1942 - 1947 Chevrolet Shop Manual



	6-19

	to the oil manifold, thence through drilled passages in the bearing support webs in the cylinder block, to the four main bearings. The oil then passes through grooves in the bearings to the drilled passages in the other side of the cylinder block webs to the camshaft bearings. In this manner full pressure feed lubrication is supplied to all main and camshaft bearings. TIMING GEAR LUBRICATION Lubrication for the timing gears is supplied by conducting the oil from the front camshaft bearing, through a milled slot in the rear surface of the engine front end plate, to a nozzle extending out from the front and so aimed that the oil stream effectively lubricates the timing gears. CONNECTING ROD BEARING LUBRICATION Oil for the connecting rod bearings passes from the cylinder block fitting to the oil manifold, through a drilled passage in the cylinder block to the oil distributor. As the oil pressure builds up, the oil distributor valve opens and releases the oil into a drilled passage in the block; this passage connects with the short pipe fitting into the main supply pipe in the oil pan. From the main supply pipe the oil passes to the oil manifold in the oil pan, where it is distributed to the six oil nozzles. The six oil troughs in the oil pan are adjusted to the proper height so the connecting rod dippers will dip into the oil and supply lubrication at low speeds. As the engine speed is increased and the oil pressure is built up, the nozzle oil streams rise, and are caught by the dippers, forcing oil into the connecting rod bearings under high pressure, Fig. 37.	between the two hollow rocker arm shafts then distributed to all rocker arm bearings. A bleeder hole in each rocker arm supplies oil for lubrication of the valve stems and push rod sockets. Proper functioning of the oiling system is dependent upon proper adjustment of connecting rod dippers, oil troughs, and oil nozzles. IT IS VERY IMPORTANT THAT THESE ADJUSTMENTS BE CHECKED AND ADJUSTED EVERY TIME AN OIL PAN IS REMOVED OR A NEW OIL PAN INSTALLED. CONNECTING ROD DIPPERS The height of the connecting rod dippers is very important to insure proper lubrication of connecting rod bearings. The oil trough depth and connecting rod dipper height gauge, J-969-2 for regular 216.5 cu. in. engine, or J-1646 for the heavy duty 235.5 cu. in. engine, is used to check the height of the dipper from the machined surface of the Crankcase with the oil pan gasket removed. With the two side pins of the gauge resting on the Crankcase flange, Fig. 38, the end of the dipper should just touch the bottom of the cross bar of the gauge. If the dipper is lower than the gauge, a new dipper must be installed. If the dipper is higher than the gauge, it may be bent down to the correct position.


		Fig. 38—Checking Connecting Rod Dipper Height NOTE—The oil pan gasket must be removed during this operation. Checking the Oil Pan To check the oil pan proceed as follows: 1. Check the oil nozzle height for connecting rod dipper clearance, using the oil nozzle depth gauge, J-969-3, Fig. 39. Remove the oil pan gasket (if on the oil pan) and hook the edge of
	Fig. 37—Connecting Rod Bearing Lubrication VALVE MECHANISM LUBRICATION Oil for lubrication of the valve mechanism is tapped from the oil manifold and carried by a pipe, passing through the water jacket, to a fitting