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:
if your timing is off, now we need to set it. rotate the engine about 1.5 full rotations. as you approach TDC on the second rotation, check the timing marks. keep rotating the engine until the notches on the bank 1 camshaft are perfectly aligned with the head. once you're there, verify you're at TDC compression by looking at the single notch on the intake cam. it should be pointing OUTWARD.
once your timing marks are lined up & you've verified TDC compression, it's time to change the timing.
on the back of bank 1, put a match mark onto the oil scavenge pump (THIS IS IMPORTANT). remove the 10mm bolts and gently tap out the scavenge pump.
scavenge pump:
match mark:
tap it out:
now what you should see is this:
this is the camshaft sprocket. it is adjustable. loosening the four bolts will decouple the camshafts from the crankshaft, allowing you to alter the timing. LOOSEN, but don't remove, the four bolts. rotate the crankshaft to TDC (it's ok if you rotate the motor a tad backward). tighten the four bolts & check the timing notches on the bank 1 camshaft. if you are:
1) at TDC compression (intake cam index notch facing OUTWARD)
2) your bank 1 timing notches are lined up with the head
you have timed bank 1. don't re-install the scavenge pump yet; we'll get there.
now we need to time bank 2. to do this, we need to be at TDC exhaust. rotate the crank ALMOST one full rotation. as you finish the rotation, check the bank 2 timing notches. we want to get them perfectly lined up.
once they're lined up, verify we're near TDC EXHAUST. look at the end of the intake cam, the notch should point INWARD like this:
once you've verified this & bank 2's camshaft is lined up properly, put TWO (this is important) match marks on the bank 2 scavenge pump. we do this because we don't want to get the scavenge pumps mixed up. it's possible to install them upside down & they won't work. by placing two match marks on bank 2's scavenge pump, we can both line it up AND identify which bank it goes into just in case we get confused.....
now, pull the bank 2 scavenge pump and LOOSEN the sprocket bolts. rotate the engine to TDC and tighten the bolts.
now rotate the engine three full rotations to TDC and verify cam timing on bank 1. rotate another 360 degrees and verify cam timing on bank 2.
if all is well, we can begin reassemlby.
first, we are going to remove the cam sprocket bolts ONE AT A TIME, apply loctite, and torque to spec (10.5 ft-lb + 10% to account for loctite = 11.5 ft-lb).
BE CAREFUL, DO NOT DROP A BOLT INTO THE ENGINE.
once the cam sprockets are installed, replace the scavenge pumps with new o-rings (lube w/ engine oil first!). install new microencapsulated bolts, and torque to spec (8.5 ft-lb).
tap in new green cam covers with a hammer. no need to add sealant.
you are now done! relax & finish reassembly. drive your car
2004 Porsche Boxster S
1966 VW Bug/Type 1
1999 Harley-Davidson FLHTC
Future Volksrod
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