IO-390-D Series Engine Maintenance Manual
72-30
© 2020 Avco Corporation. All Rights Reserved
Page 222
March 2020
IO-390-D Series Engine Maintenance Manual
(2)
As the cylinder barrel approaches the crankcase, catch the piston ring compressor as it
drops off the piston skirt.
(3)
As the cylinder assembly pilot is entering the crankcase, align the cylinder hold-down
studs with the holes in the cylinder flange.
(4)
Push the cylinder until the cylinder flange makes contact with the crankcase.
(5)
Install a vented plug in each spark plug hole to prevent the entrance of foreign materials.
Figure 27
Piston Ring Compressor (ST-485)
Figure 28
Install the Cylinder
G.
Install the cylinder base hold-down barrel nuts (Figure 17) on the thru-studs and cylinder
hold-down studs.
CAUTION
TO ENSURE CORRECT CYLINDER INSTALLATION, TORQUE THE
CYLINDER NUTS IN THE SPECIFIC SEQUENCE IN FIGURE 29.
H.
Torque the cylinder base hold-down barrel nuts as follows:
(1)
Torque the 1/2 in. nuts to 300 in.-lb (25 ft.-lb) (33.9 Nm) in the sequence shown in Figure
29.
(2)
Torque the 1/2 in. nuts to 600 in.-lb (50 ft.-lb) (67.8 Nm) in the sequence shown in Figure
29.
(3)
Install the 3/8 in. nuts on the remaining cylinder base studs. Torque these nuts to 25 ft.-lb.
(34 Nm). The torque sequence for these nuts is optional.
Figure 29
Sequence of Tightening Cylinder Base Hold-Down Barrel Nuts
