Friday, June 1, 2007
“How do I remove the slotted plugs (screws?) in the oil control valves?”
Heat the case to about 200F and unscrew the things with a suitable screwdriver. If it’s an early case the slots are concave. Brazilian made stuff uses a shallower flat groove.
The screwdriver was a VW-specific item. Most American VW mechanics made their own, as I did. But the tricky bit was how to hold the crankcase whilst unscrewing the plugs. One method that works is to bolt that case-half to the top of the work-bench... assuming you’ve drilled a suitable pattern of holes to accept the studs :-) Another is to secure that half of the crankcase to a milling fixture designed to accept it, which should be available in any shop that does much VW work since the same fixture is used when opening up the cylinder bores for larger jugs.
If you have a MIG welder, a common method of removing stubbornly threaded plugs, broken studs and so forth is to weld a nut to the thing. Polishing the surfaces bright, establish a good ground, lay the nut (a large one is best) onto the slotted oil plug and weld the inside of the nut to the plug. This also heats the crankcase in that area and the plug can usually be unscrewed with only a moderate amount of torque. In fact, if you’re planning to use the engine in an airplane you’ll want some means of safety-wiring the plug. A drilled nut, welded to the plug, works quite well, although it’s a bit heavy.