Check your cam timing

gilhuly · Post by **gilhuly** » 18 Sep 2009, 19:19

I haven't messed with this in a long time, but on a turbo you would advance the exhaust and not the intake as much. I believe I'm also about 3 degrees advanced on the exhaust and 0 on the intake with the wastegate actuator tweaked up some. My car is very responsive. I also have a tune, dp and exhaust.

Post by **hausmeister** » 19 Oct 2009, 11:37

Just a question:
If you advance the intake cam, will that not also mean less power at high rpm? So a trade off - more power at lower rpm, but not as much at high rpm?

Post by **micah861** » 19 Oct 2009, 12:20

hausmeister wrote:Just a question:
If you advance the intake cam, will that not also mean less power at high rpm? So a trade off - more power at lower rpm, but not as much at high rpm?

thats probably true, but i believe the idea, is to gain useable power, most of us do more driving at the lower end of the power band

rbodor3 · Post by **rbodor3** » 07 Nov 2009, 11:46

Good for your pre-98 vehicles, but 99 after will throw a sick code :\

Post by **djm850** » 22 Jan 2010, 12:44

This is interesting. I'm in the middle of intalling my rebuilt head. Here's the exhaust cam sprocket orientation to the cam when the opposite end slot is parallel/offest just below to the mating surface of the top half of the head (which should be timed for TDC). Unless the previous owner had cam seals replaced prior to 89k miles, this is from the factory. So, is this position advanced? BTW, the intake was dead on center.

Post by **djm850** » 22 Jan 2010, 22:11

Sorry, here's the pic.

: Exhaust sprocket Web.jpg (137.89 KiB) Viewed 4050 times

Post by **tjts1** » 25 Jan 2010, 20:56

That position looks about 3 degrees retarded to me. Check the pic in the first post in this thread. Mine was in the exact same position from the factory.

Post by **jblackburn** » 26 Jan 2010, 00:09

Anyone know if the cams on the S70's came from the factory like that, or did they change that from the 850 when they gave it the "power bump"?

I'd assume they're the same, but I was just wondering if anyone happened to know for sure

9394volvo850s · Post by **9394volvo850s** » 26 Jan 2010, 00:23

yea there all retarted on the exhaust cam. even on the 960s S70 and V70. its best set it to center at the very least. i cant tell you why Volvo set them retarded.

Post by **djm850** » 26 Jan 2010, 06:12

tjts1 wrote:That position looks about 3 degrees retarded to me. Check the pic in the first post in this thread. Mine was in the exact same position from the factory.

Remember now that the pics is with the top cylinder half upside down, so the sprocket is actually off center to the front of the car when right side up. Still retarded?

So, I should just shoot for center. Would anyone elect to advance it?

Also, this is some advice I was given by a Volvo mechanic on JustAnswer.com regarding the slots and how to set them. Discuss.

HIM: "I would use "the tool" or a similarly suited device to lock the rear cams into place. At that point leave the front bolts slightly loose, and install the belt, where the bolts end up (while the belt is under tension please) is where the front sprockets should be locked down onto.

ME: So, are you saying leave them just snug, route the belt with hand tension up and over the intake sprocket, adjust to center the belt then tighten sprocket, then across to the exhaust (under tension), adjust again to center the belt and tighten, finish routing, release tensioner, rotate crank clockwise twice, then recheck marks?

HIM: NO, I am saying fit them loosely. Install the timing belt, finding your "center tooth" on each camshaft, release the tensioner pin, THEN tighten the sprocket bolts.

Check your cam timing

Re: Check your cam timing