Circa 1949

Design History :-

The SUPER ATOM 1.8 cc designed by Vladimír Hruška, in Czechoslovakia. The SUPER ATOM 1.8 is a development of the first small batch of ATOM 1.8 made at the end of 1945.

Design Features:-

The design of the engine is a typical first postwar, long stroke, self ignition, plain bearing, piston controlled combustion, "T" type side scavenging, three axial attachment lug type crankcase.

Specifications:-

Specifications:
Bore:	12mm	0.472”
Stroke:	16mm	0.629”
Swept Volume:	1.81ccm	0.11 cu-in
Weight:	127g	4.47oz
Recommended rpm:	4000-6500 r.p.m.
Recommended prop:	11"x5" -- 12” x 5”

Observations:-

The engine featured here is an orginal Super Atom 1.8cc diesel.It's a real sweet little engine.but a slightly different from the the normal Atoms and replicas by the ring, that connects the cylinder to the crankcase . Another special future is the piston's rare construction details .There is always a problem to find a proper way,prevent the piston pin moving in the channels inside the cilinder.Mister Hruska, the designer, made a kind of (perliet) "cocon", with inside thread.
Inside the piston is a aluminium socket with the same thread,which is holding the pin.so its a "closed in" pin.! A very clever solution,...also very light. Most Chech engines have also an aluminium contra piston that keeps the weight down,easy cold adjustment, and also very tight fit when engine warm up! Smart solution.
For this engine I had to make a new piston because the orginal was not good enough for running .I made a special ftapper, M 9 X 1mm from silver steel to make it possibel to cut a tread inside the piston. Now it runs just fine with great compression.

Click the play button below to view a short video featuring the starting and running of this interesting little engine