The Difference Between Wet and Dry Cylinder Liners

Cylinders liners are called several names in industry. It can also be referred to as sleeves. Thus, cylinder liners and cylinder sleeves are one and the same thing.

The barrel or bore that the piston moves up and down may be either integral with the engine block, or be a completely replaceable separate item. Most diesel engines come with replaceable cylinder liners. The most common agricultural tractor with a sleeveless or liner less engines are some of the Ford / New Holland engines. Most of the other, including, John Deere, Farmall, Allis Chalmers, IH, Case, David Brown, Massey Ferguson, Perkins, Cummins and Kubota are predominantly sleeved engines.

The primary advantage of using a cylinder liner is that it will become damaged after the robust process of movement and combustions that occurs in it. At the top of the sleeve (in the combustion chamber) the temperature can be as much as 593 degrees Celsius (1100 Fahrenheit). The piston reciprocates in this cylinder liner at a speed of approximately 1800-5000 rpm, depending on application and design.
Replaceable liners can be easily pressed out, and a new liner be pressed in. There is portable equipment to perform this pressing in and out right on the machine, without the need for transport to a machine shop. However, the larger diesel engines will require removal from the machine and transport to the machine shop for full liner /sleeve replacement.

Another advantage of using sleeves / liners is that the engine block can be manufactured with less expensive cast iron, while the liners are manufactured with special alloys, making it tougher, harder, and resistant to heat and wear. These added alloys can have chromium, nickel, or molybdenum.

Engines with the bore directly into the engine block, like Ford Tractor engines, are referred to as “wet sleeves,” as the coolant circulated directly onto it, being cooled by convection. The blocks with are referred to as “dry sleeves” are cooled via conduction heat transfer.

After the initial wear and tear or operation, the engine block itself is re-bored to a larger diameter to fit oversized pistons. With repeated re-boring, there comes a time where re-boring has reached its limits, and a replacement cylinder liner has to be bought and installed. Thus, a sleeveless engine can be made into a sleeves engine when necessary.

Ford Tractor engines typically have liners fitted with a ridge or flange at the top. This acts as an added sealing feature, separating the water jacket from the combustion chamber and cylinder head.

The sealing of the water jacket and from the cylinder head is also supported by using specially made o rings that can be fitted to the top and bottom of the liner, depending on application and engine design.

Ontario Parts Hotline is a premium provider of Kubota Tractor Parts and Kubota PTO Parts.