View Full Version : Flamesuckers (pics)

04-27-2007, 01:46 PM
Two flamesucker engines. Flamesuckers are so-named because they work by opening a valve and allowing the vacuum formed behind the moving piston to suck hot gas from a flame into the cylinder. The valve shuts and the hot gas quickly loses heat to the finned cylinder which causes it to condense and form a partial vacuum inside the sealed cylinder. External atmospheric pressure on the exterior of the piston is greater than the pressure inside the cylinder and the piston is forced to move by this pressure differential. Properly, these are called atmospheric engines for that reason.



04-27-2007, 03:00 PM
Nice, the flamelickers/suckers always draw a crowd when run

Al Messer
04-27-2007, 05:34 PM
Back in about 1950, "Popular Science Monthly" had an article about a 4 cylinder one with a "Z" type crankshaft with a single lobed cam operating the four valves. Made by a Goldsmith in England.

04-27-2007, 05:38 PM
Nice work,Marv.I hope they run better than my example.
I made the pistons too loose,and it doesn't run at all.One day I will make the effort and run up a couple of new pistons,as I am intrigued by these engines.

04-27-2007, 07:01 PM
Nice work,Marv.I hope they run better than my example.
I made the pistons too loose,and it doesn't run at all.One day I will make the effort and run up a couple of new pistons,as I am intrigued by these engines.

If you have a steel piston in an aluminum cylinder, the different expansion rates of the materials may be doing you in. Try using some 30W motor oil to form an (admittedly temporary) seal for the piston. The first engine shown runs better with a fairly heavy oil lubricating the piston. (Use light oil to lubricate the other moving parts.)

Note too that these engines start more easily if you preheat the cylinder with the alcohol lamp. If the cylinder is too cold, it will quench the hot gas before the valve has a chance to snap closed and, as a result, won't develop the partial vacuum needed to make it run. Also, experiment with the placement of the flame source. There's a "sweet spot" where the gas taken in is hot enough to make the engine run well.

They are intriguing engines because they make the connection between heat and mechanical motion so perfectly obvious.

04-28-2007, 12:48 AM
Marv,I have a cast iron piston and slide,running in a steel cylinder.
This is the only pic I can find at the moment:


it has a slide opposite the piston,which is actuated from the piston.
I will make new bits,these are definitely too sloppy:).

04-28-2007, 11:50 PM
Hi Marv, Here are my two flame licker engines.


POPPIN Vacuum Engine from Live Steam Magazine


Breisch/Peters Flame Licker Engine

Some builders use graphite pistons for less weight and no piston lubrication is necessary.Both of my engines use cast iron piston and cylinders. This keeps the expansion rate the same as the engine heats up. I have been using Starrett micrometer oil for lubrication with very good results. Very little burnt oil buildup. I think I had between .0005 and .001 clearance between piston and cylinder on both engines.


04-29-2007, 06:37 AM
Very nice and nicely done. One question or suggestion when posting pictures of engine projects. Makes no difference of what type. It would be helpful to the forum members if you identified if the casting were a kit, who sold it or if you cast it yourself. Same thing if it is a barstock or other type kit. R&W machine ship kits.

The second most asked question at shows after you made that!
Is where did you get the parts/kit. Or who sells the castings:D

04-29-2007, 09:39 PM
Hi PT,

I did the machining on both engines. The Poppin pictured was my second attempt attempt. The first was about 20 years ago without success. This put me behind about 10 years in the model engine building dept.

The Poppin engine is from plans from Live Steam Magazine It is made of barstock (steel, aluminum, brass and cast iron).

The Breich/Peters Flame Licker is made from a casting kit (castings only). I had to supply the steel & brass stock, hardware and alchohol burner (old door knob). I purchaced my kit from Jay Peters (now deceased). The kit and instructions were last being sold by Jared Shonely and information should be available through the Cabin Fever website.