Aerospace Engines A to Z
Aerospace Engines A to Z

Updated: 05-Jul-2021

In the 1970s, Otto Pulch, as a member of the EAA, presented prototypes of engines based on BMW motorcycle cylinders.

-The first engine was a three-cylinder for motorized gliders. It had a vertical crankshaft, and a reduction and reverse gearbox, lowering the rpm from 3 to 1. It displaced 1,500 cc to give 75 CV.

-This engine gave way to the 6-cylinder radial versions with direct output for the propeller in a classic way.

Motor Pulch 003A
“Pulch 003A”

-The Pulch 003B had 6 BMW R100S cylinders, displacing 2,900 cc and delivering 180 CV at 5,500 rpm.

Pulch engine on bench
“Pulch engine on bench”

-Subsequently, projects such as the one shown on the bench, and the one carried out in 1991 came out.

Pulch con cigüeñal vertical. Año 1991
“Pulch with vertical crankshaft. Year 1991”

Engines of PULCH

Model: 003

Arquitecture:
Cooling:
Total Displacement:
Bore / Stroke: x
Power:
Weight:

Other details:
Model: 3 cyl. radial

Arquitecture:
Cooling:
Total Displacement:
Bore / Stroke: x
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