SECTION G Cylinder Block and Liners CYLINDER LINERS (4.108 ENGINES) The cylinder liners fitted to the 4.108 series engines are centrifugally cast alloy iron, they are an interference fit in the cylinder block parent bore and of the thinwall dry type. Reboring of these liners is not possible and new liners should be fitted when a rebore would normally be con- sidered necessary. The exception is 4.108 refrigeration unit engines which can be rebored to 0.020 in (0,51 mm) oversize. It must be noted that the oversize pistons for these engines are only suitable for this type of application due to the special operating conditions.
Dimensional checks of the cylinder bore are carried out by means of the gauge tool shown in Fig. G.1. When checking liners each one should be measured in three positions - top, centre and bottom; the read- ings being taken parallel and at right angles to the centre line of the cylinder block giving six readings for each cyl inder bore. When checking the fitted internal bore of a new thin- wall liner it is advisable to allow a period of time to elapse for the I iner to settle. 1. Remove all the various components from the cylin- der block. (Refer to the appropriate sections for details of their removal). 2.
Using a shouldered metal disc slightly smaller on the outside diameter than the parent bore dia- meter and a suitable press, press the liners care- fully out through the top of the cylinder block. NOTE: Support the block locally in the area of the top of the liner. 3. Lightly lubricate the outside of the liner with clean engine oil ready for fitting, 4. As the liner must protrude above the cylinder block top face and not be pressed fully home when fitted correctly, a solid stop washer should be available designed to give the correct liner protrusion. NOTE: The limits for liner protrusion are given on page B.3 and may be checked as shown in Fig. G.2. 5.
Press the liner into the bore progressively until it reaches the solid stop washer. 6. Bore and finish hone the liners to the dimension quoted on Page B.3. NOTE: Where boring equipment is mounted on tile top face of the cylinder block fit a parallel plate between the boring bar and cylinder block face. Such a plate should be thicker than 0.027 in (0,686 mm). 7. Re-assemble the engine components to the cylinder block. (Refer to the appropriate sections for assembly of these). To Renew Cylinder liners G1 Earlier 4.99 engines had only one seating ring at the bottom of the liner (see Fig. G.3). 4.107 and 4.99 cylinder liners have pre-finished bores.
Under normal circumstances, the liner would only need to be renewed during major overhaul, but should it be necessary to remove the liner for any other reason, this can be carried out without removal of the crankshaft. If at any time, the cylinder liners are removed and these same liners are to be refitted, then before they are removed from the cylinder block, they should be CYLINDER LINERS 07 and 4.99) Cylinder liners fitted to 4.107 and 4.99 engines are of the centrifugal cast iron wet type. They have flanges at the top and are sealed at the bottom by means of two rubber sealing rings which fit in machined re- cesses in the cylinder block. G2