[Jay S]

The factory advance of 1.5* is subtracted from the lobe separation angle to find the installed intake centerline.
113.5* - 1.5* = 112 *
The installed intake centerline when you line the timing marks up like the factory setting, dot to dot” is suppose to be 112*. Which can vary, and is why it is better to degree the cam in.

You simply have no business using any of the other keys (other than the zero position) on the timing set unless you degree the cam in afterward.

[TRADERMIKE 2012]

Originally Posted by Jay S

The factory advances of 1.5* is subtracted from the lobe separation angle to find the installed intake centerline.
113.5* - 1.5* = 112 *
The installed intake centerline when you line the timing marks up like the factory setting, dot to dot” is supposed to be 112*. Which can vary, and is why it is better to degree the cam in.

You simply have no business using any of the other keys (other than the zero position) on the timing set unless you degree the cam in afterward.

You said: The factory advances of 1.5* is subtracted from the lobe separation angle to find the installed intake centerline.
113.5* - 1.5* = 112 *

Mikes reply:

Thus: 112 degrees is the Installed intake center,
(112 I c/l)

Now, I added 4 degrees to the Cam timing, show me how you would proceed please next.

In addition, I agree when I am done, I will install the degree wheel again to prove that the advanced timing is actual.

I am already planning to pull the Timing cover with the water pump attached to install the degree wheel and pull back the advanced timing to the 3rd notch that is 6 degrees at the Crank or 3 degrees at the Cam.

Now that you know the plan, please do the entire math process, the way I should be doing it, so that I can see where the difference is between our thinking.

P.S. I installed the timing Chain gears at 12 0'clock each for Pontiac @ TDC of the compression stroke.

[Jay S]

Don’t change anything until you degree the cam in and find the position ICL is at now. After that you can better determine which key to use.

[TRADERMIKE 2012]

Originally Posted by Jay S

Don’t change anything until your degree the cam in and find the position ICL is at now. After that you can better determine which key to use.

I know I am 4 notches at the Crank and at the Cam I am 4 degrees advanced plus 1.5 in built into the Cam added together I am at 113.5 - 5.5 = 108 theoretically, now I must prove it by degreeing using the .050" method on the Intake Valve. Once we know where we are truly at, we can decide where to go from there.

[400 Lemans]

It's a good thing you are going to take it back apart and check it with your degree wheel. I think you are going to find out that you are at 104 degrees advanced and not the 108 that your looking for.

[Formulajones]

As Jay is trying to explain, and as I mentioned earlier, You absolutely cannot just rely on math figures that are supplied by cam manufactures, timing chain manufactures etc.....and just toss it together expecting it to be correct.

What ever figures you're coming up with from the cam manufacture and what ever the timing set says, you can throw that out the window, none of it matters.

All that matters is what that degree wheel and dial indicator on that intake lobe tells you. 9 times out of 10 you're going to find that the ICL is not exactly what it's thought to be. There are variances and tolerances that aren't 100% when it comes to those keyways on the crank and camshaft, and also with the timing set both on the cam gear and crank gear. Even if one or the other, or both, are off a couple thou you're going to find bigger changes on that degree wheel that won't match what your cam card says or what you've been told it should be. And every time you move that crank gear to advance or retard the cam, you'll have to check it again, because what you think you moved it, I can almost guarantee you'll find it was much more or much less than what it should have been.

It's a tedious process, it's not as simple as reading a piece of paper and just lining up dots, "IF" you want to do it correctly.

Honestly I would have been more concerned with the bottom end issues that have been pointed out than I would have been with the camshaft.

[TRADERMIKE 2012]

Originally Posted by 400 Lemans

It's a good thing you are going to take it back apart and check it with your degree wheel. I think you are going to find out that you are at 104 degrees advanced and not the 108 that you're looking for.

Well, here are the new numbers for you:

(1) Advance key is at 8 degrees at the Crank and 4 degrees at the Cam. 113.5 Ic/l (1.5 + 4 = 5.5 advance),
113.5 - 5.5 = 108 degrees advance, hypothetical.

(2) Post # 299 has a math error, sorry late at night

(3) We set the Degree Wheel back up to the Engine Crank. We set the Dial indicator on the #1 cyl. @ TDC on the compression stroke.

(4) At .050", after passing to .100" and back to .050" on each of our tests we came up with these degree results:

109, 109.5, 110, 113, 115, 116, 113, 111.5, 110.5, 111.5, 111.5, 111.5, END.

(5) Supposition: The numbers range from 109 to 116, that is 8 different degree numbers. The question is: "could one surmise this is due to Dwell?"

(6) Supposition: Since 112 degrees is in the middle " is this the true TDC now, with the advance we added?"

(7) Note: 112 degrees just happens to be the "041" Cams Intake lobe centerline from the factory.

(8) Is my new ICL now 112 @ 0.050"?

(9) Note: We are using the .050" position on both sides of the Intake Lobes Cam lift to find the new Ic/l after an 8-degree key is used on the Crank Gear, this is 4 degrees at the Cam!

[Jay S]

LOL..17 pages..I don’t think anyone has put a dent in the OP’s armor, or his skills with cut and paste features…

[Jay S]

I bet if one of us would have read one of those last long posts we’d find out he got it all figured out and is driving it around.