Saturday, November 28, 2009
Friday, September 04, 2009
Sunday, August 23, 2009
Thursday, August 13, 2009
Quote of the unspecified temporal interval
Those who listened unwarily to that voice could seldom report the words that they heard. . . . Mostly they remembered only that it was a delight to hear the voice speaking, all that it said seemed wise and reasonable."
-J. R. R. Tolkien
LOTR The Two Towers
Why is it I think of this quote now whenever I see a politician giving a speech that warrants TV air-time?
Tuesday, August 11, 2009
Sunday, August 09, 2009
Safety First
Sunday, August 02, 2009
Daylight on a cloudy day
A couple weeks back people throughout the upper Midwest were treated to an unusual sight. Southern Pacific engine 4449 came through Chicago as part of a much longer excursion trip.
Engines like this were built fairly late into the steam era and as far as I’m concerned, they are at or near the pinnacle of American passenger locomotive design. The semi-streamlined look came into vogue after diesel engines had made their big debut in the rail passenger industry. Of course there were some bizarre overreactions by designers that turned lovely steamers into streamlined, if oddly proportioned, chunks of stainless steel. Unlike the retrofitted giants like “Big Alice the Goon” (which is a topic for a post unto itself) this locomotive has enough shrouds and curves to maintain a graceful appearance while still showing enough hardware to make it clear that she’s a no nonsense western locomotive.
The day the train rolled through it was clear that the word was already out long before the big spectacle. Dozens of people lined up on each platform along the BNSF line with cameras on tripods, video cameras and railroad scanners. I met some friends at a station just West of Lagrange where we thought the crowd might be a little thinner. It wasn’t too bad it was still difficult to find some place where your photo would be relatively undisturbed by your fellow train watchers.
The scanners called out the stations as the train passed. We knew it couldn’t be long when we heard a strangely un-diesel-like grade crossing whistle in the distance. We all assumed out positions, meaning we probably all looked like a bunch of idiots ducking and swerving our heads to frame the best view.
The light was surprisingly close to our position when it first appeared. I snapped my first glimpse of the engine.
Then another as it came into full view.
Once more in the center of the frame
And then several seconds of blurred cars, some in Daylight limited red and orange, some in silver, Pullman green and eventually a Hiawatha orange observation car.
At this point I think railfan D (the guy on the left) is laughing at railfan Dave who was apparently blown over from his somewhat awkward perch. The train was traveling at near 50 mph so it made quite a commotion.
And then it was quiet again with only a lingering haze over the tracks to remind us of what had just happened. Seventy years ago nobody would have thought twice such a sight. Now that it’s rare we can see how beautiful a sight it really is.
Sunday, July 19, 2009
Ooh, look, I have a blog!
If you're still checking my blog, you are either a very loyal follower or you are really in need of some entertainment.
For the last few months I've been holed up in various hotel rooms and offices in between visits with real estate agents. I really haven't had the energy to put up any new material. I do have some articles in the pipeline but they won't be ready until I have a few calm days to work out my thoughts.
For now at least, I'll be loading up some simple posts to be posted automatically, then I'll probably start writing again next month.
In the mean time, there is some excellent reading material in the blogs listed to the right. Enjoy!
Thursday, April 16, 2009
mmmm, bacon!
It's not just for breakfast anymore!
I recently ran across this over at make blog. You'd have to be borderline insane to think of this, but I have to admit it's cool.
The Flaming Bacon Lance of Death
Basically it's a bacon powered torch. It sounds nuts, but it's essentially a lot of oxygen being forced through an oily substance so that it burns very quickly. I bet that with the O2 hooked up you could burn up all of the bacon grease in nothing flat.
Who wants it crispy?!
I recently ran across this over at make blog. You'd have to be borderline insane to think of this, but I have to admit it's cool.
The Flaming Bacon Lance of Death
Basically it's a bacon powered torch. It sounds nuts, but it's essentially a lot of oxygen being forced through an oily substance so that it burns very quickly. I bet that with the O2 hooked up you could burn up all of the bacon grease in nothing flat.
Who wants it crispy?!
Wednesday, April 15, 2009
Sunday, April 12, 2009
Friday, April 10, 2009
Tuesday, April 07, 2009
A little church in Tennessee
About this time 147 years ago thousands of weary soldiers near Pittsburg Landing on the Tennessee River saw the close of the second day of the battle of Shiloh.
The battle began on the morning of April 6 with a Confederate attack led by General Johnston’s army. A night of quietly waiting just a few miles to the south of the Union camp paid off as the Union encampment was nearly taken by surprise. Union troops fell back quickly in the early morning hours as they struggled to form cohesive lines of battle. A few rallies, combined with a somewhat uncoordinated confederate attack eventually slowed the advance enough for the Union troops to establish defensive lines around what was known as the Hornet’s nest.
I had the chance to visit this battlefield a few weeks back. It was a dull, and appropriately somber day to visit a battlefield, but still pleasant enough to spend some time walking along the sunken road in front of the hornet’s nest.
I began at Ruggles’ batteries, on the western side of the Confederate lines. From here, the Confederate artillery bombarded the Union lines from acrossDuncan field during the afternoon of the 6th. All the while, the Union troops also endured frontal assaults and flanking fire.
Crossing the field I began to walk down the sunken road, which marks the Union line for most of the day of April 6. This area received massive amounts of fire throughout the day, only falling into Confederate hands late in the afternoon.
Standing here, it's amazing to think about the amount of fire taken by the soldiers in this position, and perhaps it is equally amazing to think of Confederate troops staging attacks across this open field.
I continued on to the east, following the Union line. Eventually it proceeds into more wooded areas.
In these areas a few seemingly abandoned monuments rise up along the path, marking the positions held throughout the day.
Eventually the Union line emerges into an open area where an orchard once grew. Soldiers reportedly said that the bullets clipped so many blossoms from the trees that it looked like falling snow. The orchard has recently been replanted, and in another decade it may start to look much more like it did during the battle.
Only a little further north is the site ofShiloh ’s bloody pond, where wounded soldiers nursed their wounds until the ponds waters turned red.
It’s a serene scene now, but in 1962 this would have been a chaotic place with wounded soldiers and abandoned equipment all around the pond. It’s hard to believe this was once such a dismal place.
On this end of the line, the Union troops could have easily lost the battle. Had Confederate troops exploited a collapse in the Union lines, they could have forced them away from Pittsburg Landing, which could have ultimately led to a Confederate victory. Confusion in the Confederate ranks kept them from exploiting the Union weaknesses, due at least in part to the loss of General Johnston who was wounded in battle, and bled out, not knowing the seriousness of his wound.
Eventually the Union lines fell back, forming a line around Pittsburg Landing. In the evening hours, reinforcements were ferried across the river to join Grant’s troops. Come the morning hours the Union counterattack began and Confederate general Beauregard suddenly found himself outnumbered and outgunned. A hard day of battle followed in which the Confederate forces were pushed back South, eventually retreating toward Corinth, leaving only a field hospital and a rear guard.
It was a horrifically bloody battle that would grab the attention of the nation. It was reported as the battle ofShiloh because of the small church by this name that stood in the middle of the battlefield. Ironically enough this name means “place of peace.” There is still a church here today that holds regular services, and there is a smaller log structure that has been constructed here as a reminder of the church that stood here during the 1860s.
The battle began on the morning of April 6 with a Confederate attack led by General Johnston’s army. A night of quietly waiting just a few miles to the south of the Union camp paid off as the Union encampment was nearly taken by surprise. Union troops fell back quickly in the early morning hours as they struggled to form cohesive lines of battle. A few rallies, combined with a somewhat uncoordinated confederate attack eventually slowed the advance enough for the Union troops to establish defensive lines around what was known as the Hornet’s nest.
I had the chance to visit this battlefield a few weeks back. It was a dull, and appropriately somber day to visit a battlefield, but still pleasant enough to spend some time walking along the sunken road in front of the hornet’s nest.
Click Here [+/-]
I began at Ruggles’ batteries, on the western side of the Confederate lines. From here, the Confederate artillery bombarded the Union lines from across
Crossing the field I began to walk down the sunken road, which marks the Union line for most of the day of April 6. This area received massive amounts of fire throughout the day, only falling into Confederate hands late in the afternoon.
Standing here, it's amazing to think about the amount of fire taken by the soldiers in this position, and perhaps it is equally amazing to think of Confederate troops staging attacks across this open field.
I continued on to the east, following the Union line. Eventually it proceeds into more wooded areas.
In these areas a few seemingly abandoned monuments rise up along the path, marking the positions held throughout the day.
Eventually the Union line emerges into an open area where an orchard once grew. Soldiers reportedly said that the bullets clipped so many blossoms from the trees that it looked like falling snow. The orchard has recently been replanted, and in another decade it may start to look much more like it did during the battle.
Only a little further north is the site of
It’s a serene scene now, but in 1962 this would have been a chaotic place with wounded soldiers and abandoned equipment all around the pond. It’s hard to believe this was once such a dismal place.
On this end of the line, the Union troops could have easily lost the battle. Had Confederate troops exploited a collapse in the Union lines, they could have forced them away from Pittsburg Landing, which could have ultimately led to a Confederate victory. Confusion in the Confederate ranks kept them from exploiting the Union weaknesses, due at least in part to the loss of General Johnston who was wounded in battle, and bled out, not knowing the seriousness of his wound.
Eventually the Union lines fell back, forming a line around Pittsburg Landing. In the evening hours, reinforcements were ferried across the river to join Grant’s troops. Come the morning hours the Union counterattack began and Confederate general Beauregard suddenly found himself outnumbered and outgunned. A hard day of battle followed in which the Confederate forces were pushed back South, eventually retreating toward Corinth, leaving only a field hospital and a rear guard.
It was a horrifically bloody battle that would grab the attention of the nation. It was reported as the battle of
Click here to close.
Monday, April 06, 2009
Wednesday, April 01, 2009
Don't be fooled!
Today I have a word of warning for my fellow travellers. If you happen to be using the toiletries provided by your hotel, don't just assume that the pale blue liquid is going to be mouthwash.
You might be in for a nasty surprise if you try to gargle this. Luckily I didn't learn this lesson first hand, but a coworker who shall remain nameless had the unpleasant experience of having his mouth washed out with soap before he began cursing.
Wednesday, March 25, 2009
Come out to Como
If you happen to be in the Memphis and have some unsatisfied carniverous tendencies, drive south to the town of Como Mississippi. It's not a very big town by any measure and most travellers wouldn't have a reason to take the Como exit off of I 55. But for those who know about the Como Steakhouse, it's well worth the trip to eat here.
They have some great aged beef here, and if you walk away from a meal hungry, it's nobody's fault but your own. I'm also told they serve great fried olives (don't laugh, this is Mississippi, it's the way food is prepared here) that are stuffed with pepper jack cheese. And for dessert you can enjoy a nice piece of bourbon pecan pie. Of course, I've never tried the olives or the pie. Not only am I unable to eat another bite after even one of their small cuts of meat, but I'm not entirely certain that I can handle two new forms of vice in my life.
They have some great aged beef here, and if you walk away from a meal hungry, it's nobody's fault but your own. I'm also told they serve great fried olives (don't laugh, this is Mississippi, it's the way food is prepared here) that are stuffed with pepper jack cheese. And for dessert you can enjoy a nice piece of bourbon pecan pie. Of course, I've never tried the olives or the pie. Not only am I unable to eat another bite after even one of their small cuts of meat, but I'm not entirely certain that I can handle two new forms of vice in my life.
Monday, March 09, 2009
Or would you rather be an engineer?
I should really start turning the light out when I leave for a while.
For the last month or so I've been pretty much covered with work and I've been bouncing back and forth between Chicago and Batesville MS. All of this work has made me wonder though, how many other people would be willing to do this kind of job? Does anyone else like long lines in airports, late nights working in strange factories, panicked phone calls about broken machines in far away places?
OK, I don't either. Still, you might find that you have the right mindset to make it as an engineer on the road. Just test yourself in these scenarios and see how you do.
You have just finished packing your suitcase. You are scheduled to fly out early in the morning on the red-eye flight. Just as your head hits the pillow the power blinks out for about two seconds. You know that you'll need an alarm to get up in time to make your flight.
Do you:
A. Reset the alarm clock and hope the power doesn't go off again
B. Call a trusted friend (or wake-up call service) to insure that you'll be woken up on time.
C. Stay up all night making sure the power doesn't go off again
D. Roll over and go to sleep because your cell phone and digital watch will wake you up anyway
The correct answer is D. There should be at least one battery powered digital device around that makes noise or else you obviously don't have an engineer's passion for gadgets.
You wake up on time and drive to the airport in the dark. As you park you reach for the headlight switch but the knob falls off in your hand. You can grasp the end of the stub to which the knob was attached, but you can't grip it well enough to turn it.
Do you:
A: Leave your lights on and hope you can get a jump start when you come back.
B: Call your friend (the only one you know is awake because he already woke you up in question one) and see if he has any advice.
C: Pop the hood and disconnect the battery.
D: Grab the vice grips you keep under the passenger seat and use them to turn off the headlights.
The best answer here is D because you should have tools handy at all times (no self respecting engineer would be caught without vice grips unless airport security confiscated them.) Partial credit will be awarded for anyone who answers C as this should solve the problem. It's just too much work to be the best answer.
You check your bags and have plenty of time to spare because you answered D on the last question. What do you do with your spare time?
A: Get an overpriced coffee and scone at one of the Coffee Kiosks in the airport.
B: Find a seat and enjoy some people watching while you wait for your flight.
C: Get out your laptop and search for free WiFi in the terminal
D: Go through the metal detector multiple times with progressively increasing numbers of coins in your pockets to see how much it takes to set it off.
C is the most likely answer here, as being offline for too long can lead to email withdrawal. A has one redeeming feature in that it involves coffee, but that doesn't offset the fact that it is overpriced and way too trendy. Answer D is worth bonus points because it demonstrates curiosity and creativity in testing an otherwise annoying device. If you wrote in "Spend some time trying to figure out why the banners in the tram station saying 'We're glad you're here!' are facing the people who are leaving town," then you have potential but you might be headed for something a little more philosophical in nature
You arrive at your destination and spend a very long day working on all manner or technical problems. When you finally finish it is almost 2 AM. You are hungry but cannot find any 24 hour diners on the way back to your hotel. You do, however, have a pack of ramen noodles from a convenience store. Your hotel room has no microwave, bowls, spoons, or forks. What do you do?
A: Go to bed hungry.
B: Alternate bites of dry ramen with swigs of water. Try to ignore your bleeding gums.
C: crush the noodles into a water cup and try soaking the noodles in luke warm tap water. Eat them quickly enough and you won't care that it tastes lousy.
D: Use the coffee maker in your room to heat water, soak the noodles in the carafe, and use the plastic coffee stirrers for chopsticks.
If you have to ask which one it is, you should stop reading right now. I have actually made ramen in a coffee maker, and when you're hungry at 2AM, it tastes really good!
You finish your work the next day, fill out an exit report and gather your bags for the trip to the airport. Just as you are ready to walk out the door a supervisor shows up with a piece of equipment he wants you to take home with you. You inspect the equipment and it shouldn't be a security risk as long as it's in checked luggage, but you only packed a small suitcase for this trip, so there's no way this thing is going to fit in your luggage. Your accountants have told you to avoid the extra bag charges, and you don't have the option of carrying this thing onto the airplane.
Do you:
A: Tell the supervisor just to ship it himself.
B: Try to sneak out of the plant before the supervisor notices.
C: Pay the extra luggage fee and fight it out with accounting later.
D: Find a box that's big enough to hold the equipment and your luggage so that you only have to check one item at the airport.
Once again the answer is D. I've had to do this at the last minute before leaving. Once I even got to the airport and scrounged an extra box and tape from the rental car office!
You catch your flight, collect your luggage and head to the parking lot. Arriving back at your car you remember the problem with the headlight switch. You take a moment to consult the repair manual (which you have conveniently tucked into the compartment next to the jack and tire tool.) According to the manual you will need to take apart half of the dashboard to reach the back of the switch and fasten it back in place.
Do you:
A: Take the car to a garage so a mechanic can disassemble your dashboard and repair the switch.
B: Continue to use the vice grips indefinitely.
c: Take apart the dashboard yourself and repair the switch
D: Ignore the manual and find your own way to reach the switch that only takes 10 minutes rather than 10 hours.
It's a bit of a stretch to assume that anyone reads the manual first, but as far as I'm concerned it doesn't matter because the correct answer is D: Ignore the manual. And as for answers B and C, well one is too simple and the other is too much work.
So how did you do? Let me know if you came up with the right answers on every question because I need some extra help!
For the last month or so I've been pretty much covered with work and I've been bouncing back and forth between Chicago and Batesville MS. All of this work has made me wonder though, how many other people would be willing to do this kind of job? Does anyone else like long lines in airports, late nights working in strange factories, panicked phone calls about broken machines in far away places?
OK, I don't either. Still, you might find that you have the right mindset to make it as an engineer on the road. Just test yourself in these scenarios and see how you do.
Click Here [+/-]
You have just finished packing your suitcase. You are scheduled to fly out early in the morning on the red-eye flight. Just as your head hits the pillow the power blinks out for about two seconds. You know that you'll need an alarm to get up in time to make your flight.
Do you:
A. Reset the alarm clock and hope the power doesn't go off again
B. Call a trusted friend (or wake-up call service) to insure that you'll be woken up on time.
C. Stay up all night making sure the power doesn't go off again
D. Roll over and go to sleep because your cell phone and digital watch will wake you up anyway
The correct answer is D. There should be at least one battery powered digital device around that makes noise or else you obviously don't have an engineer's passion for gadgets.
You wake up on time and drive to the airport in the dark. As you park you reach for the headlight switch but the knob falls off in your hand. You can grasp the end of the stub to which the knob was attached, but you can't grip it well enough to turn it.
Do you:
A: Leave your lights on and hope you can get a jump start when you come back.
B: Call your friend (the only one you know is awake because he already woke you up in question one) and see if he has any advice.
C: Pop the hood and disconnect the battery.
D: Grab the vice grips you keep under the passenger seat and use them to turn off the headlights.
The best answer here is D because you should have tools handy at all times (no self respecting engineer would be caught without vice grips unless airport security confiscated them.) Partial credit will be awarded for anyone who answers C as this should solve the problem. It's just too much work to be the best answer.
You check your bags and have plenty of time to spare because you answered D on the last question. What do you do with your spare time?
A: Get an overpriced coffee and scone at one of the Coffee Kiosks in the airport.
B: Find a seat and enjoy some people watching while you wait for your flight.
C: Get out your laptop and search for free WiFi in the terminal
D: Go through the metal detector multiple times with progressively increasing numbers of coins in your pockets to see how much it takes to set it off.
C is the most likely answer here, as being offline for too long can lead to email withdrawal. A has one redeeming feature in that it involves coffee, but that doesn't offset the fact that it is overpriced and way too trendy. Answer D is worth bonus points because it demonstrates curiosity and creativity in testing an otherwise annoying device. If you wrote in "Spend some time trying to figure out why the banners in the tram station saying 'We're glad you're here!' are facing the people who are leaving town," then you have potential but you might be headed for something a little more philosophical in nature
You arrive at your destination and spend a very long day working on all manner or technical problems. When you finally finish it is almost 2 AM. You are hungry but cannot find any 24 hour diners on the way back to your hotel. You do, however, have a pack of ramen noodles from a convenience store. Your hotel room has no microwave, bowls, spoons, or forks. What do you do?
A: Go to bed hungry.
B: Alternate bites of dry ramen with swigs of water. Try to ignore your bleeding gums.
C: crush the noodles into a water cup and try soaking the noodles in luke warm tap water. Eat them quickly enough and you won't care that it tastes lousy.
D: Use the coffee maker in your room to heat water, soak the noodles in the carafe, and use the plastic coffee stirrers for chopsticks.
If you have to ask which one it is, you should stop reading right now. I have actually made ramen in a coffee maker, and when you're hungry at 2AM, it tastes really good!
You finish your work the next day, fill out an exit report and gather your bags for the trip to the airport. Just as you are ready to walk out the door a supervisor shows up with a piece of equipment he wants you to take home with you. You inspect the equipment and it shouldn't be a security risk as long as it's in checked luggage, but you only packed a small suitcase for this trip, so there's no way this thing is going to fit in your luggage. Your accountants have told you to avoid the extra bag charges, and you don't have the option of carrying this thing onto the airplane.
Do you:
A: Tell the supervisor just to ship it himself.
B: Try to sneak out of the plant before the supervisor notices.
C: Pay the extra luggage fee and fight it out with accounting later.
D: Find a box that's big enough to hold the equipment and your luggage so that you only have to check one item at the airport.
Once again the answer is D. I've had to do this at the last minute before leaving. Once I even got to the airport and scrounged an extra box and tape from the rental car office!
You catch your flight, collect your luggage and head to the parking lot. Arriving back at your car you remember the problem with the headlight switch. You take a moment to consult the repair manual (which you have conveniently tucked into the compartment next to the jack and tire tool.) According to the manual you will need to take apart half of the dashboard to reach the back of the switch and fasten it back in place.
Do you:
A: Take the car to a garage so a mechanic can disassemble your dashboard and repair the switch.
B: Continue to use the vice grips indefinitely.
c: Take apart the dashboard yourself and repair the switch
D: Ignore the manual and find your own way to reach the switch that only takes 10 minutes rather than 10 hours.
It's a bit of a stretch to assume that anyone reads the manual first, but as far as I'm concerned it doesn't matter because the correct answer is D: Ignore the manual. And as for answers B and C, well one is too simple and the other is too much work.
So how did you do? Let me know if you came up with the right answers on every question because I need some extra help!
Click here to close.
Monday, February 02, 2009
Quote of the unspecified temporal interval
Coffee is a beverage that puts one to sleep when not drank.Alphonse Allais
Monday, January 26, 2009
Public Service Announcment
True Blue Sam forwarded this site to me because I'm in Mankato MN right now.
Apparently I'm in a 'hidden tourist mecca' with some neighborhoods that never drop below 70 degrees F.
I don't know where those neighborhoods are or I would be staying there.
The view from where I'm working is somewhat more bleak.
Oh and it was a brisk 5F when this picture was taken. Where are those 70 degree neighborhoods?!
Apparently I'm in a 'hidden tourist mecca' with some neighborhoods that never drop below 70 degrees F.
I don't know where those neighborhoods are or I would be staying there.
The view from where I'm working is somewhat more bleak.
Oh and it was a brisk 5F when this picture was taken. Where are those 70 degree neighborhoods?!
Saturday, January 17, 2009
Nothing up my sleeve valve
I think I might be approaching steam engine overload after the last few posts, so it's time to focus on some internal combustion technology instead.
If you've ever heard of a Willys Knight then you probably know it has a somewhat unusual engine.
While most automobile engines use a poppet valve system, the knight was known for having a sleeve valve system instead. Now if you're reading this page, there's a better than average chance that you know the difference between a sleeve valve and a poppet valve, but just in case let's do a little review.
Your typical auto engine runs on a 4 stroke system, where every two rotations of the crankshaft can be divided into 4 main phases: intake, compression, power, and exhaust. During the intake and the exhaust strokes it is necessary to open valves for fuel and air intake and venting the exhaust gases. A poppet valve is usually positioned in an arrangement something like this.
Taken from Audels New Automobile Guide
A spring holds the valve shut while a cam actuates the valve during the brief period that it needs to be opened. Different valves are actuated by different cams so timing the valves is fairly straightforward.
A sleeve valve system looks more like this.
Rather than having two or more valves in the top of a cylinder there are two sleeves inside the cylinder and around the piston. The sleeves are controlled by connecting rods, linked to a small crankshaft which takes the place of the poppet valve's camshaft.
Interestingly enough, the sleeve valve system seems to have more in common with a steam engine than an internal combustion engine. Early steam engines had slide valves that controlled steam inlets and exhaust, but these sleeve valves are much more advanced than most steam chest slide valves in both timing and design. A common problem with slide valves was 'cutting' of the sliding surfaces due to force from the steam pressure in the cylinder, but a sleeve valve that wraps around the cylinder has pressure on all sides and so there is virtually no unbalanced force to cause cutting of the valve surfaces.
Each sleeve has two ports in it on opposite sides. One port is for exhaust, one is for the intake.
On the intake stroke, the left hand ports align creating an opening for fuel and air to be drawn into the cylinder. As the piston passes bottom dead center, the ports in the sleeve pass the intake passage sealing the opening. The piston continues upward compressing the fuel air mixture in the now sealed cylinder.
Near the top of the stroke, the fuel air mixture is ignited by the spark plug. The sleeves travel downward but stay just far enough out of alignment to avoid opening the exhaust or the inlet port.
Taken from Dyke's Automobile and Gasoline Engine Encyclopedia
As the piston approaches the bottom of the stroke the ports on the exhaust side of the cylinder begin to align so that the spent gases can be pushed out on the upstroke. Meanwhile the intake ports remain misaligned so that the exhaust is not forced back into the carburetor.
This design did have some significant advantages over the poppet valves of the teens and twenties. The sleeve system was quiet, mostly because it used connecting rods rather than push rods and tappets which create a loud clattering sound.
Eliminating the pushrods and valves also held some potential advantages. In the days of weak alloys and sometimes marginal heat treatments poppet valve timing was unlikely to stay consistent over long periods of time, and problems with carbon buildup, poor valve seating and valve bounce all impacted performance and required frequent maintenance.
The knight sleeve valve system did not suffer from these types of problems. The connecting rods and secondary crankshaft used for the sleeves reduced problems with timing, and eliminated the danger of mistimed valves being struck by the piston. There was no need to regrind and seat valves, and carbon buildup on the valves was not a problem. In fact, it's believed that carbon buildup tended to help the performance of the knight engine because it made the seal between the sleeves tighter, leading to better compression.
The reduction in maintenance compared to other common engines was probably why the Knight was billed as having the 'engine you will never wear out." That was a bit optimistic of course. The same carbon buildup that helped to seal the sleeves better also caused plenty of wear on the sleeves, eventually making them loose enough to make the knight a real oil burner.
Eventually improvements in engineering and materials eliminated the primary disadvantages of poppet valves. Once maintenance concerns were less of a problem, cost and performance made poppet valves the clear winners in most applications. Still, the sleeve valve design is fascinating, and I'd love to be able to take one of them apart some day.
If you've ever heard of a Willys Knight then you probably know it has a somewhat unusual engine.
While most automobile engines use a poppet valve system, the knight was known for having a sleeve valve system instead. Now if you're reading this page, there's a better than average chance that you know the difference between a sleeve valve and a poppet valve, but just in case let's do a little review.
Your typical auto engine runs on a 4 stroke system, where every two rotations of the crankshaft can be divided into 4 main phases: intake, compression, power, and exhaust. During the intake and the exhaust strokes it is necessary to open valves for fuel and air intake and venting the exhaust gases. A poppet valve is usually positioned in an arrangement something like this.
A spring holds the valve shut while a cam actuates the valve during the brief period that it needs to be opened. Different valves are actuated by different cams so timing the valves is fairly straightforward.
A sleeve valve system looks more like this.
Rather than having two or more valves in the top of a cylinder there are two sleeves inside the cylinder and around the piston. The sleeves are controlled by connecting rods, linked to a small crankshaft which takes the place of the poppet valve's camshaft.
Interestingly enough, the sleeve valve system seems to have more in common with a steam engine than an internal combustion engine. Early steam engines had slide valves that controlled steam inlets and exhaust, but these sleeve valves are much more advanced than most steam chest slide valves in both timing and design. A common problem with slide valves was 'cutting' of the sliding surfaces due to force from the steam pressure in the cylinder, but a sleeve valve that wraps around the cylinder has pressure on all sides and so there is virtually no unbalanced force to cause cutting of the valve surfaces.
Each sleeve has two ports in it on opposite sides. One port is for exhaust, one is for the intake.
On the intake stroke, the left hand ports align creating an opening for fuel and air to be drawn into the cylinder. As the piston passes bottom dead center, the ports in the sleeve pass the intake passage sealing the opening. The piston continues upward compressing the fuel air mixture in the now sealed cylinder.
Near the top of the stroke, the fuel air mixture is ignited by the spark plug. The sleeves travel downward but stay just far enough out of alignment to avoid opening the exhaust or the inlet port.
As the piston approaches the bottom of the stroke the ports on the exhaust side of the cylinder begin to align so that the spent gases can be pushed out on the upstroke. Meanwhile the intake ports remain misaligned so that the exhaust is not forced back into the carburetor.
This design did have some significant advantages over the poppet valves of the teens and twenties. The sleeve system was quiet, mostly because it used connecting rods rather than push rods and tappets which create a loud clattering sound.
Eliminating the pushrods and valves also held some potential advantages. In the days of weak alloys and sometimes marginal heat treatments poppet valve timing was unlikely to stay consistent over long periods of time, and problems with carbon buildup, poor valve seating and valve bounce all impacted performance and required frequent maintenance.
The knight sleeve valve system did not suffer from these types of problems. The connecting rods and secondary crankshaft used for the sleeves reduced problems with timing, and eliminated the danger of mistimed valves being struck by the piston. There was no need to regrind and seat valves, and carbon buildup on the valves was not a problem. In fact, it's believed that carbon buildup tended to help the performance of the knight engine because it made the seal between the sleeves tighter, leading to better compression.
The reduction in maintenance compared to other common engines was probably why the Knight was billed as having the 'engine you will never wear out." That was a bit optimistic of course. The same carbon buildup that helped to seal the sleeves better also caused plenty of wear on the sleeves, eventually making them loose enough to make the knight a real oil burner.
Eventually improvements in engineering and materials eliminated the primary disadvantages of poppet valves. Once maintenance concerns were less of a problem, cost and performance made poppet valves the clear winners in most applications. Still, the sleeve valve design is fascinating, and I'd love to be able to take one of them apart some day.
Subscribe to:
Posts (Atom)