Diesel engine cylinder liners are basically a hollow cylindrical shell that act as an enclosure in which the combustion takes place. The noteworthy thing here is that the aforementioned word hollow does not imply weakness, in fact these liners have considerable strength because they have to withstand high levels of hoop and thermal stress. Although these are generally made from cast iron, however, modern day demand for lighter engines has resulted in some liners being made from aluminum.
Diesel engine cylinder liners are extensively used, they are designed with precision, with their outer surface being corrosion and wear resistant. Furthermore, their design also ensures protection against extensive galling that usually takes place due to continuous motion of the piston. Owing to their usage in a various types of diesel engines, these are available in a wide assortment of dimensions and specifications, with the option of some customization also available.
Construction of Diesel Engine Cylinder Liners
Construction of these liners is done by centrifugal casting or sand casting for small and large liners respectively. The inner surface of diesel engine cylinder liners is always chrome plated for making it smooth In recent years, this smoothness has been found to have drawbacks such as it prevents the oil from spreading out properly, thus affecting liner lubrication in a negative way. This has been rectified to some extent by the use of porous chrome honing process.
Types of Diesel Engine Cylinder Liners
Diesel engine cylinder liners are basically of two types, these are :
Dry Liners – These have relatively thin walls as compared to wet liners. The distinguishing feature of dry liners is that these do not come in contact with the coolant, instead fitting closely against the wall of the cooling jacket in the cylinder block.
Wet Liners – Unlike dry liners, these do come in direct contact with the coolant. These liners generally have integral cooling passages. As a result wet liners are sometimes also referred to as water-jacket liners.
How to Increase the Life of Diesel Engine Cylinder Liners
Never overload the engine.
Always maintain correct operating temperature in the engine.
Always use the correct grade cylinder oil, that too in optimal quantity.
Periodically keep checking the wear rate of the liner, the liner is gauged at regular intervals to ascertain the wear rate.
Periodically check and clean the cylinder of abrasive particles.