Annoying Engine tick- push rods too short?

[timmycharger]

I refreshed my 440 about a year and a half ago, changing the bearings, gaskets, rings as well as swapping out the stock iron heads to Edelbrock RPM.  The engine runs very strong, plenty of power, super responsive.  with the Mopar 484 purple cam, vacuum is at 10.5 at idle, 60PSI warm oil pressure. I run 10/30 Castrol GTX oil with STP zinc additive.  I have had a loud tick that follows the engine speed that sounds like valve train to me that has been present since the rebuild.

I am running a hydraulic mopar 484 purple cam, hughes 1.6 roller rockers with 3/8 push rods. this is the exact setup that I removed from this engine 15 years ago when it ran before the rebuild.  The cam was still in great shape so I re used it along with the lifters.

Thinking it was the rockers, I adjusted them in and out a half turn, did nothing.  I took them completely out of the equation by putting in a bone stock stamped rocker set with stock pushrods, the noise was still there, no change.  I then noticed some dents in the baffle of my valve covers so I clearanced them further with a ball peen hammer, noise still there.


I then swapped out the used lifters with a brand new set of comp cams lifters and although the noise seems slightly quieter, it is still there.  While doing the swap, I checked all of the push rods for straightness on a steel surface, all good, no marks on them at all.

I am at a loss as to the noise, 15 years ago, the engine was noisy with the roller rockers, but not like this. I then starting looking online and started seeing things about push rod length using these heads. I got my current push rods from Hughes when I bought my rockers, they sent me an adjustable push rod and made me custom ones.  I figured these aluminum heads were the same as the stock iron ones I had so the geometry would be the same, but now I am thinking maybe I need to look into the pushrod length?

Any thoughts or suggestions?  here is a vid of the motor running before swapping out the lifters. the noise is still there now, just not quite as loud.

https://www.youtube.com/watch?v=rFh6mxFDMrE

after lifter swap

https://www.youtube.com/watch?v=j1JwHCEvy7k

[68CoronetRT]

I too get this noise you speak of. I just ignore it now, it's lifter clatter. Those aluminum heads are probably resonating sound a little more than the old iron heads did.

You need to measure the preload your giving the lifters as well. Mine are noisy but a loose rocker can make that lifter even more noisy(Which I've had). Have to find zero lash/pre load and then add .030-.060" to the pushrod for proper preload to the lifter. Even then they will probably still be noisy. With adjustable rockers you'd find zero lash/pre load and then crank it down 3/4 to 1 turn for your preload.

[bakerhillpins]

Are you sure you don't have an exhaust leak around the header? They can sound like a tick. Usually exhaust leaks get worse over time when a gasket fails but if it was that way from the rebuild maybe it just never sealed up properly?

[71 SE3834V]

Check the fuel pump push rod. I traced the source of my tick to the fuel pump lever clicking at the end of it's travel. Fuel pump push rod was worn down. My noise was quite evident when listening to it with a long screwdriver on the pump.

[timmycharger]

Thanks for the replies guys,  I did check for a leak around the exhaust when I first fired it up, I will take another look now that I have been driving it for some time now, maybe if there is a leak, I will see some evidence of it.

Regarding the fuel pump, I am running an electric pump so I can rule the push rod out this time.