393W noisy valvetrain

[8025dave]

I am having valve train noise with my 351w stroker. It is a pronounced clacking from both sides. Engine has about 1500 miles on it and runs very well, more power than the 1965 mustang its in can use. Details below.

393w Shortblock, eagle 3.85” crank, KB hypereuctic 11.1:1 CR pistons. Hydraulic flat tappet cam.
Heads: Edelbrock 60259, Performer RPM with 2.02 intake valves
Cam/ Lifters: XE294H (cam) / 832-16 (lifters)
Pushrods: Com Cam 7472-16, hardened.
Rocker Arms: Ford Racing M-6564-A351
Oils used: SAE30 and SAE10-40. Currently 10-40
15-20psi oil pressure at idle, about 850 rpm.

I have adjusted the roller rockers from the 0 lash point anywhere to +0 turns to +1 turn to get rid of the noisy valvetrain. Nothing has worked, although tighter seems a little less noisy. The noise is loud at idle throughout the entire rpm band. At about 3000 rpm with light throttle its very loud. At WOT you don’t hear anything other than exhaust noise so above 3000 I cant really say what the lifters sound like.
It has made this noise since I built it a year ago. I followed the break in procedure and the adjusting procedure thoroughly. I have adjusted the rockers at least 5 times and nothing really made much difference besides running them on the tight side, which still results in a steady clacking from both sides of the engine.
The lifters bleed down pretty fast, about half of them can be compressed by hand a little bit after its been sitting for a few hours. About half stay pumped up for days at a time.

Side note: I just put the same heads and rockers on a friends 351w and it made no rocker/lifter noise from the very beginning. It took about an hour to get it running and set up after it was assembled. 45 minutes of that was readjusting the rocker arms because he did it wrong. I have been messing with mine for a year. Pushrod length looks ok (stock). My thinking is that some lifter bores are bad, however I have never heard of this happening. Lifters could be damaged. The cam has an aggressive profile and maybe it’s a poor match for flat tappet lifters. Maybe they just have to be run tight (more than a turn on the rocker adjuster). At this point I am just guessing. I know aluminum roller rockers can be noisy, however this is not "noisy", its a definitive mechanical clashing noise that is not normally heard in pushrod V-8s.

Suggestions and ideas would be greatly appreciated. I purchased all the parts new in the last 1 ½ years.
Dave

[amick]

Valve train noise can be very difficult to trouble shoot at times but I will try to help you with this as best as I can over the internet. One thing that really sticks out to me is your low oil pressure. Hyd. lifters need a good amount of oil flow and oil pressure to conter act spring pressure. Could you tell me what spring you are running? Could you also tell me what your freinds oil pressure in his engine was?

[8025dave]

Hi- Thanks for the help.

I have been suspicious of the oil pressure since I put the engine together. It has a Melling hi volume pump so I expected more than 15psi at idle with 10-40wt oil. I would expect 50 psi at idle, not 15 psi. I googled some info on this and its not unheard of to have low pressure, and apparently there are plugs that can blow internally if a high volume pump is used.
My friends 351w has about 30 psi, although he is not 100% sure of this figure as the car is in storage now. It has an old truck 351w in it though. I saw one of the main bearing caps and it looked worn out. Bored .080 over too. Mine has tight bearing clearances (.0015-.0025) and its all new so I would actually expect higher than normal pressure, esp with the higher flow pump.

Perhaps my troubleshooting should first find the source of low oil pressure. I checked the oil pickup tube clearance and it was within the spec. It’s a Canton pickup and pan. I will be double checking this and pulling the pump next.

Dave

[8025dave]

The valve springs for the edelbrock performer rom heads are 120 lb seat pressure and 320 lbs @ .580" lift.

There is a chance the cam wants stiffer slrings. I remember checking all of this stuff when i built it but you never know, might have mised something.

[amick]

Those springs are not way off from what I would recommend to you. It is possible though that it could want a little more pressure in your motor. I would look hard at the oil pressure issue. I have seen motors run at low pressure like that before but I would certainly expect more from it, especially with the high volume pump. If you figure out your oil pressure issue please post it up, so it may help others as well. If we can do anything else for you or if you have any more questions just let me know.