Rajo Motor and Manufacturing was a manufacturing company based in

Racine, Wisconsin Racine ( ) is a city in Racine County, Wisconsin, United States, and its county seat. It is located on the shore of Lake Michigan at the mouth of the Root River (Wisconsin), Root River, south of Milwaukee and north of Chicago. It is the List ...

in the twentieth century. The company built performance enhancing cylinder heads for

Model T The Ford Model T is an automobile that was produced by the Ford Motor Company from October 1, 1908, to May 26, 1927. It is generally regarded as the first mass-affordable automobile, which made car travel available to middle-class Americans. Th ...

cars that were designed by

Joe Jagersberger Joseph William Jagersberger (born Josef Wilhelm Jagersberger; February 14, 1884 – October 5, 1952) was an American racing driver and mechanical engineer. Background Jagersberger was born in Wiener Neustadt, southwest of Vienna, in Cisleith ...

(Rajo Joe). The company was named by combining the "RA" from Racine and the "JO" from Joe Jagersberger's first name.Joe Jagersberger's Biography
at the National Sprint Car Hall of Fame, dated 2007, Retrieved November 12, 2007 The heads were sold around the world. The company's

Los Angeles Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...

salesman

Rajo Jack Dewey Gatson, better known as Rajo Jack or his pseudonym Jack DeSoto, (July 28, 1905 – February 28, 1956) was an American racecar driver. He is known as one of the first African American racers in America.Joe Jagersberger Joseph William Jagersberger (born Josef Wilhelm Jagersberger; February 14, 1884 – October 5, 1952) was an American racing driver and mechanical engineer. Background Jagersberger was born in Wiener Neustadt, southwest of Vienna, in Cisleith ...

retired from driving after he had one of his legs amputated. Jagersberger continued to work for J.I. Case, as he had before the crash, until he decided to go out on his own. The company was formed in 1914 as Rajo Manufacturing. Jagersberger restructured the company in October 1919 after he designed a head with double the performance of the stock Model T head.

Models

Rajo Motor started out building

spark plug A spark plug (sometimes, in British English, a sparking plug, and, colloquially, a plug) is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air ...

s and other various engine parts. The first design was the Model 30 which had 4 exhaust ports and one intake port all on the right side of the head. The Model 31 had two intakes on the right and four exhaust on the left. The Model 35C, first known as the "Improved Rajo Valve-in-Head" and later as the Model C had two intakes and three exhausts on the right. The Model A used the stock intake ports on the block. It had two exhaust ports on the right. His Model B featured two intakes on the right and four exhausts on the left. It came in three versions. The BB featured a higher

compression ratio The compression ratio is the ratio between the maximum and minimum volume during the compression stage of the power cycle in a piston or Wankel engine. A fundamental specification for such engines, it can be measured in two different ways. Th ...

and the BB-R also included two

s per cylinder. Chevrolet work He also offered a modification to the 1941-52 Chevrolet "'' Stovebolt''" L6 OHV 15 bolt head, which added another set of 3 intake ports above the 3 originals, to permit adding (an) extra carburetor(s) on a separate manifold. Jagersberger died in 1952. The company closed in 1980.

References

{{reflist Companies based in Racine, Wisconsin Manufacturing companies established in 1919 Manufacturing companies disestablished in 1980 Defunct manufacturing companies based in Wisconsin