Mopar 440 Timing Chain ?????

[65ny]

When replacing the timing chain on a Mopar RB, are the dots on the crank sprocket and cam sprocket supposed to be at 12 o'clock and 6 o'clock, both at 12...or what? I would have just put the new one back just like the old one came off, but I replaced the cam too. I think I did it correctly, but now I am second guessing myself.....

[techinspector1]

See post 2 here....
http://www.moparforums.com/forums/f1...sprockets-606/

[vara4]

I use to run big block Mopars back some years ago.
I've bought dual roller timming chains and never had one look like the one in
Techs web site. Mine dots usally line up, and I got them with top dead
center, advanced a couple degrees and retarded a couple degrees.
So they had tree differant settings.
If the dots didn't line up I was calling my buddy with his degreeing wheel.
Then we would check the cam to make sure it was right.
I had a cam that was not right and used a braker bar to turn the engine over
and bent a valve, good thing I didn't try to start it.
If in you think some thing is not right, degree that cam and be sure.
Kurt

[techinspector1]

Good advice Kurt.

[Mike P]

".....are the dots on the crank sprocket and cam sprocket supposed to be at 12 o'clock and 6 o'clock, both at 12...."

It really doesn't matter, although most books recommend that the marks be at 6 and 12 to make it easier to insure the chain doesn’t get installed a tooth off.

The cam turns at 1/2 crank speed. In other words if you install the chain with he dots at 6 and 12 and turn the crank 1 complete turn the marks will be at 12 and 12, one more turn and it will be back at 6 and 12.

Turning the engine over 2 revolutions and rechecking the marks at what ever location is the final step prior to reassembly.

Just a side note…..having the marks at 6 and 12 makes the engine ready to fire on # 6 cylinder and at 12 and 12 number 1. As chances are that the crank will get turned during the reassembly, I normally pull # 1 plug put my finger over the hole until I fell compression then rotate then engine until the timing marks line up before I reinstall the intermediate and distributor.

[65ny]

[QUOTE=Mike P
Just a side note…..having the marks at 6 and 12 makes the engine ready to fire on # 6 cylinder and at 12 and 12 number 1. As chances are that the crank will get turned during the reassembly, I normally pull # 1 plug put my finger over the hole until I fell compression then rotate then engine until the timing marks line up before I reinstall the intermediate and distributor.[/QUOTE]


Thanks to all. I was SURE that I was going crazy. My mind was telling me that if the marks were at 6/12, the # 1 cylinder was ready to fire, but the #1 cyl. was ready to fire when the marks were at 12/12. (finger in the hole method ) So......I suppose I had it correct the first time, but my own brain was getting in the way. (happens all too often)
Thanks again for bringing me back to reality.