Here's a question for everyone !
I'm part way through the rebuild of my VW T4 ABL engine, for the second time, but this time because of an overheating problem rather than the traditional and well documented crankshaft/timing pulley failure.
Having removed the cylinder head and after stripping it down to just the head I tried it on a sheet of glass while applying hand pressure only and was, in some places, able to ( just ) insert a 0.10 mm/ 0.0039in feeler gauge blade. This is the maximum that VW say is acceptable as deviation from perfectly flat/non warped. I then took a cast iron truly machined plate, wrapped it with 400 grit W+Dry paper, lubricated with WD40 and tried to flat out the areas where the 0.10mm blade would not insert. This took me down to 0.08mm, repeated took me to 0.65mm. This all took me about 2 hours, 1/2 sheet of W+Dry and a few calories. I blued the glass and tried the head but with only 0.35mm to play with the blue coloured the whole head.
Having given you the preamble my question is this: The head is fitted using stretch bolts fitted in four stages, stages 1 and 2 are torqued, stages 3 and 4 are "quarter turn 90 degree" no mention is made of using an actual/accurate angular device. Stage 2 torque is 40nm. What torque figures should I be looking at for stages 3 and 4 or is everyone's quarter turn the same?
Before any one asks , I have both printed manuals available and VW's dealer electronic manual (Elsawin) and none of them mention tolerances with stretch bolts!!