Degreeing cams

A poor substitute for proper timing methodology.

Measuring max lift and hoping it is the lobe center when the factory method (lift at overlap) is actually easier. I forgot, those guys in Maranello are idiots and have no idea what they are doing so their method should just be ignored.

Some dips##t do it yourselfer always knows better.

 

103 degrees inlet lobe centreline is calculated as follows:
Inlet opening at 16 BTDC (WSM info)
Inlet Closing at 42 ABDC (WSM info)
difference TDC and BDC =180 (duh)
So total duration is 16 + 42 + 180 =238
Middle is half of the duration, so 238/2=119
As Inlet opening it is noted in degrees BTDC, and the middle is ATDC , we want to know in ATDC degrees, so we have to distract 16.
119 - 16 = 103 ATDC
Same method for lobe centre line exhaust.

 

You are crossing a line here, a pity.
I have never said that the centre lobe method is better than the valve lift method. As frankly I have no clue if that is so. I know what the WSM says, and of course Ferrari is right that the valve lift method is correct. But do they say that any other method is for d*psh*ts? No sir.
I appreciate your time and help, but name calling is not really helping.

 

I wasn't talking about you.

Whoever told you to do it that way was off base.

If you had read the book and done it their way it would have been done long ago. There exists no reason not to have done so.

Instead you chose to reinvent the wheel and by happenstance only you have not bent some valves......hopefully.

 

Robbe, measure valve lift per the WSM - it's really that simple. Be sure when you measure the lifter that the indicator is dead nuts parallel to the lifter axis.

 

Ok, will do that tomorrow as you all keep saying that, so I better listen. I had very little time this evening, so I just checked it by the simple centre lobe method to see in what ballpark it is.
The marks are 26 degrees off on the cam, and the position of the centre lobe line was off 27 degrees . I did not have time to check it a few times, but it strenghtens me in the theory that my cam on the 1-4 is indeed some 26 - 27 degrees off.
To be continued tomorrow , work then done totally by the book (WSM)

 

I hope you are not slapping valves into the pistons as you rotate the crank...

 

Fatbillybob and the others that have contributed,
thank you for taking the time to help.
I will take the 355WSM and do it all over again, hopefully already tonight. Will double check those results by using the other methods as well. Should give nearly the same readings, otherwise I will have to start over. But I do not expect that as I have consistent readings sofar.
By the way, the engine is still on its old belts, I am only checking if it needs degreeing.
As it ran before I pulled the engine, I am sure that the valves are not hitting the pistons...
Before I take the old belts off to degree any cam, I must be 100% sure what is wrong, me or the car. And just setting up to factory marks is always a possibility, but indeed it is better to properly degree them, as the factory did.
Thanks for the delrin mallet suggestion, will try to buy one over here.

In the mean time, could someone please try to answer this question: When one cambelt has jumped a tooth and the other has not, would a 355 still run more or less normal? (on some cars you do not even really notice it (some loss in power), on others they run like sh*t.)
As that would explain this whole thing with misaligned marks only on bank 1-4, but not on 5-8 (as those are perfectly aligned when you look at the Assemblers marks on the REAR of the cam, just checked)
If I was not able to decently find TDC on nr 1, then the markings wouldn't have lined up perfectly on 5-8...

 

No, it will run like **** and a slowdown light will eventually come on when that bank will be shut down and you can barely drive up the flatbed tow truck.

 

Ok, went to work yesterday. I printed out the WSM parts that describe the valve lift technique.
As I read that on the rear of the cams there are Assemblers marks stamped into it, and on my right bank the exhaust cam lines up 100%, I best try it first here.
Connected the dial indicator to the bucket, set dial to 0 and turned CW till I got 2.41 mm lift. Degree wheel shows 1 degree. Should be TDC, but close enough. Great!
To verify I used the lobe centreline method, and that came off 2 degrees. Also close enough I think, as that method is less precise. So bank 5-8 intake is ok.
Then the exhaust. To be honest, I did not completely understand the WSM on that, should it be lift or remaining lift? As it has to be on a closing action, and then you can only positively measure remaining lift when started at 0. Never mind, the centre lobe method also showed 2degrees off, and this cam has 100% lined up markings on the rear.
So no worries here.
Now I know that my TDC findings are correct, time to turn to the troublesome bank of nr 1-4.
Rear marks do not line up, front marks do not line up. So what is the result with the valve lift method on the intake cam: Instead of seeing TDC on the degree wheel at 2.41 mm lift, I see that it is 16 degrees off (compared to TDC). Ok, so it is off, but that is not that much as I feared.
Centre lobe method, now it is 28 degrees off. Hmmm.
Ok, tonight do the 1-4 all over again until I get consistent readings on 1-4. Consistent readings off that is...
My conclusion sofar is that as I get factory spec results on bank 5-8, my methods and routine are most likely correct. And if that is so, the 1-4 bank is not near factory spec and should be corrected. A lot. To be continued.
To moderators, I can imagine that this is polluting an excellent posting, my apologies, maybe you can split it into a new thread?

 

Just keep one thing in mind: The lifter travel does not equal valve travel. The lifter will stoke some amount until going solid, which at that point it will start to move the valve.

 

Let's not confuse the issue. This has noting to do with setting the timing. Timing is based on, as per the WSM, movement of the lifter (bucket, tappet, or what ever other name you choose to call it).

 

Ok a simple question, when you are at TDC for #1, where are your cam assembly marks for all 4 cams? Sorry if u have already posted this but I couldn't find it.


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Remember Im not a pro. One other simple thing to remember, turning the motor anti clockwise is ok when finding TDC (piston rise). Because of tensioniers and slack that is taken up with backward rotation of engine, it's not ok to spin the motor backwards when aligning cam marks, unless you overshoot the marks anti clockwise (I use at least 90degrees. No data on this, just me), then proceed clockwise again to your target. Also I personally always check and re-check cam timing without any anti clockwise engine rotation, after a couple of full clockwise rotations. Remember Im not a pro.


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All four cams will be lined up with the first cam cap notches with #1 at TDC.

 

That's my point. Is this in fact true for him? If so then both banks should be close and he couldn't have things as muffed up as he thinks (assuming the original assembly was correct whichnis a whole other can of worms).


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FBB - I know you are very experienced and you can, and have degreed circles around me, but I had this problem with my 360 with those rear marks. I thought they may not have even been there. Despite cameras, and lights I couldn't see those freekin marks. The cam cap had a easily visible ~1mm thick mark, and the cams themselves had a scribed mark the thickness of a hair that I couldn't see because line of sight was obstructed. I ended up taking impressions of the marks with my kids play dough. Worked fantastic, and I was able to get a great look at it from the impression. I was even able to save the original positions, and compare them to those after I was done degreeing by saving my play dough impressions.


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Ok, last posting for now. Things are going well. (will report further once engine is back running in the car)
I checked and rechecked by all 3 methods , how far off both LH cams were, and it was 22-24 degrees. And as said the marks did not line up on this bank, not on the front, not on the back, on also some yellow paint on the cam pulleys did not line up. Looked like 2 to 3 teeth off.
So I loosened the tensioner, removed the old belt, turned the exhaust cam the one way and the inlet the other, et voila, all markings were in line on all fronts (while at TDC of course)
Time to verify then. Inlet valve lift at TDC is 2.43, or at 2.41 it is 1 degree off. Lobe centre line was 105 instead of 103, so close enough for now.
Exhaust cam , same story, 107 instead of 110, so only 3 degrees off. Much better!
All markings on the whole engine line up now, and all checks are ok in all sorts of ways.
I am convinced that I have rectified someone's previous service mistake with this
The only thing I now have to do is effectively degree the cams once the new belts are on.

Tried already to loosen the cam pulley bolts, but these are really stuck, and can't get them loose, not with heat and an air gun. Any ideas? Like it is rightey loosey instead of leftey loosey?

 

Impact wrench. You should have removed the cams, put them in a vise, and used impact wrench to loosen the bolts before you install them back,

 

I took the cams out, rapped an old belt around the cog and my hand and used an impact wrench.

They loosened right up.

 

If you break a cam cap - game over. Time for a new head. I would not suggest putting anything under the caps. Use cam locks to lock both together then they cannot rotate. Problem solved.