Advancing Cam Question

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Yeah check it a degree wheel isn't really that time consuming once you know how to do it and have all the equipment etc.
 
Here's the bottom line:

-I did it w/o a wheel and indicator because I installed the cam, when I assembled the engine, several years ago, and checked it with a wheel and indicator then.

-Because I knew that it was at 108, I just moved it from the "0" to the "4*" Advanced keyway on the crank gear.

-As a result, "0" 0n the balancer moved 4*, as it should have.

-The problem is; it moved the wrong way. When TDC comes up, the cam hasn't gotten there yet. The cam should have gotten to, and passed TDC before the piston got there. Thus, 4* retarded, instead of advanced. That's the best I know how to explain this.

-The crank gear must be marked incorrectly. It is now 4* retarded. Again, I installed the crank gear on the 4* Advanced keyway, and the cam is 4* retarded.

I said I was done with it, but I'll probably take it apart again. :rolleyes::(


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Why would the damper move at all?

You’re moving the camshaft in relation to the crank.

Edit-
Here's how I checked the accuracy of the 4* advance:
With it at TDC, I installed the chain in the 4* advanced position. and moved the crank (without moving the cam), until the gears and chain went on. I temp installed the timing cover and put the damper on far enough to be sure it was on the key. The timing mark moved 4* from TDC.
Click to expand...

Got it.

It appears you’ve figured out that your test proved you installed the cam retarded.
 
Last edited:
PRH said:
Why would the damper move at all?

You’re moving the camshaft in relation to the crank.
Click to expand...


If the key ways are in the crank gear he’s turning the crank, not the cam.

That’s why I said he needed to think in terms of retarding the crank, because that’s what he’s doing to get the ICL where he wants it.
 
PRH said:
He’s not using offset keys, he’s using a timing set with a 3-way gear.
Click to expand...


3 key ways on the crank gear right? If so, that’s retarding the crank to get the ICL where he wanted it.

Except he went the wrong way and advanced the crank. Which made the ICL even more retarded.
 
So I just did it again. I had to find out what's going on.

MAJOR SCREWUP! In my attempt to advance the cam 4* (to 104), I put it together a TOOTH OFF! I've been doing this stuff off and on for 50 years (I'm 65). I've never done this before! I've had retina and depth perception issues the last few years, but that's no excuse! I should've gotten it right.

My apologies to all you guys for chasing a problem that I created!

So the crank gear is marked correctly. Putting it a tooth off retarded the cam. I'm surprised it ran, and not that badly either.

Here's (once again) the comp test installed at 108*: (Both tests with warm engine and throttle open.)

1) 180
2) 170
3) 185
4) 185
5) 170
6) 180
7) 170
8) 170

And now with it at 104*:

1) 185
2) 200
3) 190
4) 220
5) 170
6) 175
7) 180
8) 200

Just took it for a 15 mile drive, and it is more responsive, idle's a bit better (I had to lower it a bit), and pulls more smoothly. No pinging, and like before, it turns over when I kill the ignition (Not needed every time.) I wouldn't want this cam in a daily, but it's fine for how this car gets used. And again, it came with all of the stuff that was in the truck I bought, and I didn't want to buy stuff I already had.

I hope to get to the track in September or October. It may not run any quicker, but I'm curious as to whether or not this helps it pull down track. Cam advance and 2" taller tires will be the only big changes.

Thanks for all the help and advice.
 
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