knocking sound!!!

[CUDA383]

I just installed a 440 in my 70 cuda. I put a .509 cam shaft in, and heavy single spring with damper valve springs. It has six pack rods and stock 452 heads. Well my problem is i have this awful knowcking sound. I have changed the lifters and cam to a .454 and i have changed the pushrods and rocker arms. And i still have the knocking sound. I have also check my valve springs and they dont bottom out on the valve guides. So any help would be great because i am leaving for the marines and i need it running good before i leave. My next move is to check the valves, they might be bent. Any one have any experience in a .509 cam and the clearance. I am thinking that it was to much lift and made my pistons smack the valves which caused the valves to be bend. Which could be my knocking sound if the valves cant close all the way. But this is just a guess. Please help!!!!

I have always wanted a 440 in my cuda!!
Now i am having second thoughts!

Cuda383         (Now Cuda 440 KNOCKING)

[Chryco Psycho]

You do not specify which piston you have but the .509 cam should not hit a piston unless you have 12 : 1 comp , are you getting oil pressure ??, is the knock a taping sound or a thud ?? does the knock change as you accerate or decelerate the engine or is it consistant ??

[whitesatinmopar]

I can't beleive it's a piston/valve problem either except for possibly the high ratio like chryo psycho mentioned. I put that cam in a 383 mag. 4 spd. car and it bent the hell out of a stock push rod, so bad in fact when I tore it down the lifter was up in the valley, you better belive it, just call me lucky, guess what that pushrod would have done wrapped around the cam lobe? OUCH! But that didn' cause a knocking sound.

[CUDA383]

the pistons are stock flat tops. It sounds like the rocker arm is clattering. Another idea was brought to me, maybe the push rods are to long. I think someone might have deck it. But i am not sure. I am going to check today.
I wil get back to you guys.
Thanks
CUDA383

[CUDA383]

yes it changes with accelaration. It gets lounder!!