The Birmingham age-herald., 1915-07-18
W|LLYS-KN|GHT ANNOUNCEMENT OF NEW OVERLAND CAR Equipped With Knight Type Motor at Lowest Price
 in History of Such
 Engines

This is a seaon of surprises in the motor car industry.
 The new developments have taken the form of multiplying the cylinders of the old type of motor. of radical price reductions, or a combination such as that covered by the Willys- Knight announcements which offers two radi- cal changes-one in motor design, the other in price. The price is the lowest at which car with a Knight type motor has been offered to the public
 Its reliability, remarkable power smoothness of operation and economy have made it famous throughout the world. One of its chief advantages is its characteristic of improving with use. It Is an established fact that the Knight type of motor gives even greater satisfaction the second and succeeding years than the first. It's simple design and small number of parts insures it against the various evils that frequently come under the head of motor troubles. Retimng is never necessary. There is no guess work. The entire action is positive and never failing
 Sleeve Valve Motor
 The important difference of the Knight type motor from poppet valve motor is in the valve arrangement. The Knight type is sleeve valve mo- tor. The valves are merely sliding sleeves. There are two-one inside the other sliding up and down btween the cylinder wall and piston In each openings are placed which. at the prop CT time in the action of the motor ot hpr init the charge of fresh gas from the carburetor to enter the combustion chamber and similarly for the burt gases to pass from the cylinder out into the muffler.
 1nasmuch as the power of any motor Is largely determined by having the fresh gas in sufficient quantity enter the cylinders at exactly the right mo- ment and upon the complete expulsion of all burnt gases also at exactly the right moment, the poppet valve inn poses certain limitations upon all pop pet valve motors.
 Necessarily the diameter of the pop pet valve is limited by diameter of the cylinders. Their accuracy as to time of opening and closing is made uncer- tain because dependent upon cams and springs.
 Sleeves Have Positive Action
 The large sleeve valves of the Knight type nlOIOf permit valve openings much larger than can be had with poppet valves. The sleeves have a pos itive action, as they they opened and closed by positively operated connect ing rods, and therefore. there is no un- certainty either to the time or ex- tent of the opening. It must always he exactly right and there will always be full opening regardless of the speed of the motor.
 There has been more or less gener- al idea among those only partly famil- far with the Knight construction. that the operation of the sleeve valves might offer some difficulty. This Is because it has not been known that the sleeves do not have to be made to a tight fit to hold compression as is true of the piston. The sleeves in opera ton are always covered with film of oil
 full operation of the Knight type motor than the fact that the sleeves are not called upon to retain compression Is the relatively slow motion of these sleeves Whereas in the WillYs- Knight motor the piston has a stroke of 4 lS inches. the sleeve valve travels but one inch at one half the motor speed ln other words, the sleeve valves travel at only one-ninth of the piston speed This means that If your motor Is trav- cling at the rate of 90 revolutions per minute. and which would be equivalent to a car speed of 24.6 miles per hour