Harley-Davidson VL Engine Case Prep
Preparing the engine cases on a Harley-Davidson VL is the first major step in a complete rebuild. This process covers disassembly, cleaning, and surface preparation before the cases are sent out for machine work. For related engine work, see cylinder and head prep and cam repair. For the full VL build context, visit the VL Tech archive.
Left-side case half at the start of teardown before any cleaning or prep work.
Right-side case half before disassembly and cleaning begins.
This is going to be a complete ground up build of a 1933 Harley-Davidson VL. Starting with the matched engine cases pictured above, I'll be building the motorcycle piece by piece until I have a complete motorcycle capable of making a cross country trip next fall. The build officially got underway on Black Friday when I set to work preparing the engine parts to be sent out to the engine shop for rebuilding. Every piece needed to be disassembled and cleaned before being sent, so the first weekend I spent a good deal of time in front of a blasting cabinet.
Removing Cylinder Studs
Cylinder studs being removed using a dedicated stud puller rather than the two-nut method.
To prep the cases for blasting, there were a few parts that needed to be removed first. We started by pulling out the four cylinder studs in the left side of the case. Snap-On makes a special tool just for removing studs and if you can get your hands on one it is much easier than the old two nut trick that most folks use in absence of the proper tool. The Snap-On kit includes a number of different sized collets each one made for a specific thread pitch and diameter. After selecting the appropriate sized collet, you screw it down onto the stud. A second piece slides over the collet and is held in place with an end nut. As you tighten the end nut the second piece presses down on the end of the collet closing it tighter on the stud. Once everything is locked in place, the entire tool is removed using a wrench. Then you disassemble the tool, remove the stud and move on to the next one. Each stud was easily removed in this way and none were damaged.
Removing Idler Gear and Shaft
Idler gear removed and shaft extraction in progress on the right case half.
On the right side engine case, the idler gear and shaft had to be removed. The idler gear is held on the shaft with a special split ring, which can be carefully pried off, allowing the gear to slide off the shaft. The inside of the shaft is threaded, so by threading a bolt into it, we were able to get a surface to pry against for removing the shaft.
Protecting Internal Surfaces
Bushings plugged and VIN masked to protect critical surfaces during blasting.
Besides removing parts, there were also some pieces that needed to be protected. The bushings in the camchest were still in good condition, so they were left in place. In order to keep their interior surfaces from being damaged in the blasting cabinet, each one was tightly plugged. I also taped over the VIN number to avoid accidentally erasing it while cleaning the cases.
Blasting the Case Halves
Case half with all critical holes plugged to protect bushings before blasting.
Next, both case halves were placed into the blasting cabinet and worked for about an hour.
Blasting in progress with steady movement to avoid damaging the aluminum surface.
Cleaning the Cam Cover
Cam cover hardware being removed after soaking fasteners with penetrating oil.
The cam cover was next on the cleaning list. On a V-series engine, the cam cover provides a mounting location for the oil pumps and the timer. All of these had to be removed before proceeding. These parts are held together with screws, so the first step was to apply liberal amounts of Kroil Penetrating Oil onto every fastener. We also matched every screw to the correct sized screwdriver to make sure that we got the maximum leverage without stripping the screw head.
Cam cover parts cleaned with lacquer thinner to remove grease and buildup.
The cam cover parts had a good layer of grime on them which also needed to be cleaned off. A short bath and brush with lacquer thinner got all the pieces cleaned up nicely.
Final Surface Finishing
Cam cover parts being finished on a wire wheel after blasting.
Once free of grease, these parts all went into the blast cabinet. The final step was to brush each part using a fine wire wheel to remove the residue and dull finish left from blasting. The result was a more even surface coloring and a brighter overall finish.