Assembly

Slightly worn or scratched inlet valves can be reclaimed by lapping them on a piece of fine crocus cloth on a flat surface, but it is suggested that new inlet valves be installed.

INSTALLING CYLINDER BLOCK

Position cylinder block gasket and block on crankcase according to markings made prior to disassembly. Using cap screws with lock washers, secure cylinder block to crankcase.

INSTALLING CRANKSHAFT

If the crankshaft is fitted with oil seal rings, install rings. Position ball bearings and crankshaft in crankcase, making sure the drive end of the crankshaft is positioned as marked before disassembly.

If one end of the crankcase is counterbored for holding a bearing, be sure the crankshaft is installed through the correct end of the crankcase.

Carefully press crankshaft and bearings into crankcase using arbor press.

Position a new rear end cover gasket, when used, over the rear end of the crankcase, making sure the oil hole in the gasket lines up with the oil hole in the crankcase. Position end cover with oil seal ring, if used, installed over crankcase and end cover gasket. The end cover should be positioned correctly in relation to the oil holes in the gasket and crankcase. Secure end cover to crankcase with cap screws and lock washers.

If the opposite end cover requires an oil seal which was removed on disassembly, a new seal should be pressed into end cover. Position new end cover gasket and carefully install end cover over crankshaft and to crankcase, avoiding damage to the seal. Secure end cover with cap screw and lock washers.

PISTONS AND CONNECTING RODS

If new wrist pin bushings are to be used, they should be pressed into the connecting rods so that the oil hole in the bushing lines up with the one in the rod. The new bushings should then be reamed or honed to provide between 0.0002 in and 0.0007 in. clearance on the wrist pin. Position connecting rod in piston and press in wrist pin so that lockwire hole in the pin aligns with that of the piston. Install new lockwire through piston and wrist pin and lock same by snapping short end into lockwire hole at the bottom of the piston (Fig. 7). Teflon plugs in wrist pin ends may be used instead of the lockwires (Fig. 22).

Install piston rings in correct location with ring pipmarks up (Fig. 24). Stagger the position of the ring gaps.

Prelubricate piston, piston rings, wrist pin and connecting rod bearings with clean engine oil before installing them in the compressor.

Remove connecting bolts and bearing cap from one connecting rod. Turn crankshaft so one of its connecting rod journals is in the downward, center position. Compress the rings with a ring compression tool and insert the connecting rod with piston through the top of the cylinder whose journal is down. Position and attach the bearing cap to the connecting rod, making sure the bolt lock washers are properly positioned on the cap. Tighten connecting rod bolts evenly and bend the two new lock washer prongs up against the hex head of the bolt. Install the other connecting rod and piston in the same manner.

FIGURE 25 - UNLOADER MECHANISM

UNLOADER MECHANISM (Fig. 25)

The unloader pistons and their bores must be lubricated with special lubricant piece number 239379 (dimethyl polysiloxane) prior to installation. If new unloader kits are being installed, the pistons in the kit are already lubricated.

Install the unloader pistons in their bores with caution against cutting the grommets or distorting the back-up rings. Position unloader plungers in their guides and slip them in and over the tops of the pistons.

Install the unloader spring seat in the cylinder block; a small hole is drilled in the block for this purpose. Position the saddle between unloader piston guides so its forks are centered on the guides. Install the unloader spring, making sure it seats over the spring seats both in the block and on the saddle.

Install inlet valve seats if they have been previously removed. Position and install inlet valve guides, then drop inlet valves in their guides. There should be a loose sliding fit between guides and valves.

CYLINDER HEAD ASSEMBLY

If previously removed, the discharge valve seats should be installed. Drop discharge valves into their seats. Install discharge valve springs and cap nuts.

Place the inlet valve springs in the cylinder head. Use a small quantity of grease to hold them in place, just enough grease to keep the springs from falling out. Place cylinder head gasket on cylinder block. Carefully align cylinder head assembly on block and install cap screws with lock washers. Tighten securely and evenly cap screws that hold cylinder head to block.