TM 5-2420-230-24-2
B3.9 and B5.9 Series Engines
Piston (001-043)
Section 1 - Cylinder Block - Group 01
Page 1-79
The piston ring sets are also different. While both sets
consist of three rings, the top ring of the turbocharged/
aftercooled set has a keystone profile that operates in a
ni-resist insert cast into the piston. The naturally aspirated
top ring is square cut and operates in a groove machined
into the aluminum piston.
The 1994 automotive pistons utilize different top ring lo-
cations. The 160-hp to 175-hp ratings use 8-mm crown to
ring land pistons and 190 hp to 210 hp use 10 mm. The 1994
industrial pistons continue with the 14 mm ring position.
Overheating of the engine from a loss of coolant will cause
the cylinder to overheat, resulting in seizure of the piston.
Loss of piston cooling lubricating oil can also lead to piston
seizure.
Preparatory (001-043-000)
WARNING
Coolant is toxic. If not reused, dispose of in accordance
with local environmental regulations.
Drain the coolant. Refer to Procedure 008-018.
Remove the cylinder head. Refer to Procedure 002-
004.
L-757
