I installed my new round of mods in the last days, including the NA intake cam, and I noticed something about cam degreeing that probably is not like most of us has initially thought.
I would like to know if other people has noticed and though about it.
Let's get started.
I only installed NA intake cam so I kept my turbo exhaust cam. I swapped the turbo intake cam sprocket to the NA intake cam even though they look exactly the same, including the notch on it seems to be in the exact same spot if I recall correctly. I did this just for extra assurance because it's easy to swap them but I'm 99,99% sure the n/a sprocket should be exactly the same.
On installation I used volvo cam locking tool (borrowed by a friend working in a volvo official shop) to put both cams at 0º.
With both cams at 0º and the sprockets installed in its normal position (with the noches facing the timing marks on the plastic cover as close as possible) and using the IPD cam timing tool I was able to check that the sprockets would indeed allow a +6 or -6 cam timing adjustment on both cams.
So far all seems normal.
Further to that and:
1. with the tension belt already fitted
2. with the tensioner pin off (so tension belt fully sat)
3. with cams' sprockets bolts still loose
4. With the notches pointing right to the timing marks on the plastic cover.
I found that:
1. The notch on the intake cam really matches 0º degrees on the IPD cam tool.
2. The notch on the exhaust cam doesn't match 0º degrees on the IPD tool. The notch matches 3º retarded on IPD tool.
Please remember that all of this was done with the volvo locking tool still in place so the cams were really at its 0º position.
Has anybody noticed this as well???
I think this is due to the factory setting for exhaust being 3º advanced (correct me if I'm wrong. I read this somewhere a few months ago) and volvo wanted the notch to be already the mark for 3º advanced -> note that if ou advance the cam 3º degrees you will match the notch with 0º on IPD tool.
So, it seems I can conclude the following:
1. IPD cam tool graduation for the exhaust seems to be in the wrong place. For the intake is correct.
2. It seems IPD thought the notch on exhaust cam would match 0º but nope. The notch means 3º degrees already advanced if no one has messed with the sprockets so far (which is unlikely in a car with more than 10 years and probably with 2 or 3 replaced timing belts).
2. IPD cam tool graduation for the exhaust should be moved 3º degrees to the right so the 0º degrees would match the notch.
3. Unless some of us had previously replaced its tension belt with the locking tool by himself (or any other work that requires to deal with this kind of stuff such as fitting a different camshaft) I think most of us was advancing or retarding its exhaust cam without knowing that we were not achieving the desired setting/degrees.
4. Probably IPD cam tool was not designed to match with the notches but only with new marks made by ourselves after setting the cams in 0º with the locking tool. However, that's not what they say on the manual of the tool...
I initially had my exhaust cam set to (supposed) 2º advanced. Well, these findings apparently show me that my exhaust cam was actually 5º degrees advanced because there is a 3º difference between the real 0º degree and the notch on the cam.
With the locking tool still in place I did a small mark on the exhaust cam sprocket where the IPD tool shows 0º. So now I know where the real 0º is on the exhaust cam.
I would like to know if I'm crazy or if someone also spotted this issue.
Feel free to give your inputs.