Many people have heard of Detroit Diesel Series 60 Top Liner Cooling or Top Cooled Liners, but don't know what
it really is. Here's a basic explanation: Starting with engine serial number 06R597515, Detroit Diesel starting drilling
holes in the block to allow coolant to flow around the top of the liner. This design change is to increase the cooling
at the top of the liner. A cooler liner allows for a number of benefits, including: decreased thermal expansion of the
liner and decreased cylinder temps. The liners have also changed to include a cooling channel around the top
of the liner just below the liner flange. This channel gives the coolant an area in which to flow.
The new and old style liners are not interchangable. Old style liners do not have the cooling channel and will block
the cooling passages in new style drilled blocks. This may cause pre-mature failure of the liner, block, or pistons.
New style liners also are not interchangable with old style blocks as the cooling channel machined in the liner
will actually cause the cylinder to run hotter. This is due to the air gap acting as an insulator from the block, and
not allowing heat to be conducted away into the engine block.
The following diagram shows the flow of coolant around the liner.
Top Liner Cooling Technical Definition:
An internal combustion engine including a cylinder block having at
least one cylinder bore and a cylinder liner concentrically disposed
within the cylinder bore and secured to the cylinder block. The
cylinder liner includes a main body portion and an upper margin. A main
cooling chamber surrounds a substantial portion of the main body
portion of the cylinder liner and has an inlet port and at least one
outlet port for circulating a coolant fluid about the main body portion
of the cylinder liner. A secondary cooling chamber is located about the
circumference of the upper margin of the cylinder liner. The secondary
cooling chamber has four inlet ports in fluid communication with the
main cooling chamber and disposed space from one another at equidistant
points about the circumference of the cylinder liner. Furthermore, the
secondary cooling chamber includes four outlet ports providing fluid
communication with the outlet port of the main cooling chamber. The
four outlet ports are located spaced from one another at equidistant
points about the circumference of the cylinder liner and between
adjacent ones of the inlet ports. The secondary cooling chamber further
includes eight discreet segments extending between the four inlet ports
and the four outlet ports such that fluid coolant is circulated from
each of the four inlet ports in opposite directions through adjacent
segments of the secondary cooling chamber toward a pair of the four
TLC Liner Installation Instructions:
The arrows on top of the liner are to be lined up with the 2 coolant holes in the block. See image below:
Install the Series 60 Liner as follows:
Be sure the block bore and counter bore area are clean, so the flange will seat properly. Block counter bore depth must be .3514 - .3533 inches and must not vary .0015 inches in depth around the circumference. No two adjacent block counter bores may range in depth more than .001 inches when gauged along the longitudinal block centerline.
Use proper installation tool to install liner. Lubricate the seal rings and crevice seal with clean petroleum jelly to help ease installation. Do not exert excessive force on the liner while pushing down.
Allowable Series 60 liner protrusion is .000 - .003 inches with no more than .002 inch variation between two adjacent cylinders. Be sure that the arrows on top of the liner are in line with the 2 coolant holes in the block.
Refer to OEM service manual for additonal service information.