Engine - Cylinder Block Distortion Limit Specification

85mitsubishi02

SUBJECT:

CYLINDER BLOCK DISTORTION LIMITS

NO. STB-85-09-009

DATE July, 1985

MODEL All Models

STB Revision
DISTORTION LIMITS ESTABLISHED

STB-85-09-009

A distortion limit of 0.1 mm (.004") has been established for the deck surface of all cylinder blocks.

SERVICE MANUALS AFFECTED This bulletin affected all Service Manuals as indicated in the table below. As reference to this bulletin, please write the STB number on each of the pages in the table.

1985 1984 1983
Mirage 9-91 NA NA

Galant 9-60 NA NA

Cordia/Tredia 9-63 9-60 9-62

Starion 9-50 9-50 9-49

Truck 9-100, 9-141 9-93, 9-133 9-94, 9-134
Montero 9-53 9-51 9-48

FIGURE 1:

MEASURING DISTORTION

Cylinder block distortion (warpage) is measured as shown in Figure 1. Place a straightedge diagonally across the clean top surface of the block in direction A-F, Fig. 1.

While pressing down lightly on the center of the straightedge, attempt to insert a 0.1 mm (.004") feeler gauge between the block and head at several points as shown in Fig. 1. Repeat the process with the straightedge in positions B-G, A-G, and C-E.

CORRECTING DISTORTION

1. Diesel engine cylinder blocks warped more than 0.1 mm must be replaced because grinding would result in interference between the pistons and valves.

2. Gasoline engine cylinder blocks warped more than 0.1 mm may be resurfaced. For the block and head combined, a maximum of 0.2 mm may be removed. If this amount is not enough to bring distortion within limits, either the block or head, or both, must be replaced.

FIGURE 2:

STANDARD HEIGHTS

The standard heights in Table 1 may be used to determine whether a cylinder block has been resurfaced previously. The height dimension is shown in Fig. 2.

TABLE I: STANDARD HEIGHTS

1.5L 256 mm (10.079")
1.6L 285.2 mm (11.228")
1.8L, 2.0L, 2.4L 284 mm (11.181")
2.3L, 2.6L 316 mm (12.441")