crover diesel
trad-4180 overview
The Mcculloch TRAD-4180
a diesel sibling to the TSIR-5190

The McCulloch TRAD-4180 engine was developed in the early 1970’s and at-heart a sibling to the TSIR-5190 program.  It shares similar design methodology and advanced ideas of which are ahead of its time.  It is a radial 4 cylinder 2-stroke diesel engine that is air-cooled and pressure lubricated.  Air induction is via a turbocharger and geared supercharger with an intercooler.  Displacement was 180cid and produced takeoff power of 180 hp at 2850 rpm with an estimated ready to fly weight of 300-330 lbs.  McCulloch was far enough along in development to conduct aircraft prototype testing in a Cessna Skymaster (as the rear engine).  Unfortunately the engine never went into production.  An internal company document indicates the program was successful and was not halted due to technical problems.  The halt was due to the sale of McCulloch to Black & Decker in the mid 1970’s and the subsequent termination of many of the McCulloch advanced development programs.

This Prototype engine is currently at PIMA Air & Space Museum in Tucson, AZ (  It was donated in 1990 by Shop-Vac who owned McCulloch at the time (McCulloch was acquired, broken-up and sold multiple times over the last 40 years).  This engine appears by inspection to be the prototype used in aircraft testing.  A second prototype also exists at the San Diego Air & Space Museum, however is a “mock-up” with external engine components only.

It is inspiring to reflect on the engineering drive of McCulloch and the ingenuity of the TSIR-5190 and TRAD-4180 engines.  These programs give much to consider as one ponders the current needs of light aircraft propulsion.

Below you will find a video showing an overview of this engine... enjoy!