318 Small-Block Budget Build, Part 2

Before you can place the crankshaft into the block, you need to install the rear main-seal and the upper bearing halves. The seal is installed with the lip facing in. Put it in with the lip facing out, and your oil will travel in the same direction-out.

Without putting any assembly lube on the bearings, carefully place the crankshaft in the block and do not spin it.

With the Plastigage installed, we torqued the main caps and then removed them. After removing the main caps, we found that we had .003-inch of clearance . . . works for us. Factory spec calls for .005- to .020-inch. Yes, we're a little closer than the factory spec calls for, but we generally like slightly less clearance on the rotating assembly.

With the crankshaft resting in the block, install a small piece of Plastigage on the journal. If you have a micrometer, you can check this dimension by mic'ing the inside of the installed bearing and the diameter of the crankshaft journal.

Now take the crankshaft out of the block, put your assembly lube on the bearing surfaces, re-install the crankshaft, and then after the bolts are properly torqued to 85 lb-ft, you can give it a spin to make sure it's not binding. TIP: always torque your bolts in three increments (e.g., 20-50-85 lb-ft).

After the crankshaft is installed, you need to check thrust endplay. You will need a dial indicator and mount for this. After mounting the magnetic base to the block and placing the plunger of the dial indicator against the crankshaft, zero the indicator and gently move the crankshaft from end-to-end to see how much endplay you have. Spec is .002- to .009-inch. We had .005-inch.

Now comes time to install the pistons. Place the bearing halves on each rod assembly.

We are fortunate enough to have rod-bolt caps to keep the bolts from nicking the crankshaft on their way in, but if you don't, you can use vacuum caps or a hose.

Before you install the pistons in the block-depending on what rings you use-you may need to lube the cylinder walls and pistons before installing them; follow the manufacturer's instructions. In our case, we're using basic moly rings, and we gave the pistons, rings, and cylinder walls a good coating of oil.

Ring compressors come in many different kinds-we used a band compressor. Place the compressor around the piston and ring assembly, and tighten it up. The bottom of the compressor had small protrusions that keep the compressor from sliding into the cylinder.