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Tornado 230 CI Engine Information / History

Contributed By: Ben Page

Who designed it, service history, what happen when Kaiser/Jeep realized they built a lemon-warantee problems. Is this engine a decendent of the Contenental 226. Any informantion on the development and use of this engine. Any printed info that I can access, books, archives, websites etc.

Credit for this engine, which Willys identified as the Tornado OHC went to its Chief Engineer since 1952, A. C. Sampietro who had come to Willys at that time from Europe where he had worked for Donald Healy of the Austin Healy empire. In that context Sampietro had attracted attention by developing a cylinder head for the Nash engine that increased its output from 140 HP to 189 HP. Furthermore, Sampietro had been involved in chassis design at Healy that contributed to the demise of the old, and he ascertained that it was not possible to combine a soft ride with good road-holding capabilities.

Development of the new Willys engine was influenced both by existing trends in the industry and Willys' heritage which included considerable experience with L & F head engines, overhead valves and even sleeve-valve engines.

From the very beginning, the development of the new Willys engine was heavily influenced by the hemispheric design. To substantiate Sampietro's claims he conducted exhaustive tests on existing 6 cylinder engines and changed them to hemi-head designs. As a result of Sampietro's belief in simple and lasting technology, a single overhead cam layout was adopted with hemispheric combustion chambers and the design was based around three basic precepts:

  1. There were to be as few components as possible between the valve and cam.
  2. The valve gear was to be light and rigid.
  3. The lash adjustment was to be simple, accurate and sturdy.

The design of the silent-type Morse chain was unique in that it was covered with a special chilled cast iron, selected for long life and compatibility with the cam lobes.

The crank shaft was designed by him to have maximum rigidity and he dismissed the concept of a 7 bearing engine in favour of a satisfactory 4 bearing crankshaft for heavy duty work.

Willys processed each crank shaft in a special salt bath for 2 hours at 1,025 degrees. This increased, said Willys, the engines fatigue life by 50% and made the journal surfaces hard enough to be compatible with heavy duty tri-metal engine bearings.

The Tornados' spheroidal combustion chambers, large valves, overhead cam and carbo-nitrided crank shaft are prime contributors to its long life and low maintenance costs. It is claimed that with a simple valve train there is at least 50% less likelihood of the need for valve train maintenance.

In terms of torque the Tornado engine was outproduced by a number of engines including the 235 cubic inch Chevrolet, 225 cubic inch Chrysler and the 240 cubic inch International-Harvester. None of these, however, matched the Willys' low rpm torque output and only one, the 198 cubic inch Buick V6, was capable of producing significantly more torque output per cubic inch of displacement than the Jeep engine.

I hope this answers some of your queries and, as for your question on the "lemon", I can't answer that. We have very few of these vehicles in Australia. We didn't have a problem with them, still don't have a problem, and we still run original Tornado 230 OHC engines satisfactorily.(see the sig block)

I can tell you that it was the first commercially-produced OHC motor (although there are some examples of other manufacturers in America who tinkered with the idea. 1949 Crosley, Duesenburg and Stutz) but this engine was the first that was commercially-produced in large quantities. An old mechanic told me that the main problem with the engine was that it was ahead of its time and required mechanics of that era to learn something new. They approached it with trepidation and it therefore suffered "bad press".

In the matter of service history, all I can say is that the engine is extremely easy to work on and maintain.

If your would like any further information re publications etc, please feel free to forward me a private E.

Hope this helps a little?
All the best,
Ben Page

  • 1942 GPW "Mr Peeps"(Restored-Factory Orginal)
  • 1943 Jeep Trailer "Jack"(Restored-Factory Original)
  • 1965 475 4X4 Pickup OHC "Wilbur"(Original) Daily
  • 1984 GW Limited
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