IT IS ADVISABLE TO LOAD TO AUXILIARY ENGINE SLOWLY. THIS IS BECAUSE SUDDEN LOADING LEAD TO OVERHEATING. THIS IS BECAUSE, THE CONTACT BETWEEN THE LINER AND SKIRT IS A LINE CONTACT WHICH IS MACHINED TO GIVE AN ARC OF 90 DEGREE EXTENDING OVER THE FULL DEPTH OF SKIRT.
WHEN THE ENGINE IS LOADED SUDDENLY, SIDE THRUST INCREASES AND TEMPERATURE OF PISTON SKIRT INCREASES IN THE WAY OF CONTACT AREA AND THE ARC CHANGES AND IF THIS ARC IS INSUFFICIENT AND CONTACT AREA DECREASES, THEN OVERHEATING MAY OCCUR.
TO AVOID THIS PROBLEM SKIRTS ARE MADE UP OF ALUMINIUM-SILICON AND SKIRT IS MADE TAPER IN SHAPE WITH THICKER SECTION AT TOP AND THICKER SECTION AT LOWER PARTS. FRICTION REDUCING COATING IS ALSO USED IN SKIRT.