Volkswagen Engine Building Tech Info
These are freeze-frame images from the VW engine building video. There are a lot of up-close and personal shots like this throughout the tape. You can see a video segment from this tape on the VW Oil Cooler Seal Faq page.
Bolting the case halves together without having the dowel pins properly aligned can cause serious damage. In this instance, the crank nose bearing was rotated slightly, probably just before it was dropped into the case half. This bearing came from an engine that was "professionally" built. The unsuspecting owner installed the motor and drove it around like this, ruining both his crank and engine case in the process.
Here is a shot of a couple of rear main bearings on the heel of the crank. The bearing on the left is the correct one for the crank. The bearing on the right has a standard-size internal diameter, but it's mounted on a crank that has been reground to .010" under. These are the kinds of things to look out for when test fitting your parts.
Getting a camshaft that fits correctly can be a problem, because there is really nothing on the camshaft assembly that is adjustable. It either fits or it doesn't, and knowing how to tell the difference is a key part of any engine rebuild. If it doesn't fit right, you will usually have to replace part or all of the camshaft assembly. Can you tell what's wrong with the way the cam fits in this picture?
Case evaluation is one of the most important parts of any engine rebuild. If you make a mistake here, you will regret it later. In this picture, two of the main bearing saddles have been brought together to demonstrate case fretting. When the center mains become shiny from rubbing together, it is unlikely that the case will ever be able to maintain sufficient crush on the center main bearing saddle, even after align-boring.