G Scale Model Train Forum banner

1 - 13 of 13 Posts

·
Premium Member
Joined
·
150 Posts
Discussion Starter · #1 ·
My son (10 years old) has decided his Science fair project will compare the pulling power of various (model) steam locomotives vs their cylinder size, total weight and other factors. With the help of friends we have collected pulling power data for a host of locomotives, but have been unable to find cylinder bore and stroke for most - and would rather not open cylinders on otherwise good running locomotives. Help completing the following table would be greatly appreciated.

Accucraft locomotives:

Engine Bore Stroke

K27 ? ?

K28 ? ?

2 cyl Shay 16mm? 32mm?

Garratt ? ?

4-4-0 ? ?

C-16 ? ?


Thanks!
Mark
 

·
Premium Member
Joined
·
150 Posts
Discussion Starter · #4 ·
Thanks Charles, but all the engines listed are Accucraft. And yes, we did run a few Asters, but as you pointed out the cylinder data is readily available. Now if I just had a bunch more Asters......
 

·
Premium Member
Joined
·
695 Posts
Mark,

Bore sizes for the following:

k-27, K-28, Garrett:
5/8" or 15.88mm

4-4-0:
1/2" or 12.7mm

...I'm pretty sure the bore on a 2cyl shay is the same as a ruby, which are 3/8" cylinders...16mm is over 5/8".

Somewhere I have the stroke sizes.
 

·
Premium Member
Joined
·
150 Posts
Discussion Starter · #7 ·
OK, looks like the C-16 and the Mogul (failed to mention previously) are the only two engines I still require data on.

BTW Ryan - the Accucraft site lists "D16 x 32" for cylinder size on the Shay. I agree with you, this is way too large, and 3/8" or about 9.5mm is probably the correct bore.
 

·
Registered
Joined
·
243 Posts
Uhh-- actually the Shay has bigger cylinders than the Ruby.  I have both a Shay (2 cyl.) and a Ruby (Ida) and the cylinders on the Shay are much bigger.  I think that the Superior and the shay have the same cylinders.


One of the tell tales is that the diameter of the cylinder body is bigger than the width of the valve chest on the Shay and the cylinder end caps have four bolts.  The Ruby has only two bolts and the outside of the cylinder body is the same width as the valve chest. 


BTW both of my engines are from early production runs.


Regards,
 
 

·
Registered
Joined
·
243 Posts
Oh Mark, if you need the weight on my Konrad kitbash we now have a digital food scale with a capacity of up to 11 pounds.


Regards, 
 

·
Premium Member
Joined
·
695 Posts
Eric, Mark.

Hazarding a wild guess, I would say the Shay must have 1/2" cylinders if they are bigger than a ruby. Although, the outside of a cylinder is nothing to go by, as this dimension varies depending on the engine and application the cylinders are being used on. While they would appear to be bigger on the outside, they are actually ythe same on the inside.

The only way to tell is to get someone with a shay to take the cylinder cover off and do a measurement with a caliper or some appropiate measuring device. I would imagine that the 3 cylinder shay shares the same cylinder unit, just with an extra attached at the end. I know someone on here has taken apart a 3 cyl recently, so maybe they will see this and share their findings.
 

·
Premium Member
Joined
·
150 Posts
Discussion Starter · #11 ·
Well, curiosity got the better of me, and I opened up one of my shay cylinders - bore is 12.6mm, basically 1/2". BTW - every single gasket surface on my Shay is leaking, so looks like I'll be opening up the other cylinder, and the steam chests, and the backs of the cylinders, etc. Oh well, at least they are easy to get to.

Still looking for data on the Mogul....it out pulled many of the bigger engines. It looks like available track adhesion is the limiting factor on most these tests. Next time we should use rubber track and sandpaper wheels to eliminate this problem....
 
1 - 13 of 13 Posts
Top