Toyota FJ GSJ10 Technical Manual page 32

" A water passage is provided between the cylinder bores. By allowing the engine coolant to flow between
the cylinder bores, this construction enables the temperature of the cylinder walls to be kept uniform.
" A compact block is achieved by producing the thin cast-iron liners and cylinder block as a unit. It is not
possible to bore a block with this type of liner.
" The liners are a spiny-type, which have been manufactured so that their casting exterior forms a large
irregular surface in order to enhance the adhesion between the liners and the aluminum cylinder block.
The enhanced adhesion helps improve heat dissipation, resulting in a lower overall temperature and
reduced heat deformation of the cylinder bores.
ENGINE — 1GR-FE ENGINE
A
A
Water Passage
Cylinder Block
Liner
Irregularly shaped outer
casting surface of liner
238EG12
238EG13