Rod knock or Weak Motor Mount ?

[commando1]

Comp cams are notorious for wiping out lobes especially on the Extreme Energy series. I have been running a zinc addative to try to prevent that problem from happening.

I experienced that and I have heard countless personal experience with theirs in their 440's.
I went by the bible for new engine break-in and yet it still happened.
Never will again, though. No more Comp Cam stuff ever for me.

 

[Ripinator]

I experienced that and I have heard countless personal experience with theirs in their 440's.
I went by the bible for new engine break-in and yet it still happened.
Never will again, though. No more Comp Cam stuff ever for me.

The more I hear about Mopar purple cams, the more they seem to be the way to go. . . especially with C-Bodies.

 

[65Fury440]

I experienced that and I have heard countless personal experience with theirs in their 440's.
I went by the bible for new engine break-in and yet it still happened.
Never will again, though. No more Comp Cam stuff ever for me.

X2

 

[rumpfox]

you have a dead cyl. that is why all the eng. shaking and the knock you hear is hydrolic knock cause the cyl. is full of fuel and comp. and has no where to go. i'd say an ehx. valve has stopped working.

 

[Landyacht]

Its confirmed ! Pulled the intake and found a worn lobe on the intake side of the #4 cylinder. I have a .509 lift purple cam on the way. Summit listed two different cams with the same lift and duration . One has a 108 degree lobe separation the other 114 degrees. I went with the 114 degrees lobe separation. Not quite sure if I made the right call on that one. Also have an M1 intake on its way.

 

[Ripinator]

Its confirmed ! Pulled the intake and found a worn lobe on the intake side of the #4 cylinder. I have a .509 lift purple cam on the way. Summit listed two different cams with the same lift and duration . One has a 108 degree lobe separation the other 114 degrees. I went with the 114 degrees lobe separation. Not quite sure if I made the right call on that one. Also have an M1 intake on its way.

I hope you also ordered all new lifters with that cam. . .

 

[70bigblockdodge]

Crap wish I would have seen this earlier would have made the suggestion for the .528 solid cam it will actually idle better.

 

[Snotty]

Way too late now, but I had a similar concern with the 413 that was in the '62 New Yorker I owned. Start the motor and hear the rods bang, shut it off and they would do so as well! Accelerate the motor and hear them, back it off and hear them. I just KNEW they were ready to let go.

Turned out to be a bad harmonic balancer. Found it by accident while checking the timing. Put on a new one and the problem was gone.

 

[Landyacht]

Problem solved after all this time. It turned out to be a loose flex plate.

 

[furyus 67]

At least it lead to finding the other issues lol! Running good now?

 

[Landyacht]

At least it lead to finding the other issues lol! Running good now?

No more knock cruising at 2500 RPM. Sounds the way it should. When I installed the flexplate the first time I didn't use a torque wrench to tighten the bolts to the exact specification(55lbs) which turned out to be a big mistake.