1966 Ford Mustang - Project '66 - Ford 289 Short-Block Buildup Part 1 - Project '66 Engine Build

8 John prepares for the installation of the crankshaft by placing the main bearing halves into the bottom of the block. The No. 3 bearing is the thrust bearing (denoted by the thrust surfaces on the sides of the bearing) and often requires gentle persuasion to fully seat. John uses this small tapping hammer for just that. The rear main-seal half is installed at the rear of the block at this time.

9 With the bearings seated and a light layer of 30-weight engine oil lubricating them, the crankshaft can be carefully laid into place. John took our original crankshaft and turned the main and rod bearing journals .010 undersized, then polished the throws, chamfered the oil holes, and balanced the complete assembly with our new flywheel and damper as a matched set.

10-a Using the specs supplied by the shop manual, John torques down our main caps, then sets up his dial indicator to check crank thrust.

10-b Our setup was a bit on the tight side, so John adjusted the thrust with a few careful blows on the end of the crankshaft (a process you really don't want to watch). We used ARP fasteners wherever we knew they wouldn't be seen, such as these main-cap bolts.

11-a The Speed-Pro ring package were using is a file fit set, meaning the builder sets the finish gap and the rings are filed to this setting. First, John uses an aluminum tool to square the bare ring in the finished cylinder bore and measures the end gap with a feeler gauge.

11-b The ring is then placed on a ring grinder (even a hand file will do) and material removed. The ring is squared in the bore and checked again until the correct gap is achieved.

11-c Once the rings are ground to their proper gap, John assembles the rings to the piston. Read the ring packaging for proper ring orientation on the piston.

12 To prepare the block to receive the piston assemblies (fully dressed with their rings), John applies a healthy coating of transmission oil to the cylinder walls with a paper towel. The towel removes any dust and dirt just before installation, while the transmission fluid aids as an installation lubricant while helping the rings seal on initial startup.

13-a There are many different ring compressors on the market, but John prefers to use this style with the quick-release pliers-type handles. He first sets the piston-ring position on the piston by rotating the rings so the end gaps are not on the thrust sides of the pistons. The compressor is installed over the piston and the connecting rod (pre-assembled to our pistons) is lowered into the cylinder bore. With a few careful taps with the end of his hammer, John installs the piston into its bore.