knocking sound on newly built motor

[TheProfessor]

hey guys i have a knocking sound comming from my newly built motor
my mechanic used a stethescope and said it might be the cam walking back and forth in the block
it is loudest in the back of the motor near where the cam drives the oil pump
it only makes the sound after warmed up and from idle to 1500 rpms only
i have a 3.1 rebuilt with performanch parts from jbody performance
including a crane 260 cam
does anyone have any idea what is going on
its under warrantee so i need to figure out what is is so i can get ti taken care of

[TheProfessor]

oh yeah and also even when warmed up and everything it still comes and goes randomly

[TheProfessor]

um why does it say gerbil bait under my name

[gpse3400]

You said you had a crane 260 cam? Any crane cam for the flat tappet 60 V6 makes some noise. A steady clacking. Thats because Crane uses a fast action design ont he cam so it just snaps the valvetrain into motion. If you get a cam from Comp cams then the engine is fairly silent, but you don't get as much from them. To make things alittle better, get the rocker studs and nuts from a GEN 1 engine and you can set the preload on the lifter(providing you do not have custom pushrods or GEN1 setup. That will help with the noise a touch somwhat, also with the power. Crane cams for these engine are nosiey. But it's nothing to worry about.

[Justin]

small block chevy engines have an optional cam button that you can stick on the front of the cam to prevent the cam from walking. I've never been into a 60* far enough to know if it would work on one of these or not, but it's something to think about.

[geoffinbc]

Is it intermitnant I would say it is the cam moving. Did you mess with the back cover of the camshaft? Do you have new timing gear installed?

[TheProfessor]

the timing cover was machined in order to fit the double roller timing gears

[wiccanferret]

um why does it say gerbil bait under my name

Look behind you. See that bit of dust? That's a ruse. He's hiding behind it. Run away....run away....

[TheProfessor]

what???

[wiccanferret]

what???

Lol...the gerbil?

[SappySE107]

You will regret that double roller in 50k miles. I bet your powerband raises in RPM later on, with less low end.

Can't really help with the noise unless I heard it.

[TheProfessor]

the low end is great actually

[SappySE107]

has it been 50k miles already?

[TheProfessor]

oh no i misunderstood you
why does the power band change

[brian89gp]

Timing chain stretches retarding the timing slightly to the cam which in effect moves your powerband up.