Arnie:

Understood about the 'removal' of variables.

As stated in my reply previously, the cam is degreed
by itself first, then double checked with the pushrod
and rocker arm set to zero lash (dummy mech lifter).

As my "mentor" once said, "the cam may be in phase,
but it's the valve reaction that matters"

He just enforced the idea to double check with all the
component to make sure the valve movement is timed
properly.

Might seem a little ****, but it made sense to me.

 

Explained that way, understood. Took care of the cam, and then turned your attention to the valve train. Sounds like a mentor that 'covers the necessary bases'.

 

One needs to have in mind, that GM engineered the opti/injectors to be in correct/accurate time when the cam dowel is indexed accurately, period! Either it is in time (indexed correctly), or it isn't. If it isn't, to a degree of inaccurate index, based on the degree of indexing error between crank and the dowel itself. *Establishing above, the scenario that the cam dowel is indexed accurately with the lobes on the cam, the cam degreeing procedure WILL also insure that the injector/opti drive dowel is positioned accurately/correctly. I'm confident GM engineers are also aware of the stackup of tolerances on the associated components of the crank to cam linkage hardware. This obviously, is the focus of the cam degreeing operation, in my posts.

*I established this scenario to keep my discussion devoid of the incorrectly ground cam variable, and resulting, more confusing, knee jerk counter measures necessary, intentionally.

BTW, I personally, have not ever witnessed a cam setup and ground. However, common sense would lead me to believe the drive dowel hole is drilled in beforehand, and thus used to index cam, for the lobe grinding operation. Barring an operator error, it is thus highly unlikely the cam lobe would be indexed incorrectly with (opti) drive dowel.

 

Ok as clear as can make it with out going to far off the path.

The Opti has NOTHING to do with the cam other then it is driven off of it by the pin.

That is what I keep trying to say but you keep relating it to the cam .

The opti NEEDS to be indexed to the crank not the cam. This is where the problem is.

WHEN you degree the cam in you are Moving the Opti from the correct position it needs to be. That position is in relation to the crank not the cam.

Technicly the Opti is driven, and indexed, off the timing set(two sprockets and a chain)not the cam. The ONLY thing the cam provides is a pin that indexes the opti to the top sprocket and hence the crank shaft.

IF you move this pin position to line the cam to the crank correctly you just moved the opti and the correct Opti to crank position has been lost.

SO this correct way to dail in a cam would be to use custom made offset cam dowel pins. That way you could position the cam correctly and NOT move the opti from its correct position

The problem here is when you move the cam to correct one problem you move the opti the oppisit direction and cause another.

BTW if you are degreeing a cam it is because the Pin is not where you would like it in relation the the lobes on the cam and you are moving them to a position you would to match the crank position. Basic math

Does this clear it up any?

 

Ok this is what im am going to do....Slot the Dist. bolts and make a pointer set at TDC off of the balancer. use a timing light to set the timing... That should take care of it. I will post results.

 

I have no clue, as to how you figure the dowel, hence the opti, is located/indexed correctly to begin with. Ellis, we need to agree that we disagree, and are about 180* apart. Neither of us is making any headway with the other. In the end, one of us has to be incorrect. Take care.

 

I guess we can agree on that. To me it is some thing that is always so. Then again I am just a mechanic

I think the only way I could show you was to be in the same room and go over each part and the manufacturing process of each one to explain.

HEY It is snowing out side...Kool!

 

The way I understand it I don't see anything to argue about, retard vale timing with timing chain & advance your ignition to compensate a few degrees, fuel sync to crank isn't important IMHO.