Aerospace Engines A to Z
Aerospace Engines A to Z

Updated: 13-Aug-2019

Harold C. Johnston of Akron invented and made a steam engine of his own design for a possible aircraft of dubious construction.

The Harold C. Johnston airplane project
“Harold's plane project”

The engine that was built and tested
“The engine that was built and tested”

-It seems that earlier he made a 65 hp radial engine.

-The one we show is a horizontally-opposed two-cylinder engine giving 90 HP.

-It consists of three parts: the boiler, the motor itself and the condenser.

-Curiously the water tank is between the wheels and the vertical upright contains the condenser, which in the previous illustration is at the top of the unit. The fuel is behind the pilots.

Johnston's alternative twin-cylinder machine
“The alternative two-cylinder machine”

Engines of JOHNSTON

Model: Motor de vapor

Arquitecture: de 0 cilindros
Total Displacement:
Bore / Stroke: x
Boiler Pressure:
Power:
Weight:

Other details:

The author of this edition of Aeroengines AtoZ, through Aeroteca, collaborated on Version 2 of this video, which is presented here.

To understand the operation of the connecting rods, the 1929 Continental R 670 single-cylinder engine was chosen.

A demonstration of Version 3, improved at the author's suggestion, is also available on YouTube at a later date. This version shows bronze valve guides, improved valve spring movement, and the split crankshaft counterweights and front bearing balls also move.

The design is from Juan Soler, Sant Cugat, Barcelona

Below we show a flash of version 3

Counting also with the coloboration of JMC of Enginys Mecanics in Mataro, Barcelona