Types of Piston
SOLID SKIRT, OPEN-ENDED
This type is very strong but heavier and has its skirt connected to its head region all the way round. It is necessary to allow more clearance, especially at the top of skirt to avoid seizure.
TRANSVERSE SLOT, OPEN-ENDED
Such a piston is thermally compensating and can usually be operated at smaller clearances at the top of the skirt in the interests of noise reduction.
SOLID SKIRT SLIPPER
This type of piston has no thermal slot but the skirt is heavily cut away in the pin axis to reduce weight and avoid swaying. It is also more rigid and usually needs greater clearance than other types, but is the strongest one.
TRANSVERSE SLOT SLIPPER
Contrary to solid skirt slipper type, this type has a cast or milled transverse slot in the oil ring groove for thermal compensation. Smaller clearance at the top of the skirt is required, in the interest of quiet operation.
