Commando

I was just about to put in a new cam earlier today and thought I was close to TDC but there seems to be no mark on the cam sprocket. I didn't want to screw anything up, if anyone has a picture of what the stock sprockets are supposed to look at TDC. There is a hole in the sprocket, and some other marks, but the sprocket could be in backwards. Before I continue I want to find some more info. Any info would be appreciated, Thanks.

440roadrunner

Get on Google. At the top, select "Images"
Then search with terms like
440, "timing chain"

Here's a Cloyes set that has 3 crank slots for advance/retard installation
http://www.coopofdoom.net/images/engine/IM000812.JPG
A "stocker" will have just one crank key. See the little circle on the large sprocket? I've never seen a stock type drive with no mark,
Where did you buy it?
What brand is it?
"There's a hole in the sprocket" what does this mean? Where is the hole? Are you talking about near the center, or out near the rim? If the hole is out near the outside, then the hole is probably the mark.

Here's a picture right out of my beat up old '70 shop manual. by the way you kids working on this stuff should REALLY get yourself something that covers this kind of stuff. This picture is of the horrid fiber sprocket--don't ever use them, but the timing marks line up the same.
To troubleshoot your problem, notice the following: On the cam, notice the position of the key just sticking out from the washer, about 4PM postion. Notice just under the white line that there's a "nub" for a mark. Some sprockets will have a small punch, counterdrill, or a circle. Notice that the crankshaft key is about 1PM or 2PM. Notice that the mark, which you can't see, puts the crank "tooth" lined up with a "valley" between teeth on the top sprocket.
THERE IS NOT "almost" TDC it should be exact!!


Maybe your sprocket was defective and was never marked, or is very faint. Maybe it's just a cheap *** import. I don't know. I've installed a lot of cam drives, and have never found one without a mark.
Now---a couple of other comments. The way that a BB Mopar is built, you can install the cam, drive, and then put the distributor right in there. Here's a shocker. MOST TIMING SETS do NOT line the engine up for "No. 1 ready to fire." They usually line the engine up for "No. 6 ready to fire." What this means is, that if you install the set as shown in the picture--which IS CORRECT-- What you want to do is wait 'til you get the balancer installed, and rotate the engine one turn. Check the no1 valves, or check for compression on no1. I think you'll find that you need to rotate the engine one turn to get on the power stroke--and THEN put your distributor in for no 1.
You CAN ALSO install as shown--and then just install the distributor pointing no no6 instead.
There ARE other ways to install a cam. You can use what is known as a "degree wheel" or you can check for "split overlap" Google those terms, you'll learn a lot. Split overlap is on the "opposite" rotation from the power stroke. One valve is opening, the other is closing, and as one lifter is rising, and the other going down, there is a point where they are at equal height. This is known as "split overlap" and back in the day, used to be a "check point" for installing camshafts. However, modern camshaft development has led to cams with different characteristics, and "split overlap" is no longer the "holy grail" that it used to be.

Here's some light reading from Isky

http://www.iskycams.com/degreeing.html

http://www.iskycams.com/camshaft.html

Commando

Thanks, I think I was just searching the wrong terms. The sprocket I was talking about is original and the hole is near the center. I do have a book that addresses a lot of this, its just too detailed or only applicable to certain setups. I will rotate the engine so that the keyway is at about the one to two position, the mark on the crank sprocket and see is there is a mark, maybe the dye was wearing out. I do not plan to put it back on as I have a replacement that is designed for my cam.

Commando

I took another look today when I pulled the cam out, and there is a another whole in the sprocket close to the outside, and TDC is when both sprockets have their mark at 12 o'clock, if I have the marks pointing to each other the 6th plug would fire. Someone else posted that this occurred on their engine as well, but I will replace it in the same position then rather adjust it to the way I would think it should be. Thanks again.

68GTX440

You probably already have things bolted back up, but if not, you may find the following information of some help when installing aftermarket cams and timing gears within your old mopar.

https://b4c8f51e-a-62cb3a1a-s-sites....attredirects=0

moparted

post was over 5 years ago????????