The first major step of engine assembly is installing the crankshaft. While it is simple enough to insert the bearings and drop the crank in place, there are certain checks that need to be made before all is known to be right. Some of these checks, such as runout and bearing clearance could be made during the mock-up assembly, but the crank end-play needs to be verified after the main caps are torqued in place. Here are some points to pay attention to when installing the crank.
OEM cranks differ from most high performance cranks in the way the journal corners are fin
Rear main seals are typically a two-piece rubber lip-type arrangement in older engines, wh
Assembly oil is all it takes to properly lube the bearings during installation. We use Chi
On engines with flanged thrust bearings, it's important to "set" the thrust bearing during
Crank thrust clearance is measured by a dial indicator at the end of the crank. Use a pryb
Bearing caps must be installed in their original order and orientation. Most caps are numb
Some piston designs are symmetrical, and can be installed in any bore, while others with o
Loading the pistons and rods into the block marks a major milestone on the way to completing a build. There are several areas where a builder can get into trouble here, so careful assembly procedures are a must. It's best to first fully assemble all of the piston/rod assemblies, complete with rings, bearings, and lube, before knocking the first one in a hole. The orientation of the parts is important here. If using the stock rods, they should be numbered when the engine is disassembled, so that they can be replaced in the same position and orientation upon re-assembly. Many OEM rods are marked by the factory; if not, mark both the cap and rod.
For the beginning builder, pressed pins are best left the to machine shop, but the rod/piston orientation should always be checked. If putting together rods with floating pins, the rods need to be oriented correctly when the pistons are hung. Most rods, including aftermarket units, have a large chamfer on one side of the big end, and little or no chamfer on the other side. The rod needs to go in with the large chamfer to the cheek of the crank journal. A high quality lube such as Torco Assembly Lube from Valco Cincinnati is best for the pins. Lube the bores of the piston and rod, as well as the pin itself. Tru Arc style pin locks are easily installed with snap ring pliers, however most piston manufacturers these days supply Spiro Lox. Spiro Loxs are nearly failure-proof.
Spiro Loxs are installed by first stretching out the Loxs to separate the coils, and insta
It pays to take extra time in getting organized for this part of assembly, laying all of the components out on the workbench, in an order corresponding to their final position in the engine. Each hole should have a piston, rod, rings, and wristpin specific to its cylinder, laid out in order. The job is to load these parts into eight assemblies, and then install them in the engine.
Master engine builders can detect potential problems while assembling an engine just by feel. As each operation is performed, check the parts and feel for any snagging or binding. Make sure that the bearing seat fully into position in the rods, the rings fit the grooves smoothly, without hanging-up, sticking, or binding, and the pin retainer locks are seated fully in their grooves. There really is no margin for error in installing the reciprocating assembly. Each part should fit together without having to be forced into position. When the pistons are installed in the block, care must be taken not to hang a ring up on the deck, which can easily bend or break a ring. If something doesn't feel right, stop and investigate. Get the short-block done, and the engine project is well on its way to completion.
The ring manufacturer will typically provide a chart with the ring stagger, which is the p
As with main bearings, rod bearings may need extra chamfer to clear the journal radii of a
There are many types of ring compressors, but the tapered-bore type is the best. These are