Aerospace Engines A to Z
Aerospace Engines A to Z

Updated: 17-Sep-2023

Sadler Radial Engines Inc, of Coupeville, WA. (now Constant Pressure Engines Inc). Initially run by William Sadler, apart from building ultralight aircraft, he created this company that took Alex Pong's Dragon to market, and later he created a larger engine known as R-1745U, larger than the original Dragon.

Sadler, R-1745U
“Sadler, R-1745U”

-It has many VW parts, such as pistons. It has six radial cylinders in two rows of three, coupled with the cylinders interspersed.

-The crankshaft has two crank pins at 180°.

-It delivered 45 HP at 2,450 rpm, and it gave way to another slightly larger model, the R-1765U.

Sadler R-1765U
“Sadler R-1765U”

-This air-cooled engine was very similar, with six radial cylinders, carburetor, and double electronic ignition.

-It gave 65 HP at 3,000 rpm weighing 108 pounds dry.

-Due to economic difficulties, this company has been for sale for some time. In their projects there was an 85 HP and a 110 HP engine.

Engines of SADLER.

Model: R-1745-U

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

Other details:
Model: R-1765-U

Arquitecture:
Cooling:
Total Displacement:
Bore / Stroke:
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 version 3

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