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February 2015

Clark Sintz: His Later Years

By Paul Harvey

Last month, I chose to write about an engine pioneer from Ohio, Clark Sintz, and detailed his early years in Springfield, Ohio.  Amazingly, he patented his first engine design in 1886, making him one of the earliest gas engine makers of the entire country. Being inspired to do further investigation by the 1891 Clark Sintz engine displayed in the Founder's Engine House at the museum, I discovered that Clark was an inventive genius who would rather move on to the next idea and challenge instead of profiting from the one he had just completed.  Soon his interest focused on boats and automobiles.  This fascinating tale begins in 1893 when Clark, at age 43, had just moved to Grand Rapids, Michigan, to have access to Lake Michigan to build launches that utilized his marine engines, and to continue his career.

After a brief venture into four-cycle engines during 1891 and 1892, such as the one displayed at the Coolspring Power Museum, Clark turned his attention to the development of the two-cycle engine.  Probably his most significant patent, number 509,255 of November 21, 1893, was the perfection of the three-port, two-cycle design.  This is shown in Photo 1. This engine used three ports and had no valves, drawing the gasoline from the injector into the transfer port, and scavenging the air from the crankcase.  It featured a piston-tripped, electric ignitor.  The three-port, two-cycle design is still used today in many applications.  Photo 2, taken from Cassier's Magazine of July 1893, shows this engine as a stationary model with two flywheels and belt pulley.

By July of 1894, the new Sintz Gas Engine Company of Grand Rapids, Michigan, employed 65 people, a tribute to his new two-cycle marine engine design.  To house this flourishing business, an impressive structure, four stories high, and measuring 45 feet wide by 80 feet long, was located on 242 Canal Street, Grand Rapids, Michigan.  The firm built launches ranging from 16 feet to 46 feet long, all powered by Sintz engines.  Despite the success, Clark soon tired of the new firm and sold out to his shareholders to form the Wolverine Engine Company.  He chose a different name as he did not want the "mails to get mixed!"  More about this later in the article. The conflict arose when Sintz wanted to replace his existing engine with a new "uniflow" two-cycle design; patent number 592,669 of  August 22, 1895.  Although history differs a bit here, he apparently did not completely divorce himself from the Sintz Gas Engine Company, as he assigned four other patents to it after 1894.

Photo 3  shows the pristine 1893 Sintz marine engine located at the Penobscot Marine Museum in Searsport, Maine.  Probably the oldest marine engine in the USA, it was purchased by a gentleman from Maine in 1893, never used, and put in storage for a century.  It is now a prize in their collection.  Taken from an old advertisement, Photo 4 shows the Sintz marine engine of 1893.  Note the lever that could vary the pitch of the propeller as well as reverse the blades.  Ingeniously, this lever also controlled the stroke of the fuel pump, keeping the engine at a constant speed regardless of the load.

Photo 5 depicts Clark and his two sons sometime in the late 1890s.  That is Clark to the left, 1850-1922;  Guy L. Sintz in the middle, 1875-1940;  and Claude Sintz to the right, 1876-1956.  His sons worked with him on many projects and future developments.

Unlike most two-cycle marine engines, the Sintz used a governor.  Photo 6 is taken from the Wooden Boat's article about the Penobscot Marine Museum's 1893 Sintz engine. Interestingly, Clark patented this governor, number 426,337, on April 22, 1890.  It is the same governor as used on Coolspring's four-cycle, 1891, engine.  The photo shows how the governor, by a roller on a lever arm, controlled the stroke of the fuel pump.  The entire governor action could be controlled by the propeller reversing lever mentioned above.  Hence, propeller pitch, direction and engine speed could be controlled easily by the governor and the lever.

This 3 horsepower, 800 rpm, Sintz marine engine was made in 1896.  See Photo 7.  It is now in the collection of the Gray Marine Engine division of Continental Motors Corporation.  Most marine engines built before 1900 had a base plate mounting, while after 1900, the mounting flanges were at crankshaft centerline to lower the engine's center of gravity in the boat.

Clark's other love was the automobile, and he found that his two-cycle engine was equally well adapted to it, as it was for boats.  One of his first vehicles produced in Grand Rapids, Michigan, is seen in Photo 8.  It is a Haynes-Apperson chassis vintage 1894, using a two-cycle Sintz engine.   Sintz introduced his "horseless carriage" in the September, 1897 issue of Horseless Age.  Shown in Photo 9, it featured a 6 horsepower Sintz two-cycle engine and a Reeves Variable Speed transmission.  Clark proudly stated that it would attain 12 miles per hour and climb any hill.  Photo 10 shows an advanced Sintz chassis of 1897.  It featured a 16 horsepower, two-cycle Sintz engine.  It is unclear whether the Sintz Gas Engine Company or Wolverine built these vehicles.

As mentioned earlier, Clark sold his interest in the Sintz Gas Engine Company in order to establish the Wolverine Motor Company of Grand Rapids, Michigan.  His two sons, Guy and Claude, were included in this venture.  In 1895, 19-year-old Claude obtained the first patent for the new two-cylinder Wolverine engine. As Claude was a minor, Clark was appointed guardian of the patent.  I am unable to find this patent.  However, Clark's patent of March 27, 1900, number 646,322, and shown in Photo 11,  was issued to the Wolverine Motor Company.  Depicting a two-cylinder, two-cycle engine, it featured variable ignition timing enabling the engine to operate in forward or reverse rotation.  Again tiring of the new company, the Sintzs sold the Wolverine Motor Works to C. L. Snyder in 1902, to begin manufacturing the Sintz automobile.  Wolverine changed ownership and location several times but flourished until 1955, eventually making large diesels for both stationary and marine use.

Sintz Automobile Company was opened in Detroit, Michigan, in 1902 to manufacture a five passenger tonneau with a two-cylinder, two-cycle engine.  See Photo 12.  The lever to the right controlled the transmission as well as the clutch.  Clark had patented this three-speed, constant mesh transmission and clutch in 1903;  number 773,430.  Although very successful, only six were sold when lack of capital forced him into liquidation.  It was time for Clark to move on.

The old Sintz Gas Engine Company of Grand Rapids fared a bit better in its future,  In 1902, it was bought by Ora Mulford and consolidated with the Michigan Yacht Company in Detroit, Michigan.  Here, according to Beeson's Marine Directory,  it was the "largest yacht and gasoline engine builder on the great lakes."  They offered both the Sintz two-cycle engine and the King four-cycle engine in their yachts.  Note Photo 13.   A smaller ad, Photo 14, shows the Sintz yachts built in 1906, by the above firm.  At that time, Mulford acquired two partners, Paul and David Gray.  The Gray Marine Motor Company, formed in 1925 in Detroit, became one of the longest-lived marine engine builders in the country.

Guy Sintz continued with various engine businesses for his entire career.  Working in Marshall, Michigan; Detroit, Michigan; Pittsburgh, Pennsylvania;  and York, Pennsylvania;  he finally re-united with his brother Claude in 1923 to become a  factory superintendent for him.  Claude Sintz initially formed his own marine engine firm in Grand Rapids, and produced the "Leader" marine engine, as shown in Photo 15.  His interest then returned to farm equipment, and he had several patents in that area. He became a member of SAE in 1917, and formed his own firm, the Claude Sintz Company, to make specialty automotive parts.  It is still in existence under different management.

Clark Sintz was granted 17 patents from 1870 to 1911.  See Photo 16.  His most significant was the 1893 patent of the three-port, two-cycle engine.  This design revolutionized the marine engine business and it is still used today.  However, his last patent, number 986,092, of March 7, 1911, was the most advanced.  He invented the automatic transmission for automobiles!   He depicted the engine directly driving a three-cylinder, radial hydraulic pump, the output of which was controlled by his uniquely designed valve, that then operated a three-cylinder, radial hydraulic motor to power the wheels.  One lever controlled forward, neutral and reverse!  The farther the lever was pushed in either direction, the faster the vehicle traveled; either forward or reverse.  Simple. This would be the hydrostatic transmission that we know today in so many applications.  He sold this patent to the Manly Hydraulic Drive Company of Philadelphia, Pennsylvania.

After the  failure of the Sintz automobile, he spent two years in Panama in charge of the plantation equipment for the United Fruit Company.  Upon return to the United States, he and his wife, Virgie, settled in New Orleans, Louisiana, in 1907.  There he opened a small machine shop and continued his love of inventing and experimenting, as well as doing job work for others.  Finally, the couple bought a small farm in Waveland, Mississippi, in 1914 and retired on the beautiful Gulf of Mexico coast.  His grandsons enjoyed spending their summer vacations with them.  Ironically, he was struck by an automobile while crossing a street there and died of the injuries on July 12, 1921.  Virgie passed away soon after, and their remains were returned to the Ferncliffe Cemetery in Springfield, Ohio.  Note Photo 17.  This concludes the tale of one of Ohio's most unique and inventive geniuses.


1. Wooden Boat,  March-April 2010,  No. 213, "Time Machine." 

2. Antique Automobile,  March-April 1972,  Vol. 36,  No. 2,  "Sintz's Important
          Contribution to the Birth of the Automobile."

3. Highlights of the Life of Clark Sintz,  Notes written by his son, Claude Sintz,
          about 1946. 

4. Dialogue with Bob Sintz, Clark's Great Grandson.

5. Penobscot Marine Museum Searsport, Maine.

6. Cassier's Magazine,  May 1893

7. Vintage Advertisement, as noted.

Sintz 3-Port 2-Cycle Engine Patent

Photo 1: Sintz patent for the three-port two-cycle engine

Sintz Cassier's July 1893

Photo 2: Sintz three-port two-cycle engine from Cassier's Magazine, July 1893

Sintz Engine Penobscot Marine Museum

Photo 3: 1893 Sintz marine engine

Sintz Marine Engine

Photo 4: 1892 Sintz marine engine

Clark and Sons

Photo 5: Clark Sintz, Guy Sintz, and Claude Sintz

Sintz Marine Governor

Photo 6: Sintz engine governor

Sintz Marine Engine

Photo 7: Three horsepower, 800 rpm Sintz marine engine

Sintz Auto 1894

Photo 8: Sintz 1894 automobile

Sintz Auto 1897 

Photo 9: Sintz 1897 automobile

Sintz Chassis 1897 

Photo 10: Sintz chassis of 1897

Sintz First Wolverine Patent 

Photo 11: Sintz first Wolverine patent

Sintz Car Grand Rapids 

Photo 12: Sintz automobile 1903

Sintz Yacht Harper's 1902 

Photo 13: Ad from Harper's Magazine

Sintz Yachts 1906 

Photo 14: Ad for Sintz engines

Claude Sintz Leader Engine 1906 

Photo 15: Ad for the "Leader" marine engine

Sintz Patent List 

Photo 16: List of Clark Sintz's patents

Clark Sintz Head Stone 

Photo 17: Clark Sintz's grave in Springfield, Ohio


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