Resetting the Cams

Mountainman45 · Post by **Mountainman45** » 04 Jun 2020, 18:18

I'm currently rebuilding a 2003 V70 T5 head (B5234T3) and, foolishly, I removed both sprockets from each cam when I was uninstalling the cams and cam cover, rather than just lift up the cams and sprockets as one piece. I only have exhaust VVT so I can clearly differentiate between those Intake and Exhaust. My confusion comes in when I have to reinstall the cams and sprockets. I no longer know which way to rotate and bolt up the cams to match up the cams and crank to find TDC. I'm happy to answer any questions i just really need advice!

Post by **abscate** » 04 Jun 2020, 19:30

There are no TDC marks, just clearance marks , on either cams or crank

On a VVT CAR, the cams and sprockets have to be set by indexing the rear of the cams with a cam tool.

It needs to be correct to within 4 degrees of rotation of the cam, so eyeballing it probably won’t work

Mountainman45 · Post by **Mountainman45** » 04 Jun 2020, 19:47

Where do I find clearance marks?

Post by **SuperHerman** » 04 Jun 2020, 19:51

Front of the cam has the VVT and/or gear - rear of cams have slots. The slots are aligned with the head seam as I recall. One of the cams is above and one is below - the alignment is horizontal or parallel - not verticle or 90 degrees.

If you have cam tools your task will be easy as the tools will only slide in if the slot is orientated correctly. If you don't have tools it can be done, but not so easy. Some people make a holding tool out of angle iron.

I suggest you do some searching on the forum as there are plenty of right ups with pictures of how the slots on the rear have to be aligned. Once you figure this out just lay the cam as close to this position as possible for each side and install the cam cover. Once this is done you can find tune the slots so they are dead on. The few degrees of movement will not be an issue.

Before doing this make sure the crank is at the correct timing mark - it can only be correct in one place. Same for the cams - if all three are at their marks you are good. You can fine tune the cams the few needed degrees in either direction. Everything changes once the timing belt is installed as the system is tied together.

So - research which side of the seam your cam slot needs to sit at and put it as close to that point for each side - again the intake and exhaust cam, as I recall are different with respect to which side of the seam you want. It will make sense once you see the pictures people have posted.

Post by **SuperHerman** » 04 Jun 2020, 20:00

viewtopic.php?f=1&t=26864

See here - it shows much of what you ask.

Post by **abscate** » 05 Jun 2020, 04:55

Since the engine is angled the cam slots will not be parallel to ground , but parallel to the seam on the cylinder head.

FREEBUSINESSES · Post by **FREEBUSINESSES** » 13 Nov 2020, 12:20

Technically, the notches are not exactly parallel to the head to valve cover lines, they are a little off, and TDC is not how you set timing. Number one piston should be just before TDC to be in proper time to cams. When you have cam tool set, you will see that the slots are not parallel to seams. For what it is worth for others seeking advice on setting timing.

Post by **abscate** » 13 Nov 2020, 19:39

The off seam angle error is less than the tooth spacing in the timing belt so it isn’t really relevant. On a VVT car you have get both the initial set and then the VVT hub(s) in the right position(s) or it will code