Timing

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M.smith

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Just installed new timing chain & gears on my 71 valiant with a 225 all stock, with 503,000 miles never been rebuilt been using this car as a daily driver for 40 yr's or so. Anyway I got the dots on the gears all lined up perfect and everything ,she started right up but when I put a timing light on it it's way advanced, turning the distributor only gets it close to the timing marks and is not smooth having it way advanced runs pretty smooth like 30 degrees, I have always ran it 10 to 12 degrees . What happened?
 
I think what J Glenn is getting at, is that it is possible for the outside ring of the damper to slip out of position/move; which would then cause your mark to be in the wrong position.
 
When was the last time, prior to replacing the chain, you checked your timing? Also, you mentioned your dots were lined up, but was there any slack in the chain, on one side or another, or both? And yes, it is possible to get a new chain with slack in it.
 
Of course it's advanced LOL. The timing chain was worn, RETARDING the cam, and someone adjusted the timing to compensate. At least that's one cause. Other than that----see above

Check damper mark accuracy and make certain the mechanical advance in the distributor is not "stuck"
 
^^^^^ What 67Dart273 said. + because of wear could be the distributor was moved a tooth
Also there is a plate with a bolt at the bottom of the distributor(not the one at the block) that gives further adjustment.
MoparLeo makes a very good point.
 
If it runs, the distributor cannot be 180* out.
If it was out more than a few degrees, and you get the bright idea to take the D out and move it one tooth, forget it! All you will do at start-up is move the D back into alignment, and have wasted your time.
There is only one way to compensate for this aberration which is to move the trigger; be it a reluctor vane, or a point cam, or the base plate. And that brings a new problem called rotor phasing.

What I want to know is what is dot-to-dot?
If you put them nose to nose, and align them on the centerline using whatever for a straightedge, then it is somewhat easy to be out a tooth.
The proper way is to put them nose to nose, then rotate them until they are both 180* out, and then put them on the straightedge. This will get you about 6 more inches of accuracy.
I suggest you check to see where your split-overlap is.

BTW
occasionally, when you slip the cam sprocket over the nose, it might want to spit the key out. If you have difficulty during the install, this is a tip-off. If it happened to you, then the only thing keeping the cam sprocket from slipping, is the torque of the retaining bolt, which actually should be enough...... but obviously there is no way to tell where the cam-timing ended up at. Again, checking split-overlap is the fastest/easiest way to tell if you're in trouble.
 
Last edited:
503,000 miles & it didn't need a new cam & lifters?

If you did replace the cam & it is a 'performance' cam, it could explain why it likes a lot of initial timing.
 
The slant six has two adjustment bolts. There is the one you can see going into the block on top and there is another under the distributor. You can feel it with your hand under the distributor body at about the 10 or 11 o'clock position. It is upside down and screws into the distributor base. My guess is, it's been adjusted some to take up for slack in the chain over the years like Del said in post #9 and you're going to have to adjust it back. I would make sure everything else is in adjustment first such as the points. They should be 40-45 degrees on a dwell meter. Get those correct first and then correct the timing. Normally, getting both the top and bottom bolts in the middle of each of their slots is a good starting point.
 
AJ/FormS said:
If it runs, the distributor cannot be 180* out.
If it was out more than a few degrees, and you get the bright idea to take the D out and move it one tooth, forget it! All you will do at start-up is move the D back into alignment, and have wasted your time.
There is only one way to compensate for this aberration which is to move the trigger; be it a reluctor vane, or a point cam, or the base plate. And that brings a new problem called rotor phasing.

What I want to know is what is dot-to-dot?
If you put them nose to nose, and align them on the centerline using whatever for a straightedge, then it is somewhat easy to be out a tooth.
The proper way is to put them nose to nose, then rotate them until they are both 180* out, and then put them on the straightedge. This will get you about 6 more inches of accuracy.
I suggest you check to see where your split-overlap is.

BTW
occasionally, when you slip the cam sprocket over the nose, it might want to spit the key out. If you have difficulty during the install, this is a tip-off. If it happened to you, then the only thing keeping the cam sprocket from slipping, is the torque of the retaining bolt, which actually should be enough...... but obviously there is no way to tell where the cam-timing ended up at. Again, checking split-overlap is the fastest/easiest way to tell if you're in trouble.
Click to expand...
What?!?!?! You're clueless here.
 
So when I did mine we degreed the cam and where the timing was dead on the dots did not line up. They were in the middle of a tooth so one would have to choose which side to put it on. We tried 3 sets of gears and chains and they were all off different. I now do not trust gearsets.
 
that dot are just a basic your in the area. to be sure you need to dial it in. and drill out the cam gear and put in a busing that you can play with it . did you try and just play with distributer til it runs better?
 
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