Clean all passages with steam or compressed air. Inspect all oil passages and main galleries. Check the oil passages at
the same time as the water jackets are inspected. Clean the oil passages with a rifle rod and blow them dry with clean
compressed air. Inspect all machined surfaces for cracks, burrs, and pitting. Smooth down all rough and pitted surfaces
with a fine mill file. Make sure that all machined surfaces are smooth and clean. It is very important that all machined
surfaces be smooth so the gaskets will seat properly, eliminating any possibility of leaks.
c. Repair.
(1) Cylinder block. Replace the cylinder block if cracked or warped, or if the intake valve seats are burned or
cracked beyond repair.
(2) Core-hole plugs. Inspect the core-hole plugs. If there are rust streaks or signs of corrosion around the
outer edges of the plugs, they are leaking and must be replaced. Drill a hole through the plug and remove it
from the cylinder block. Clean the plug hole carefully and remove all rust, scale, and corrosion from the plug
seat. Coat the outer surface of the new core plug with fast-drying gasket sealer and start the plug in the
block, making sure that it is square with the face of the block. Use a wood or metal driver made to fit the
inside diameter of the plug and drive in the plug flush with the cylinder block.
(3) Studs. Inspect all studs for wear, warpage, and corroded, damaged, or stripped threads. Remove all
defective studs and check the threads in the cylinder block. Install new studs and coat the threaded
surfaces with light engine oil.
(4) Cylinder ridge. If the cylinders have a ridge at the top of the cylinder bore, remove the ridge, using a
standard ridge reamer or hone.
(5) Reboring. If the cylinders are worn more than 0.008 inch, rebore the cylinders oversize and hone them until
the bores are not more than 0.001 inch out of round or tapered more than 0.001 inch. Remember that the
tapered bores must be larger at the bottom than at the top of the cylinder. When reboring the cylinders, be
sure to follow the instructions supplied by the manufacturer of the boring machinery.
(6) Honing. If the oscillating movement is properly controlled and regulated during the honing procedure, the
finished hone will form a diamond pattern on the cylinder walls. This surface will aid the initial run-in
lubrication and the wearing in of the piston rings. Do not attempt to hone the cylinders to obtain a highly
polished, smooth finish, with no hone
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