IO-390-D Series Engine Maintenance Manual
© 2020 Avco Corporation. All Rights Reserved
72-30
March 2020
Page 221
IO-390-D Series Engine Maintenance Manual
15.
Cylinder Installation
NOTICE:
Use a cylinder kit when installing a new cylinder. If a new cylinder #3 is installed it will
be necessary to install the fitting for the manifold pressure line that connects to the EIS
modules. Refer to Appendix A for fitting installation instructions.
If all cylinders are to be installed, install them by their firing order 1 - 3 - 2 - 4.
CAUTION
INSTALL THE CYLINDER BASE OIL SEAL RING (FIGURE 23) AROUND
THE CYLINDER BASE. DO NOT USE ANY ADDITIONAL SEALANT OR
GASKET MATERIAL WHICH COULD DETERIORATE WHICH COULD
CAUSE A REDUCED TORQUE ON THE CYLINDER BASE STUDS.
NOTICE:
Do not re-install the cylinder base oil seal ring which had been removed during cylinder
removal (and re-used as a support for connecting rods). Use a new cylinder base oil seal
ring.
A.
Install a new cylinder base oil ring around the cylinder base for each engine cylinder.
B.
Apply a light coat of engine oil mixture to the cylinder base oil seal ring.
C.
Lubricate the inside diameter of the cylinder barrel with engine oil mixture (15% pre-
lubricant (STP or equivalent) and 85% SAE No. 50 mineral base aviation grade lubricating
oil) to the depth of the piston rings, approximately 2 in. (5 cm).
D.
Apply one or a combination of any of the following lubricants to the outer three threads
(Figure 25) on all of the crankcase thru-studs and cylinder hold-down studs (Figure 26):
•
Parker Thread Lube
•
Mixture of 60% SAE 30W engine oil and 40% Parker Thread Lube
•
SAE 30W engine oil
•
Mixture of 90% SAE 50W engine oil and 10% STP
Figure 25
Figure 26
Stud Thread Location for Lubricant
Crankcase Thru Studs and
Cylinder Hold-Down Studs
E.
If not already done, install both rocker shafts in the cylinder head (Figure 24).
F.
Use the Piston Ring Compressor (ST-485) to install the cylinders (Figure 27) as follows:
(1)
Assemble the piston ring compressor (ST-485) over the top piston rings and install the
correct cylinder over the piston on the corresponding connecting rod, pushing the piston
ring compressor ahead with the cylinder barrel (Figure 28).
