Dry Cylinder Liner
Dry cylinder liners are a cylindrical part fitted into an engine block to form a space in which the piston can reciprocate smoothly. Unlike wet liners, these do not come in direct contact with the engine's coolant. Generally these are made from cast iron or cast steel alloyed with chromium, copper or nickel.The aforementioned alloying elements help resist corrosion and also increase the wear resistance of the liners at higher temperatures.
Dry cylinder liners are manufactured separately from the cylinder block. This is necessitated due to the fact that since the liner needs to be comparatively more sturdy than the cylinder block, hence it's made from a comparatively superior quality material, that too with optimum precision. Since dry liners are used in a wide range of engines, these are manufactured in various specifications and dimensions, with the option of customization also available.
Types of Dry Cylinder Liners
Thin Walled Dry Cylinder Liners – Makes the engine lighter and more compact.
Loose-fit Dry Cylinder Liners – These are distinguished by the gap between the inner circumferential surface of the bore of the cylinder block and the outer circumferential surface of the liner.
Tight-fit Dry Cylinder Liners – These have no gaps between the aforementioned inner circumferential surface and the outer circumferential surface.
Advantages of Dry Cylinder Liners
These are very simple to install and service.
These ensure that there is no danger of water leakage either in to crankcase or the combustion chamber.
Due to the absence of heavy flanges at the top of these liners, cylinder centers can be reduced.
Their design ensures optimal cooling of their upper part.
Usage Preferences of Dry Cylinder Liners Amongst Manufacturers
Dry cylinder liners are preferred by Asian, African and North American manufacturers, most notable being general motors, Toyota etc. As for Europe, dry liners are still the second choice there. The reason for this dichotomy is just plain old usage habits of different manufacturers in different parts of the world.
However, it must also be noted that European manufacturers are gradually realizing the benefits of dry liners and thus have started to use these liners in their engine blocks. Although dry liners replacing wet liners altogether is still a far fetched idea, yet their usage is almost certain to increase in the coming years.