The cylinder bores in a new cylinder block are classified as # 0, # 1, # 2 or # 3 (Table 1) designating the specific size range for each bore and the appropriate cylinder liner that may be fitted to each bore. The classification number is stamped on the fire deck of the cylinder block adjacent to each cylinder bore.

A new standard size cylinder liner is classified as # 1, # 2, # 3 or # 4 as illustrated in Figure 1 and Table 1.

Although the block bores and liners should be measured to determine the liner-to-block clearance, the selection of a liner is narrowed down to only those in the appropriate classifications or possibly an oversize liner.

Before installing a liner in a used cylinder block, always slightly hone the block bore (refer to service manual section 1.1).

After honing the block bore, check the bore measurements to determine if a standard liner (classification # 1, # 2 or # 3) or possibly a # 4 liner can be used (refer to Tables 1 and 2). A push fit between the liner and the block is desirable. If an adequate push fit cannot be obtained, it may be necessary to bore the block to receive an oversize liner.

When it becomes necessary to install an oversize liner, the same care in selective tolerance fitting must be adhered to. However it may be more difficult to select an oversize liner since the size range is not broken down into classifications.

In deciding whether boring is necessary or not, keep in mind that each bore in a used block must not be out-of-round or tapered more then .002". If the average block bore is over 4.6285", the cylinder block should be bored oversize.

To determine what size to rebore the cylinder block for a # 4 or an oversize liner, each service liner used must be measured on the outside diameter for size in three places (under the flange, between the flange and ports, and above the ports). The cylinder bore size will be determined by the average liner measurement taken at the three positions. The liner taper is the difference between the O.D. at the .625" (15.88mm) and the 9.875" (250.83mm) dimensions from the top of the liner flange.

EXAMPLE:
Service Liner O.D. measures 4.6280"
O.D. size = 4.6280"
plus clearance = .0005"
bore size = 4.6285"

Then, 4.6285" + .001" boring tolerance will allow a bore size of 4.6285" to 4.6295" and a possible liner-to-block clearance of .0005" to .0015". The clearance tolerance is the dimensional difference between the liner O.D. and the block bore I.D.