928 four valve cam timing for humans.
Tools; 17mm socket, 27-30 combo wrenches, dial indicator, Star-8 bit for cam journal, glossy magazine cover.
1. Perform WSM up to page 15-130.
2. Set both bank cam wheels to center of adjustment range in slot, tighten cam nut while counter holding exhaust cam.
3. Set tick marks on cam wheel to align with tick marks on backing plate. Install and tension belt at TDC.
4. Rotate carefully two full turns back to TDC. Stop if you encounter solid resistance, and investigate.
5. Turn CW until #6 intake cam has the lobe pointing straight up from lifter (cam on heel of lobe).
6. Set up dial indicator on lifter of intake #6 with preload (or plunge) of >4mm. Indicator shaft perpendicular to lifter face. Zero gauge.
7. Ignore crank location. Rotate crank clockwise slowly until dial indicator has unwound according to the table below;
~~~~~~GT/CS cams = 3.1mm
~~~~~~85-86.5 cams = 2.0mm
~~~~~~S4 cams = 2.0mm
8. Tear 20 x 40mm strip from glossy magazine cover. Remove rear journal cap from #6 intake cam and fold strip once to ~20x20 square, then lay on journal. Install and snug journal cap back on over strip to lock cam.
********WARNING - DO NOT TURN CRANKSHAFT YET*********
9. Counter hold #6 exhaust cam, and loosen cam bolt 17mm with socket. Insure the three 5mm screws are out or loose on cam wheel.
10. gently rotate the crank either direction to 20 degrees after TDC. Insure you use the AFTER TDC mark, not the before TDC mark.
11. Check belt tension, adjust now if needed.
12. Counter hold exhaust cam, tighten cam 17mm bolt on cam wheel.
13. Remove glossy magazine strip from rear cam journal, reinstall journal cap.
14. Rotate crank so that cam lobe on cyl #1 is pointing straight up from lifter.
15. Set dial indicator up on intake lifter Cyl #1 with > 4mm preload and indicator shaft perpendicular to lifter face.
16. Ignore crank location. Rotate crank clockwise slowly until dial indicator has unwound according to the table below;
~~~~~~GT/CS cams = 2.8mm
~~~~~~85-86.5 cams = 1.6mm
~~~~~~S4 cams = 1.8mm
17. repeat steps 8-13 above, substituting cyl #1 in place of cyl #6.
*****DO NOT MOVE CRANK UNTIL CAM WHEEL BOLT IS LOOSE*****.
18. Recheck tension, insure cam journal caps are free of magazine strips, insure journal caps are tight, and rotate back to TDC. The ticks in the cams and backing plates should line up closely, depending on wear of cam wheels, and crank and oil gears.
This is a pic of a home made alignment tool for a S4, pic by Erkka. (click for a bigger one, adjust to sizes and make one yourself)