Just when I thought I understood A timing...

forever4 said:
I still don't see a mark on any of the teeth on the crank gear,
But I think it is meshed correct now.....right????

The more I look at that crank gear, the more I think it has the keyway also broached about 5 degrees out of position.

I also noticed that Les Andrews diagram is off-angle and does not match the genuine Ford illustration posted on my web page.
Click to expand...

In the first picture in my last post you will see a tiny whitish spec on the crank gear that lines up with the cam gear dimple, which is 3 teeth off from the proper timing.

On the second picture that same mark on the crank gear is 4 teeth to the left.
Something mighty fishy going on here. :confused:

I'd pull the oil slinger and check the key.
 
Let me throw in another perspective. The gear may be marked correctly but the key way was machined in the wrong spot. If that is the case you may still be a few degrees off by meshing with the correct tooth. Unless measured with a degree wheel you can't be sure. I'd just put a correctly marked gear on there and toss that one.
 
forever4 said:
I still don't see a mark on any of the teeth on the crank gear,
But I think it is meshed correct now.....right????

The more I look at that crank gear, the more I think it has the keyway also broached about 5 degrees out of position.

I also noticed that Les Andrews diagram is off-angle and does not match the genuine Ford illustration posted on my web page.
Click to expand...

Some of the repo gears from the 70ts were off. That may be one of them.
 
You guys just can't let a good "saga" go, can you?:D:D
I have to admit that not taking the pulley and slinger off to make sure everything is OK down there is bothering me a bit. It's not in following my "check everything" mentality. So I will take it apart and take a look. I've added a red "O" around the only mark on the crank gear, it is hard to photograph but very easily seen in person. It looks like a single strike with a punch. I do think it is properly timed now because I ran the crank around to TDC on #1 (valves closed) and it aligned the ignition timing mark in the cover perfectly.
 

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Whatever you do Don't get #1 to tdc and then check for overlap on #4.
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Yes, the slinger needs to come off, and I would also use a small dental type mirror to look at the backside of the gear while you spin the crankshaft around to see if any factory timing marks are present. That small nick sure doesn't look like anything more than someone's punch mark, or something dropped against the gear and left a mark. But, the mystery still remains about how 3 teeth off became 4 teeth off.
 
I think the confusion on 3 or 4 teeth off is just the different camera angles.

I like the "mirror on the backside of the gear" idea. Could it be some previous owner turned the crank gear around during the latest "rebuild" to use the other side of the crank gear tooth faces against the cam gear? He carefully marked the back side of the same gear tooth that was factory marked to insure he used the same tooth to line up with the cam gear. However, due to the helical cut of the gear that would be the wrong thing to do.
 
Does it matter if it's on backwards? I suppose the key-way could be damaged, wrong size, etc. I hear the crank gear is very hard to remove, I don't want to take it off if I don't have to.
 
Art Newland said:
Does it matter if it's on backwards? I suppose the key-way could be damaged, wrong size, etc. I hear the crank gear is very hard to remove, I don't want to take it off if I don't have to.
Click to expand...

It could throw the cam to crank timing off by a few degrees, depending on how the gear teeth line up with the keyway.

I do agree with not wanting to remove the gear, if you don't need to, as they can be extremely tight.
 
This thread won't die!!!
There is something else that has been bothering me about Art's pictures in post #1. In the first pic, the piston is at (or close to ) TDC, yet the exhaust valve is open. That shouldn't happen till the piston is near the bottom of its stroke, a whole half a turn from where is it in the pic and certainly a lot more than either 3 or 4 teeth. Am I missing something or is there more?:eek:
Not that this explains the open valve but if the marked tooth on the crank gear is out in relation to the key, who is to say that it is out by a whole number of teeth. The key could have been cut, say, 3 1/2 teeth out. That might explain the 3-4 teeth issue.
Another (but unlikely) issue that hasn't been mentioned is "Is the key slot cut in the right place in the crankshaft?"
As they say, the thlot pickens!
 
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I think I would take the crank gear off and hang it on the wall as a reminder of what can bite you in the butt. Then, get one that at least has a chance of being right and marked right off the bat.
 
Has anyone ever seen a picture of what the valves and pistons are doing when the cam timing marks are aligned?
 
Why not tack the timing gear cover on lightly and drop the pin in as you would to time the ignition and see where the piston and valves are? And then crank till the marks align and give us a report.
 
I just checked a 1928 crankshaft that has a 2 piece aluminum pulley and slinger still bolted in place. I don't see any timing mark on either side of the gear, but maybe it's lower and covered by the slinger.

The keyway, and number 1 and 4 crank throws are all at TDC together.
Wish I could find my new crank gear to check that also.
 
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