Got my feet wet, now more questions...

[chucketn]

I am studying “Flame Gulper” engines for my next build(#2). I am building a collection of free plans from Antony Davis, J. Ridders, Dr. Alfred Bachmann, the Candle Engine made from black pipe and a pipe cap, and one from Popular Science, and the Poppin from Live Steam. Any other free plan you know of for ideas?
I understand the basic principle and construction. Most of the plans call for a 2 ½” x 3” piece of cast iron for the cylinder,and cast iron for the piston. The Cylinder usually has fins cut into the outside. I understand this is to improve cooling of the hot gas from the flame.
My question is how critical is the diameter, and length of the cylinder? I have aluminum in a large enough diameter. Could I not make the cylinder from aluminum and the piston from brass? The hardest part for me will be to come up with a simple working valve that I can make.
I don't read German, but I think thie vaccum engine shown here: http://www.john-tom.com/html/SteamPlans.html uses an aluminum cylinder and brass piston. I'm using Google Translate gadget to translate some of the words.


Chuck in E. TN

 

[small.planes]

Cylinder out of either Alluminium or Brass (Messing),
Piston from Cast Iron (Gusseisen - should have the B double s, but Ive not got it on the keyboard...)
or Bronze, probably a leaded bronze.
There is an easily translated parts/materials list at the end of the PDF (pg 7)

hth

Dave

 

[wizardofwood]

Hi Chuck

This is my take on the german engine on the john-tom page. I think the plans actually show a steel cylinder pressed into an aluminium finned housing. I changed the valve to be more like the poppins, and made the bearing standards vertical rather than inclined. It wasn't much of a build log, but it does show the finished engine and some video of it running.

http://www.homemodelenginemachinist.com/index.php?topic=8960.0

 

[kcmillin]

Hey Chuck.

I have asked this question here and done some research on it myself. From what I came up with, if you want to use an aluminum cylinder, than using bronze for th piston should work. I have not done it myself but I have seen one working with what they called phosphor bronze, and they mentioned not to use an oil bronze. I do think that brass might be a good choice, being similar to bronze and I have seen it used many times in stirlings with aluminum cylinders.

Just a thought.

Kel

 

[chucketn]

I have a couple of crankshafts from lawn mower engines. Would they be suitable for piston material? They aren't big enough for cylinders. I do have some steel bar that might make a cylinder.
Any ideas for a source of Cast Iron for cylinders other than ordering online?

Chuck in E. TN