164 BULLETIN 173, U. S. NATIONAL MUSEUM 



BUDA ENGINE, 1924 



U.S.N.M. no. 30S310 ; original ; gift of the Buda Co. ; not illustrated. 



This is an example of the modern 4-cylinder, 4-cycle gasoline en- 

 gine built for use in motor-coach and truck service. The engine, 

 which is sectioned, is revolved by an electric motor to illustrate the 

 operation of the engine. 



This engine has a 414-inch base and 5i^-inch stroke and develops 

 53 horsepower at 2,000 revolutions per minute. The four cylinders 

 are cast in block and are jacketed for water cooling. The water is 

 circulated by a centrifugal pump regulated by a Fulton thermostat. 

 Intake and exhaust valves are of the mushroom type and located on 

 the same side of the cylinders. A 3-bearing camshaft operates the 

 valves. The cylinder head is of the type known as L-head. The spark 

 plugs are located at the centers of the cylinder heads. The pistons 

 are packed with three rings above the wrist pin and a wiper or oil 

 ring below. The crankcase is made of aluminum alloy. The crank- 

 shaft is counterbalanced and is supported in three bearings. It is 

 drilled for lubrication. An oil pump supplies the lubricant to all 

 bearing surfaces under pressure. The engine is equipped with 

 magneto ignition and a combination electric starter-generator. The 

 carburetor receives air through a centrifugal dust remover. 



WILLYS-KNIGHT AUTOMOBILE ENGINE, 1927-28 



U.S.N.M. no. 310292; original; presented by Willys-Overland, Inc.; not illus- 

 trated. 



This is a 6-cylinder engine of the Knight sleeve-valve type. It 

 has 177.9 cubic inches displacement and is rated at 20.7 horsepower at 

 300 revolutions per minute and develops 53-horsepower maximum. 



The valves are cast-iron sleeves with annular slotted ports near the 

 tops. These sleeves, two to a cylinder, fit one within the other with 

 the inside ones forming the cylinders within which the pistons work. 

 The sleeves are operated by short rods from eccentrics on two eccen- 

 tric shafts and move up and down a distance of about 1 inch. The 

 valves are adjusted so that the intake opens 10° after top center and 

 closes 35° after bottom center; the exhaust opens 60° before bottom 

 center and closes 5° before bottom center. 



OTHER GASOLINE AND OIL ENGINES 



There are many gasoline and oil engines included in the aero- 

 nautical and automotive collections of the Division of Engineering, 

 but not described in this publication. A few are mentioned below, 

 though many of equal interest are omitted. None are illustrated. 



