Used with poppet valves.
The sliding or shifting eccentric varied the amount of eccentricity and thus varied how much the valve was opened. With a piston valve or a slide valve, it determined the stroke of the valve and thus the cutoff. Besler used one on many of his engines, both airplane engines and the Chevy conversion.
Much simpler than any link valve gear and with fewer parts. Jim C"
I dont like elipical waveforms, they seem sinusoidal to me like a 3phase waveform. I preffer a squarewave waveform.
"Much simpler than any link valve gear and with fewer parts."
When I first saw Harrys valve control mechanism, I thought there were to many parts. This is why I preffer direct-lift injection valve geometry. It is very different than a poppet valve design.
Also, I have studied Harry's CRM, and I dont think such a thing should be married to the injection system,
(not to mention the 90* angles involved, which are a no-no) in anyway.
"Jeremy,
You don't want any such relief valve on an IC engine The PV events would be badly harmed with one."
Please specify 'PV' events.
Jeremy
I noticed your post after mine to the RV/whatever post.
Look man, I just took a swigg out of a 1.5 day old beer setting on my back porch before I could find my fresh beer, pretty sure that I will live, but figured Id mention It because I thought Peter B, would get a kick out of that...
"What's the problem with seeing how sliding works?
The cam has several lobes with either different lift or different degree of timing for the inlet valve, how long it holds it open, or how much lift for the valve. You simply slid the cam from lobe to lobe. That transition between lobes is not easy to make at home. Used with poppet valves.
The sliding or shifting eccentric varied the amount of eccentricity and thus varied how much the valve was opened. With a piston valve or a slide valve, it determined the stroke of the valve and thus the cutoff. Besler used one on many of his engines, both airplane engines and the Chevy conversion.
Much simpler than any link valve gear and with fewer parts. Jim C"
I dont like elipical waveforms, they seem sinusoidal to me like a 3phase waveform. I preffer a squarewave waveform.
"Much simpler than any link valve gear and with fewer parts."
When I first saw Harrys valve control mechanism, I thought there were to many parts. This is why I preffer direct-lift injection valve geometry. It is very different than a poppet valve design.
Also, I have studied Harry's CRM, and I dont think such a thing should be married to the injection system,
(not to mention the 90* angles involved, which are a no-no) in anyway.
"Jeremy,
You don't want any such relief valve on an IC engine The PV events would be badly harmed with one."
Please specify 'PV' events.
Jeremy
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Re: Williams ws. Rankin November 29, 2008 12:45AM |
Registered: 19 years ago Posts: 1,519 |
Hi All,
"Look man, I just took a swigg out of a 1.5 day old beer setting on my back porch before I could find my fresh beer, pretty sure that I will live, but figured Id mention It because I thought Peter B, would get a kick out of that... Jeremy"
So anyway, Ive decided that drinking more beer will help.
Sorry,
Ive been really upset lately. Ive had this Red Tabby cat for over 22 human years. Whats that, like 140 cat years?...
I have to take him to the vet, this coming monday, im very upset about this, since I know the cat has cancer. Its the last I will ever see of old 'Tom Cat'. This has been coming, and has been bothering me for awhile. So my, intensity, is most likely from what I will have to face, and am trying to get yoused to. Oh well nevermind... I know that this will sound strange to the newbies.
I have attached 2 pictures
Best
Jeremy
"Look man, I just took a swigg out of a 1.5 day old beer setting on my back porch before I could find my fresh beer, pretty sure that I will live, but figured Id mention It because I thought Peter B, would get a kick out of that... Jeremy"
So anyway, Ive decided that drinking more beer will help.
Sorry,
Ive been really upset lately. Ive had this Red Tabby cat for over 22 human years. Whats that, like 140 cat years?...
I have to take him to the vet, this coming monday, im very upset about this, since I know the cat has cancer. Its the last I will ever see of old 'Tom Cat'. This has been coming, and has been bothering me for awhile. So my, intensity, is most likely from what I will have to face, and am trying to get yoused to. Oh well nevermind... I know that this will sound strange to the newbies.
I have attached 2 pictures
Best
Jeremy
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Re: Williams ws. Rankin November 29, 2008 09:02AM |
Registered: 19 years ago Posts: 1,441 |
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Re: Williams ws. Rankin November 29, 2008 10:10AM |
Admin Registered: 18 years ago Posts: 2,107 |
Hi Jim:
I agree the relief was important on earlier engines. The bus engine, by contrast, potentially has variable compression; the exhaust valve in the cylinder head can close at different points in the stroke. As admission pressure goes down the engine should shift the exhaust cam to later and later closing, reducing the compression ratio and thus the recompression pressure. A spring loaded cylinder operated by admission pressure could progressively slide the camshaft and keep the recompression pressure close to the admission pressure. Done properly, you should never see excess compression and the relief valve would be moot.
I'm not sure exactly how the Williamses DID use the cam, I couldn't find any definitive clues from the engine in Tom's shop. Could be the control mechanism was mounted to the vehicle rather than integral to the engine. Possibly they just used the cam to assist self starting and low rpm operation and then reverted to pure uniflow at higher steam conditions. If so, then the relief valve would be necessary.
Regards,
Ken
I agree the relief was important on earlier engines. The bus engine, by contrast, potentially has variable compression; the exhaust valve in the cylinder head can close at different points in the stroke. As admission pressure goes down the engine should shift the exhaust cam to later and later closing, reducing the compression ratio and thus the recompression pressure. A spring loaded cylinder operated by admission pressure could progressively slide the camshaft and keep the recompression pressure close to the admission pressure. Done properly, you should never see excess compression and the relief valve would be moot.
I'm not sure exactly how the Williamses DID use the cam, I couldn't find any definitive clues from the engine in Tom's shop. Could be the control mechanism was mounted to the vehicle rather than integral to the engine. Possibly they just used the cam to assist self starting and low rpm operation and then reverted to pure uniflow at higher steam conditions. If so, then the relief valve would be necessary.
Regards,
Ken
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Re: Williams ws. Rankin November 29, 2008 11:52AM |
Registered: 19 years ago Posts: 1,268 |
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Re: Williams ws. Rankin November 29, 2008 11:57AM |
Registered: 19 years ago Posts: 68 |
Thanks for the details of the Williams engine everyone. I had not understood why the compression relief valve was needed as the inlet poppet valve by balancing head diameter vs steam and spring pressure could possibly serve the same function?
But controlling the exhaust cam now that's interesting.
Better dig through my files and see what I've forgotten.
Cheers
Mark
But controlling the exhaust cam now that's interesting.
Better dig through my files and see what I've forgotten.
Cheers
Mark
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Re: Williams ws. Rankin November 29, 2008 12:52PM |
Registered: 19 years ago Posts: 1,268 |
Hi Guys,
Didn't Jerry Peoples come up with an automatically varying clearance which used a constriction before an auxiliary clearance chamber. What this would do is provide a larger clearance at low RPM for easy running and negate itself at higher RPMs. Wouldn't this function similarly to exhaust relief?
My concern is a pressure relief that can process some water slug that might make it into the engine but wouldn't a unaflow be less sensitive to water slugs?
I know, just stay away from places where water slugs grow.
Best, ---- Bill G.
Didn't Jerry Peoples come up with an automatically varying clearance which used a constriction before an auxiliary clearance chamber. What this would do is provide a larger clearance at low RPM for easy running and negate itself at higher RPMs. Wouldn't this function similarly to exhaust relief?
My concern is a pressure relief that can process some water slug that might make it into the engine but wouldn't a unaflow be less sensitive to water slugs?
I know, just stay away from places where water slugs grow.
Best, ---- Bill G.
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Re: Williams ws. Rankin November 29, 2008 05:55PM |
Admin Registered: 18 years ago Posts: 2,107 |
I just got a memo from Tom Kimmel, his understanding is that the Williams bus engine uses the aux exhaust valve for counterflow operation when starting and running in long cutoff and shifts to pure uniflow at shorter cutoff...though he says he isn't sure he can verify that from direct observation. I'll buy that as it would give the Williams style cylinder head relief valve a reason for existing.
I still maintain the relief valve isn't necessary for the MacLachlan engine if he used the aux exhaust valve to control recompression level. Call me pigheaded, but I ran a number of cycle 'what-if' analyses with this being one of the scenarios for engine control and it always came out valid.
Tom also asked me to note that Jim Tangeman’s tractor is illustrated and written up in the May-June 2006 Vol 20 No 3 issue of the SACA Bulletin and that the Worthington boiler Jim's boiler is based on is in the most recent Vol 22 No 6 issue.
Regards,
Ken
I still maintain the relief valve isn't necessary for the MacLachlan engine if he used the aux exhaust valve to control recompression level. Call me pigheaded, but I ran a number of cycle 'what-if' analyses with this being one of the scenarios for engine control and it always came out valid.
Tom also asked me to note that Jim Tangeman’s tractor is illustrated and written up in the May-June 2006 Vol 20 No 3 issue of the SACA Bulletin and that the Worthington boiler Jim's boiler is based on is in the most recent Vol 22 No 6 issue.
Regards,
Ken
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Re: Williams ws. Rankin November 29, 2008 07:25PM |
Registered: 19 years ago Posts: 318 |
HI Guys the Williams twins worn the most paranoid people I ever new the different. I Kant say more on line, as I have to work worve vim now you no why the test is taking so loran, and why I and Ton are billing and a engine on owne. HI Guys the Williams twins worn the most paranoid people I ever new the different. I Kant say more on line, as I have to work worve vim now you no why the test is taking so loran, and why I and Ton are billing and a engine on owne.
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Re: Williams ws. Rankin November 29, 2008 10:35PM |
Registered: 19 years ago Posts: 1,453 |
One of my favorite quotes on paranoia is "just because you're not paranoid, doesn't mean 'They' are NOT out to get you". LOL
I think that paranoia in moderation is a good thing. You know how many patents there are, designing/building leaves little time to search through 100,000s of them, including foreign patents, and professional patent researchers cost a fortune and even the top ones often miss things, as they did with my one and only US patent application in 1979, "application denied, game over" $1500 later. [digression omitted peb]
Anyway, the point being that patent searches are laborious, unreliable, and/or expensive, so personally I don't necessarily think less of somebody who (incorrectly) thinks their idea is (or might be) original, and perhaps worth extraordinary secrecy. Then again, secrecy *can* get out of hand ... details on exactly how are strictly "classified", of course ...
Ken, I think there are 2 types of steam car guys: pigheaded ones, and the ones who never settle on a design long enough to build something. I've spent enough years being the latter, now trying the former. The difference in practical results between one design and another is sometimes so small that I think pigheadedness isn't always much of a problem. Oh gosh, you get 2 mpg less, or it took an extra year or $1000 more to work out, because you were such a pighead on some pet technical detail. Big deal. As long as you get something built and running, and are having fun. If being pigheaded helps get you there, then that's a good thing. Say what ye will about pigs, but they do have lots of oinky muddy fun.
Jeremy, thou takest my name in vain! Hang in there on the cat situation. It is a hard thing to deal with. I went through the same thing with my 20 year old feline assistant in June. Beer helps. Fresh beer, that is. Fresh saves on cleaning up the mouth spray afterwards. All things in moderation. Including moderation itself. I need to adopt a couple new family members, but kittens plus christmas tree equals trouble. Darned cute when they curl up asleep among the scattered ornaments underneath it, though.
===============
Getting a little less unsteamly: I am very conscious of the effects of running with a cold engine, when choosing engine valve system & control features. With cold metal sucking heat/pressure out of the steam, residual exhaust recompression will be lower for a given inlet pressure, compared to hot-engine results, for one thing. With ultralow clearance volume and low exhaust release pressures (idling?), warmup condensate may cause problems too. I have wondered whether a well-insulated engine cools more/faster when idling at low pressure than when coasting to a stop and sitting -- and engines do warm up faster under load (doing work in the process) than when idling.
On the Williams engine, they did claim 30 mpg from their roadster, but I wonder what percentage of road time was devoted to running in "rankine mode", with the auxiliary exhaust and late cutoff. A Williams-like engine _might_ have a shot at higher actual efficiency in highway cruising, if the engine is carefully sized for the vehicle. Big engine for hi HP, plus "it's Williams so its efficient", I'm not sure. There are often big differences in mpg/efficiency with different-sized IC engines in the same car; I don't think that "an" engine has "an" efficiency.
And often efficiently-sized/designed engines don't sell -- or in our case aren't pleasing to the efficiency-minded hobbyists who built them -- due to lower performance. Cost is a factor too. My Bug costs a fraction as much per mile, overall, as far more fuel-efficient cars, due to the cheap and primitive tech on board. Even when fuel prices were spiking toward traditionally European levels earlier this year. Anyway, these are a few of the things I've been pondering and looking out for.
I got my new Bulletin yesterday, and noticed that Peter Pellandine has finally found a good grind for his cams for smooth and quiet running. Wanted to mention this to update my previous remarks in another thread.
Jim, I have looked into shifting eccentrics. These can be simpler than linkage valve gears, one less eccentric per valve sure would be nice, but it takes more development work (design, build, test, redesign, rebuild, retest, etc) to get the actuation and timing right with any experimental valve gear (even if it a proven type), than just brazenly plagiarizing Stephenson geometry from Stanley blueprints. Also, I have read that many professional outfits ran into long-term durability issues with shifting eccentrics in locomotives. For an amateur designer/builder like me, the odds of durability and timing/actuation problems with an experimental valve gear design look lots higher than for the pros. In my case, with this first-build project, I prefer the extra machine work (already planned out for my machine tools) to get as close as I can to a road-tested design, sooner.
If/when I get everything else running, I can get more experimental, including other valve gear and valve types, for accurate "all else being equal" comparisons. My engine design is modular, and looks very conducive to experimental changes. Even the piston-to-slide valve change in May, only took me a week or two from raw concept to strength-analyzed, fully-dimensioned, and machining-planned shop drawings.
Peter
Edited 2 time(s). Last edit at 11/30/2008 03:00AM by Peter Brow.
I think that paranoia in moderation is a good thing. You know how many patents there are, designing/building leaves little time to search through 100,000s of them, including foreign patents, and professional patent researchers cost a fortune and even the top ones often miss things, as they did with my one and only US patent application in 1979, "application denied, game over" $1500 later. [digression omitted peb]
Anyway, the point being that patent searches are laborious, unreliable, and/or expensive, so personally I don't necessarily think less of somebody who (incorrectly) thinks their idea is (or might be) original, and perhaps worth extraordinary secrecy. Then again, secrecy *can* get out of hand ... details on exactly how are strictly "classified", of course ...
Ken, I think there are 2 types of steam car guys: pigheaded ones, and the ones who never settle on a design long enough to build something. I've spent enough years being the latter, now trying the former. The difference in practical results between one design and another is sometimes so small that I think pigheadedness isn't always much of a problem. Oh gosh, you get 2 mpg less, or it took an extra year or $1000 more to work out, because you were such a pighead on some pet technical detail. Big deal. As long as you get something built and running, and are having fun. If being pigheaded helps get you there, then that's a good thing. Say what ye will about pigs, but they do have lots of oinky muddy fun.
Jeremy, thou takest my name in vain! Hang in there on the cat situation. It is a hard thing to deal with. I went through the same thing with my 20 year old feline assistant in June. Beer helps. Fresh beer, that is. Fresh saves on cleaning up the mouth spray afterwards. All things in moderation. Including moderation itself. I need to adopt a couple new family members, but kittens plus christmas tree equals trouble. Darned cute when they curl up asleep among the scattered ornaments underneath it, though.
===============
Getting a little less unsteamly: I am very conscious of the effects of running with a cold engine, when choosing engine valve system & control features. With cold metal sucking heat/pressure out of the steam, residual exhaust recompression will be lower for a given inlet pressure, compared to hot-engine results, for one thing. With ultralow clearance volume and low exhaust release pressures (idling?), warmup condensate may cause problems too. I have wondered whether a well-insulated engine cools more/faster when idling at low pressure than when coasting to a stop and sitting -- and engines do warm up faster under load (doing work in the process) than when idling.
On the Williams engine, they did claim 30 mpg from their roadster, but I wonder what percentage of road time was devoted to running in "rankine mode", with the auxiliary exhaust and late cutoff. A Williams-like engine _might_ have a shot at higher actual efficiency in highway cruising, if the engine is carefully sized for the vehicle. Big engine for hi HP, plus "it's Williams so its efficient", I'm not sure. There are often big differences in mpg/efficiency with different-sized IC engines in the same car; I don't think that "an" engine has "an" efficiency.
And often efficiently-sized/designed engines don't sell -- or in our case aren't pleasing to the efficiency-minded hobbyists who built them -- due to lower performance. Cost is a factor too. My Bug costs a fraction as much per mile, overall, as far more fuel-efficient cars, due to the cheap and primitive tech on board. Even when fuel prices were spiking toward traditionally European levels earlier this year. Anyway, these are a few of the things I've been pondering and looking out for.
I got my new Bulletin yesterday, and noticed that Peter Pellandine has finally found a good grind for his cams for smooth and quiet running. Wanted to mention this to update my previous remarks in another thread.
Jim, I have looked into shifting eccentrics. These can be simpler than linkage valve gears, one less eccentric per valve sure would be nice, but it takes more development work (design, build, test, redesign, rebuild, retest, etc) to get the actuation and timing right with any experimental valve gear (even if it a proven type), than just brazenly plagiarizing Stephenson geometry from Stanley blueprints. Also, I have read that many professional outfits ran into long-term durability issues with shifting eccentrics in locomotives. For an amateur designer/builder like me, the odds of durability and timing/actuation problems with an experimental valve gear design look lots higher than for the pros. In my case, with this first-build project, I prefer the extra machine work (already planned out for my machine tools) to get as close as I can to a road-tested design, sooner.
If/when I get everything else running, I can get more experimental, including other valve gear and valve types, for accurate "all else being equal" comparisons. My engine design is modular, and looks very conducive to experimental changes. Even the piston-to-slide valve change in May, only took me a week or two from raw concept to strength-analyzed, fully-dimensioned, and machining-planned shop drawings.
Peter
Edited 2 time(s). Last edit at 11/30/2008 03:00AM by Peter Brow.
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Re: Williams ws. Rankin November 30, 2008 03:13AM |
Registered: 19 years ago Posts: 657 |
Me thinks that a reason for the auxilary exhaust in the Williams design was to counter the "automatic" reversing issue that Doble encountered with his engine. It seems to me that the most successfull unaflow engines were the ones that never stoped running and ran fast as compared to the Stanley etc.
Coburn once mentioned issues with Unaflow tractors reversing under a heavy starting load and well, doing bad things to people around them.
From a passanger seat whitness account of riding with one of the Williams car, the guy said that when starting he ran the auxilary working and once up to about 15 to 30 or so went to unaflow, although unaflow is a bit ambigous if one wants to get technical, since the auxilary exhaust valves only exhaust anyways, but that would make a Corlis a unaflow engine, well, OK. lets not get technical now.LOL
From a SAE transactions paper that I just read(some of) Scott from Scott/Newcomb stated that their engine used from 12 to 15 lbs of steam per hp hr, this from a semi unaflow, not that diferent from a good White engine or Doble or for that matter a tip top Stanley engine(I have read 15 lbs water rate when fitted up well and with good tight valves).
Finding things like this is making me care less and less about which engine design is better then which, when the biggest difference is only 20% or so, except for the Williams engine which has been credited with 5 to 6 lbs of steam per hp hr, although there is a bit of confusion as to what are the real numbers when those engines are concerned, I have never heard of a test when the brothers were not around to supervise. I am not a French man throwing his saboes into the gears of a snow mover(the origin of sabotour), just asking what is what with the Williams, what is real and what is hype and what is fake.
Caleb Ramsby
Coburn once mentioned issues with Unaflow tractors reversing under a heavy starting load and well, doing bad things to people around them.
From a passanger seat whitness account of riding with one of the Williams car, the guy said that when starting he ran the auxilary working and once up to about 15 to 30 or so went to unaflow, although unaflow is a bit ambigous if one wants to get technical, since the auxilary exhaust valves only exhaust anyways, but that would make a Corlis a unaflow engine, well, OK. lets not get technical now.LOL
From a SAE transactions paper that I just read(some of) Scott from Scott/Newcomb stated that their engine used from 12 to 15 lbs of steam per hp hr, this from a semi unaflow, not that diferent from a good White engine or Doble or for that matter a tip top Stanley engine(I have read 15 lbs water rate when fitted up well and with good tight valves).
Finding things like this is making me care less and less about which engine design is better then which, when the biggest difference is only 20% or so, except for the Williams engine which has been credited with 5 to 6 lbs of steam per hp hr, although there is a bit of confusion as to what are the real numbers when those engines are concerned, I have never heard of a test when the brothers were not around to supervise. I am not a French man throwing his saboes into the gears of a snow mover(the origin of sabotour), just asking what is what with the Williams, what is real and what is hype and what is fake.
Caleb Ramsby
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Re: Williams ws. Rankin November 30, 2008 08:04AM |
Registered: 19 years ago Posts: 1,771 |
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Re: Williams ws. Rankin November 30, 2008 02:14PM |
Registered: 19 years ago Posts: 1,453 |
Hi Caleb,
The best Stanley water rates I have read of (so far) were 16-17 lbs/hp/hr, in Stanley factory tests of new Model 735 (20 hp/4x5) engines. Source: The Journal of the Society of Automotive Engineers, May, 1918, page 17, reprinted in the Stanley Dealer Bulletins volume from the Stanley Museum:
"A stock engine under test-block run has frequently operated with a steam consumption of 16 to 17 lb. per hp-hr., a remarkable result from so small an engine."
My guess is that these results were obtained at rpms equivalent to somewhat higher road speeds, hooked up/early cutoff, and probably at simulated road loads. In similar steady-state test conditions, a halfway decent poppet-valved unaflow could easily shave 1-2 lbs per hp/hr off of those figures. Whether such an engine would be better overall through a whole drive cycle under actual road conditions is a different matter.
Later in the same article:
"As the engine is a relatively minor problem in steam cars -- owing to steam engine practice being so highly standardized -- differences in type or details of construction are not of such pronounced moment as the major problems of burner and boiler. Another company (now among the gas-car manufacturers) [White -- peb] for a few years used a compound engine. The unaflow type has been proposed and much discussed recently [Doble-Detroit? -- peb]. We conducted tests on a unaflow engine a year ago and failed to discover any superior steam economy. We did encounter many minor disadvantages in this type when applied to automobiles, among which were uncertainty at times as to whether the car would run forward or backward on starting, and the possibility that it would not start at all. Furthermore, its high compression was a disadvantage and its weight and size exceeded that of the contraflow type.
"These difficulties could be overcome in considerable measure, but so doing would modify the unaflow type to the point that its characteristic feature would be largely lost, and there would be added complications in construction.
"The use of high superheat, moreover, largely minimizes the benefit of the unaflow cycle, and the absence of vacuum futher defeats its primary advantage."
The title of the article is "The Case for the Steam Car", by John Sturgess of the Stanley Motor Carriage Company. Hardly an impartial independent perpective, but then again not a "we won't even consider different engines because FE & FO were always right" point of view either.
I wonder what type of unaflow engine the Stanley Co. tested? Did they somehow wangle a Doble-Detroit engine for testing? Have any other records of these tests survived? Sturgess' comment on vacuum condensing mirrors what Ken, Bill, and others have said recently.
Another quote from the above article which should be of interest to everyone here:
"We will not undertake to conjecture what the steam car would be today if abler minds than ours, the minds that have combated [sic] the difficulties of the internal-explosive engine, had applied themselves to this inherently simpler problem."
The article concludes with a bit more gusto:
"The time has come, we believe, when the industry must give pause to consider seriously our assertion that steam is not only the shortest but indeed the only route to automobile perfection."
Apparently that time had not, in fact, come yet in 1918, and it still hasn't, 90 years later.
Peter
The best Stanley water rates I have read of (so far) were 16-17 lbs/hp/hr, in Stanley factory tests of new Model 735 (20 hp/4x5) engines. Source: The Journal of the Society of Automotive Engineers, May, 1918, page 17, reprinted in the Stanley Dealer Bulletins volume from the Stanley Museum:
"A stock engine under test-block run has frequently operated with a steam consumption of 16 to 17 lb. per hp-hr., a remarkable result from so small an engine."
My guess is that these results were obtained at rpms equivalent to somewhat higher road speeds, hooked up/early cutoff, and probably at simulated road loads. In similar steady-state test conditions, a halfway decent poppet-valved unaflow could easily shave 1-2 lbs per hp/hr off of those figures. Whether such an engine would be better overall through a whole drive cycle under actual road conditions is a different matter.
Later in the same article:
"As the engine is a relatively minor problem in steam cars -- owing to steam engine practice being so highly standardized -- differences in type or details of construction are not of such pronounced moment as the major problems of burner and boiler. Another company (now among the gas-car manufacturers) [White -- peb] for a few years used a compound engine. The unaflow type has been proposed and much discussed recently [Doble-Detroit? -- peb]. We conducted tests on a unaflow engine a year ago and failed to discover any superior steam economy. We did encounter many minor disadvantages in this type when applied to automobiles, among which were uncertainty at times as to whether the car would run forward or backward on starting, and the possibility that it would not start at all. Furthermore, its high compression was a disadvantage and its weight and size exceeded that of the contraflow type.
"These difficulties could be overcome in considerable measure, but so doing would modify the unaflow type to the point that its characteristic feature would be largely lost, and there would be added complications in construction.
"The use of high superheat, moreover, largely minimizes the benefit of the unaflow cycle, and the absence of vacuum futher defeats its primary advantage."
The title of the article is "The Case for the Steam Car", by John Sturgess of the Stanley Motor Carriage Company. Hardly an impartial independent perpective, but then again not a "we won't even consider different engines because FE & FO were always right" point of view either.
I wonder what type of unaflow engine the Stanley Co. tested? Did they somehow wangle a Doble-Detroit engine for testing? Have any other records of these tests survived? Sturgess' comment on vacuum condensing mirrors what Ken, Bill, and others have said recently.
Another quote from the above article which should be of interest to everyone here:
"We will not undertake to conjecture what the steam car would be today if abler minds than ours, the minds that have combated [sic] the difficulties of the internal-explosive engine, had applied themselves to this inherently simpler problem."
The article concludes with a bit more gusto:
"The time has come, we believe, when the industry must give pause to consider seriously our assertion that steam is not only the shortest but indeed the only route to automobile perfection."
Apparently that time had not, in fact, come yet in 1918, and it still hasn't, 90 years later.
Peter
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Re: Williams ws. Rankin November 30, 2008 03:06PM |
Admin Registered: 18 years ago Posts: 2,107 |
I really doubt contiuously variable sliding camshafts are all that practical in real world applications. "Normal" camshafts have the same profile across the whole face and therefor a large contact area. The continuously variable camshaft has a point contact and that is just looking for rapid wear.
Sliding camshafts with a variety of distinct profiles should hold up just fine, the wear is now across the full face.
Like everything else to do with steam, you have to make fine distinctions else end up wrong at least a fair part of the time.
Regards,
Ken
Sliding camshafts with a variety of distinct profiles should hold up just fine, the wear is now across the full face.
Like everything else to do with steam, you have to make fine distinctions else end up wrong at least a fair part of the time.
Regards,
Ken
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Re: Williams ws. Rankin November 30, 2008 04:29PM |
Registered: 19 years ago Posts: 657 |
Peter,
I think that the unaflow test refered to in the SAE journal might be the one that I posted a while back on my MIT papers thread.
[www.steamautomobile.com]
The one by Mr. Proctor done in June, 1917. He tested a Stumpf unaflow engine and recorded 21 to 30 some lbs of steam per hp hr. However, the report seems to be a bit incomplete as there is no definition of the testing aparatus, engine cutoffs etc. Although there is a record of exhaust pressure, inlet pressure superheat, etc.
The gearing of the car is about 600 revs per mile or so, pretty long legs!
In the 1904 test, 21 to 40 lbs per hp hr, with a new 2 1/2" by 3 1/2" engine, best rate is at 1/5 cutoff, 600 deg steam, 545 rpm, around 5 hp. This was with a boiler effeciency of 60%, pushing it hard.
I remember seeing 15 lbs per hp hr for a Stanley engine somewhere, this however may be a false memory, it's hard to tell sometimes.
HEY, has anybody come across an test data from the Bryan tractor engine, with it's big ol piston valves?
Caleb Ramsby
I think that the unaflow test refered to in the SAE journal might be the one that I posted a while back on my MIT papers thread.
[www.steamautomobile.com]
The one by Mr. Proctor done in June, 1917. He tested a Stumpf unaflow engine and recorded 21 to 30 some lbs of steam per hp hr. However, the report seems to be a bit incomplete as there is no definition of the testing aparatus, engine cutoffs etc. Although there is a record of exhaust pressure, inlet pressure superheat, etc.
The gearing of the car is about 600 revs per mile or so, pretty long legs!
In the 1904 test, 21 to 40 lbs per hp hr, with a new 2 1/2" by 3 1/2" engine, best rate is at 1/5 cutoff, 600 deg steam, 545 rpm, around 5 hp. This was with a boiler effeciency of 60%, pushing it hard.
I remember seeing 15 lbs per hp hr for a Stanley engine somewhere, this however may be a false memory, it's hard to tell sometimes.
HEY, has anybody come across an test data from the Bryan tractor engine, with it's big ol piston valves?
Caleb Ramsby
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Re: Williams ws. Rankin November 30, 2008 06:32PM |
Registered: 19 years ago Posts: 1,519 |
Considering thing's,
I thought That I would add these three 'links or pictures'. I would like to say that Ive since communicated with Andy so there is some data thats being withheld, although is currently available here on the phorum if that you can find it.
[www.steamautomobile.com]
[www.steamautomobile.com]
[www.steamautomobile.com]
I distinctly rememebering a comment about 'hey- nice ring's' but cant seem to find it just now.
Best
Jeremy
I thought That I would add these three 'links or pictures'. I would like to say that Ive since communicated with Andy so there is some data thats being withheld, although is currently available here on the phorum if that you can find it.
[www.steamautomobile.com]
[www.steamautomobile.com]
[www.steamautomobile.com]
I distinctly rememebering a comment about 'hey- nice ring's' but cant seem to find it just now.
Best
Jeremy
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