PISTON WEAR

Horowhenua Chronicle, 28 September 1927, Page 2

PISTON WEAR

Wear of automobile pistons after 2,000 miles running of the car average between one and two-thousandths of an inch, according to figures compiled by the American Research Foundation

“Original clearance in a new engine is from three to four one-thousandths of an inch,” the bulletin states. After running 2000 miles the space between the piston and the cylinder wall is increased 40 per cent. For economical running of the engine and preservation of the life of the car, an entirely different grade of lubricating oil must be used from this period on.

“Wear inside the cylinder is constant, and the grade of oil must be changed again after 10,000 to 20,000 miles when the clearance has increased to 100 per cent more than its original space. While the figures may be accepted as general experience, it is impossible to lay down a definite rate of wear for all engines. There wall be differences according to whether aluminium or cast iron pistons are used, and a high-speed motor must receive more wear through the additional number of piston strokes for a given mileage. If laboratory' tests are accepted it seems certain that air filters will greatly recKico wear, while it must not be forgotten that thinned oil will increase the friction.