Cylinder sleeve

Cylinder sleeve is the main thing in bore designs in engine blocks because it protects cylinder block from high wear,friction,and temperture resultant from combustion .



The other designs on the left incorporate separate liners. A liner is also called a sleeve.

1- Heterogeneous   "with liner " :

* A dry liner presses or shrinks into a cylinder that has already been bored . Compared to the wet liner,
this liner is relatively thin and is not exposed to the coolant, it's structure may be Cast iron block enclosing cast iron liner or Aluminum block enclosing cast iron or hyper-eutectic Al-Si liner with press-fitting .

** A wet liner is directly exposed to coolant at the outer surface so that heat directly dissipates into the
coolant.

To withstand combustion pressure and heat without the added support of the cylinder block, it must be made thicker than a dry liner.

A wet liner normally has a flange at the top. When the cylinder head is installed, the clamping action pushes the liner into position . The cylinder head gasket keeps the top of the liner from leaking.

*** The cast-in liner design encloses the liner during the casting process of an entire cylinder block .
It's structure may be Aluminum block with enclosing cast iron liner or Aluminum block with enclosing
PM-aluminum liner.