Hey, I've got a double roller timing chain from melling i believe got just a few thousand miles on it. At present, I just swapped my cam, and when i bolted the timing chain back up, there's some slack in it, fresh rebuild going on a couple thousand miles (maybe 4000 at most) and i wanted more power so i put in a newer lunati cam grind....

It's a 350 bored .030 compression at 9.34-1 cranking is 165 psi (yea the cam has a pretty late closing intake valve), all the parts checked out fine on the topside...however...

If i remember correctly, that chain is supposed to be tight, and it's currently got a good couple degrees of play.

is it just a case of pos defective part? that's what i'm banking on, but then who do i go through for a new double roller timing chain?

thanks for the input

 

I would suggest degreeing the cam to determine the play in the timing chain and remainder of the engine setup.

If I was to give you a visual, the chain should deflect about an 1/8" - 1/4" when applying pressure between the gears.

 

hmm, okay, I'll head into the garage and check that, I dont think it was deflecting a full 1/4", mainly i just noticed it was deflecting and got worried cuz i didnt remember any deflection.

thanks man

 

Chains always stretch some in use, even if it's only for a short time. Cheap chains stretch like salt water taffy, higher quality chains stretch a lot less. Pre-lubing the chain before you install it helps reduce the stretch- lots of it happens when you first fire up a fresh motor.

 

You know, chain stretch was one of the things I was thinking about when I degreed my new cam in and found it to be 2 deg retarded. I installed a 2 degree offset crank key and then found that it degreed in at 1 deg advanced ( ). Anyway, I left it at that because I figured that as the chain stretched over time it would tend to retard the cam timing and bring it closer to the design intake centerline. Does that seem reasonable?