Engine Assembly

Use kerosene on the reamer during this operation. Remove the reamer from the bar to prevent scratching the bearing and remove the aligning bushing and reamer bar. Blow out all chips from the crankcase and the oil lines with compressed air.

Fig. 30— Camshaft Bearing Staking Tool
When replacing a rear camshaft bearing, re-move the old bearing and file burrs from around opening. Drive new bearing into place with special driver, lining up oil holes in the bearing with the oil holes in the cylinder block. Line ream both the center and rear camshaft bearings.

Assemble the camshaft to the cylinder block and check the fit of the camshaft in the center main bearing, with a feeler gauge. This clearance should be from .002" to .004".
Fig. 31— Camshaft Bearing Reamer
Camshaft
The camshaft is designed to assure quiet operation, combined with accurate valve timing. The contour of the cams is carefully worked out to take up the valve clearance gradually. The valve lifters are located slightly off the center line of the cams. This design results in spinning the lifter so the cams do not engage the same point on the lifters, each time the valves open, resulting in long valve lifter life and quiet operation.
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The machining operations are performed on special designed machines to assure accurate relationship of the cams, resulting in a smooth operating engine.
Camshaft inspection is rigid. They are all checked on a fixture which compares each cam contour with a master cam.
The following is a list of the sizes of the cam-shaft bearing journals: Front bearing 1.808"-1.809". Center bearing 1.776"-1.777". Rear bearing 1.620"-1.621".
Whenever a camshaft is removed from an engine it is important that these dimensions be checked with a micrometer for out of round. If the journals exceed .001" out of round, the cam-shaft should be replaced.
Another very important inspection operation, when the camshaft is removed from the engine, is to check it for alignment. The best method is by use of "V" blocks and a dial indicator as shown in Fig. 32. The dial indicator will indicate the exact amount that the camshaft is out of true. I f it is out
Fig. 32— Checking Camshaft Alignment
more than .002" dial indicator reading, the cam-shaft should be straightened. When checking, the high reading of the dial indicator indicates the high point of the shaft. This point should be chalk marked so you can tell exactly where to apply pressure when straightening.
When straightening, the camshaft should be supported on the front and rear bearing journals in "V" blocks in an arbor press. Pressure should be applied to the high point of the center bearing journal, the point that was chalk marked during the inspection.
NOTE— During the straightening operation care should be taken to protect the center bearing journal to prevent damage to its surface.
After the camshaft has been straightened, it should be re-checked to be sure that it is within .002" dial indicator reading for alignment.

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