Little Engines "old" Atlantic?
Little Engines "old" Atlantic?
Was there ever an 'old' Atlantic casting set that was different or more complete / expensive than the current one?
I've got an engine here finished in the late 70s that someone is claiming is different / better than the current offerings. I have no idea if there is any truth behind that so I'd love to hear your input. If the answer is 'no' then OK. If it's 'yes' then I'll post some pics of it to verify.
-M
I've got an engine here finished in the late 70s that someone is claiming is different / better than the current offerings. I have no idea if there is any truth behind that so I'd love to hear your input. If the answer is 'no' then OK. If it's 'yes' then I'll post some pics of it to verify.
-M
Live Steam Photography and more - gallery.mikemassee.com
Product Development and E-Commerce, Allen Models of Nevada
Product Development and E-Commerce, Allen Models of Nevada
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Re: Little Engines "old" Atlantic?
Can't say with any certainty, but I think from prior discussion hearing the Atlantic/Pacific line changed from inside to outside admission (or vice versa), perhaps in the 80s?. Possibly related, I thought these engines had slide valves disguised in there, but the castings nowadays sure look piston valve.
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Re: Little Engines "old" Atlantic?
They are outside admission piston valves. This was done in order to keep the original valve gear. The thing is that there is pressure on the valve steam was as with conventional piston valves the stem has exhaust pressure or no pressure on it.
I may add the outside admission valve has less pressure them a slide valve as the pressure is equal all around the valve rather then pushing down on top of it.
I may add the outside admission valve has less pressure them a slide valve as the pressure is equal all around the valve rather then pushing down on top of it.
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Re: Little Engines "old" Atlantic?
If what Dave is saying is correct about the current LE Atlantic, then they have changed since the 70s. I have a friend who started his in '75 and it has slide valves with the steam chests cast to mimic the look of piston valves.
-Tristan
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Re: Little Engines "old" Atlantic?
Okay...lets set this straight
The Atlantic was the second designed 1-1/2" scale Little Engines loco in the 50's
as many know it ha a 1 piece cylinder block with "D" valves and a steam chest that when jacketed gave it a piston valve appearance
This remained this way until about 1983 to 85 (I have been unable to clarify the actual change date) when Moody Braun decided to opt for a 3 piece cylinder block with OUTSIDE admission piston valves.
eeThis block is a direct replacement/upgrade from the original block.e
The original valve liner design was flawed and had corrections made in the late 80's
With all the records I have there is no indication or evidence of there being a more complete or more expensive 4-4-2
the original 4-4-2 was based on the 3000 class SP Atlantics as was the 1" scale version
Mike
Little Engines
The Atlantic was the second designed 1-1/2" scale Little Engines loco in the 50's
as many know it ha a 1 piece cylinder block with "D" valves and a steam chest that when jacketed gave it a piston valve appearance
This remained this way until about 1983 to 85 (I have been unable to clarify the actual change date) when Moody Braun decided to opt for a 3 piece cylinder block with OUTSIDE admission piston valves.
eeThis block is a direct replacement/upgrade from the original block.e
The original valve liner design was flawed and had corrections made in the late 80's
With all the records I have there is no indication or evidence of there being a more complete or more expensive 4-4-2
the original 4-4-2 was based on the 3000 class SP Atlantics as was the 1" scale version
Mike
Little Engines
Re: Little Engines "old" Atlantic?
Is there a way to tell without opening the chest? Perhaps by looking at the travel of the valve? A real piston valve should have a shorter travel, yes?Soot n' Cinders wrote:If what Dave is saying is correct about the current LE Atlantic, then they have changed since the 70s. I have a friend who started his in '75 and it has slide valves with the steam chests cast to mimic the look of piston valves.
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Product Development and E-Commerce, Allen Models of Nevada
Product Development and E-Commerce, Allen Models of Nevada
Re: Little Engines "old" Atlantic?
Outside admission valves on a locomotive with outside valve gear require that the eccentric crank be set 90 degrees from where it would be with inside admission valves. The eccentric rod pin therefore leads the main pin instead of following it in forward motion. To me this gives the eccentric crank and eccentric rod kind of a lop-sided motion compared to the prototype, and a model equipped with inside admission valves.
Martin Lewis started this because he had inexperienced builders trying to fit round valves liners in a round hole without the proper fit and thus making the liner egg shaped. You were never going to get a piston valve to seal under those conditions. His idea was that a flat slide valve was easier to make seal. His point that the valves would wear in is true but at the expense of the valve gear wearing out much quicker because, as was pointed out, the greatly increased forces required to move the unbalanced outside admission slide valve.
Also on the slide valve, the radius rod on Walchearts gear (or valve rod on Baker gear) connects below the valve crosshead pin on the combination lever instead of on top as per the prototype.
Moodie Braun simply converted the slide valves to an outside admission piston valve with his three piece design, thus requiring no change to the valve gear.
Jim Kreider
Martin Lewis started this because he had inexperienced builders trying to fit round valves liners in a round hole without the proper fit and thus making the liner egg shaped. You were never going to get a piston valve to seal under those conditions. His idea was that a flat slide valve was easier to make seal. His point that the valves would wear in is true but at the expense of the valve gear wearing out much quicker because, as was pointed out, the greatly increased forces required to move the unbalanced outside admission slide valve.
Also on the slide valve, the radius rod on Walchearts gear (or valve rod on Baker gear) connects below the valve crosshead pin on the combination lever instead of on top as per the prototype.
Moodie Braun simply converted the slide valves to an outside admission piston valve with his three piece design, thus requiring no change to the valve gear.
Jim Kreider
Re: Little Engines "old" Atlantic?
Harlock wrote:Is there a way to tell without opening the chest? Perhaps by looking at the travel of the valve? A real piston valve should have a shorter travel, yes?Soot n' Cinders wrote:If what Dave is saying is correct about the current LE Atlantic, then they have changed since the 70s. I have a friend who started his in '75 and it has slide valves with the steam chests cast to mimic the look of piston valves.
Try looking at the front or back of the cylinder casting inside of whatever jacket liner you see. Examine the area between the round decorative covers for the main piston and "valve piston". If you have a slide valve engine you will see a horizontal part line between the halves. If you have a piston valve engine the block casting will be one piece.
Darren McNeely
and the sons of Pullman Porters, and the sons of engineers,
ride their father's magic carpets made of steel.
www.swlsonline.org
and the sons of Pullman Porters, and the sons of engineers,
ride their father's magic carpets made of steel.
www.swlsonline.org
Re: Little Engines "old" Atlantic?
Mike,
It's tough to tell without removing at least the outside jacket or at least removing a few of the jacket screws and peering in. The chest design on the D-valve cylinders is very distinctive and easily identified. If you have or can get a hold of a pre-80 LE catalog there are some good pictures in there showing what the valve chests look like. There is a small seam between the valve chest and the lower cylinder.
$.02
Ken-
It's tough to tell without removing at least the outside jacket or at least removing a few of the jacket screws and peering in. The chest design on the D-valve cylinders is very distinctive and easily identified. If you have or can get a hold of a pre-80 LE catalog there are some good pictures in there showing what the valve chests look like. There is a small seam between the valve chest and the lower cylinder.
$.02
Ken-
Re: Little Engines "old" Atlantic?
Mike,
I found a photo in my library that shows the D-valve block. May be tough to see with these 1024 px requirements.
Ken-
I found a photo in my library that shows the D-valve block. May be tough to see with these 1024 px requirements.
Ken-
Re: Little Engines "old" Atlantic?
kenrinc wrote:Mike,
I found a photo in my library that shows the D-valve block. May be tough to see with these 1024 px requirements.
Ken-
There 'ya go.
Darren McNeely
and the sons of Pullman Porters, and the sons of engineers,
ride their father's magic carpets made of steel.
www.swlsonline.org
and the sons of Pullman Porters, and the sons of engineers,
ride their father's magic carpets made of steel.
www.swlsonline.org
Re: Little Engines "old" Atlantic?
Hi all,
thanks for the enlightening feedback. Words from elsewhere also bolstered what was said here about the timeline of the slide valve vs. piston valve at LE.
Today I pulled one of the covers off and confirmed that it is the slide valve. Here it is. Quite clever really.
-M
thanks for the enlightening feedback. Words from elsewhere also bolstered what was said here about the timeline of the slide valve vs. piston valve at LE.
Today I pulled one of the covers off and confirmed that it is the slide valve. Here it is. Quite clever really.
-M
Live Steam Photography and more - gallery.mikemassee.com
Product Development and E-Commerce, Allen Models of Nevada
Product Development and E-Commerce, Allen Models of Nevada