this applies to non-variocam plus M96 motors (basically, the early ones)
straightforward & easy; no need for any funky tools.
to do this right, you'll need a couple of spare parts:
(3) green camshaft plugs (996.104.215.54)
(8) microencapsulated bolts (900.385.275.01)
(2) o-rings (996.107.221.51)
(1) tube of green loctite
first, we need to explain some things. top dead center (TDC) occurs when a piston is at its uppermost position within the cylinder. it's the point at which the piston stops travelling up and begins travelling down. the tricky part is that TDC occurs TWICE during an engine's 4 cycles. the first time is on the compression stroke & the second time is on the exhaust stroke.
per the factory shop manual, we want to be at TDC compression when we time bank 1 (cylinders 1-3) and TDC exhaust when we time bank 2 (cylinders 4-6).
first things first. in the picture below, we're looking at the front of the engine. if the engine were in the car, we'd be looking back through the firewall toward the rear of the vehicle. bank 1 is on the left and bank 2 is on the right.
now we need to remove three of the little green camshaft plugs from the motor. there are six total cam plugs in the motor. in the photo above, you would normally see three. there would be three on the other side as well. they're already removed in this photo.
on the left side would be two plugs. remove the bottom one. on the other side of the motor on the other head, remove the bottom one. on the flywheel side of bank 1, there is only one plug. remove it.
what we've done is to remove the cover for the timing side of the exhaust cams and the index side of the intake cams. more on this in a minute.
now, put a 24mm wrench on the crank pulley and rotate the engine CLOCKWISE until you get close to TDC.
TDC is indicated by a notch on the pully matching a mark on the crankcase as shown in the photo below:
you can 'lock' TDC at the crank by inserting an 8mm bolt through the hole on the pulley marked OT. it will slide into a recepticle on the crankcase as shown in this photo:
now we should have the motor at TDC. we need to make sure we're at TDC compression before we proceed. to do this, look at the notch in the intake cam we uncovered (this will only have ONE notch in it). it should be pointing OUTWARD like this:
if it is pointing inward, rotate the motor 360 degrees to TDC again. now the notch will be pointing outward.
now we will check / set the timing on Bank 1. look at the end of the exhaust cam on bank 1. if the engine is timed properly, the notches will be straight up and down; perfectly parallel to the seam between the head & the valve cover:
if your timing is off, the notches won't line up; they'll look like this:
