[Ron85]

I am wanting to pick some of your guys brains
I am thanking about buying a 400 from my buddie
He is having problems with it he bought it from a guy who had it all redone 30 over double hump heads roller rockers the guy could not get the rockers to stop making noise so my buddie bought it
He put a new comp mother thumper flat tappet cam kit in it and still doing it
It is getting oil to the top end and the gauge says 40 psi but we can not get them to stop tapping
we put 2 sets of lifters in it no change when you take the pan off and intake you can tell it is new bores still have cross hatchings in them the lifters fit good also
has any one had this problem I am thanking they stuck a plug in the wrong spot any help would l be great thanks

 

[techinspector1]

Next thing I would do is yank the roller rockers and bolt on some stock stamped rockers to see what happens. You've pretty much eliminated all the variables except the rockers.

Bring the #1 piston to TDC on the compression/firing stroke. Back off the nuts on the intake and exhaust valves on #1. While holding the rocker arm tip down against the valve stem tip, jiggle each pushrod up and down while you tighten the nut down to zero lash. Move the pushrod around a little to make sure it is seated in the pushrod cup of the lifter and not up on the face of the lifter. Give the nut another 1/2 to 3/4 of a turn. Adjust both intake and exhaust.

Turn the crank 90 degrees clockwise (1/4 turn). Adjust both valves on the next cylinder in the firing order (#8). Continue doing the rest of the valves in the firing order (1-8-4-3-6-5-7-2). To adjust all the valves, you will make 1 3/4 revolutions of the crankshaft.

 

[lg1969]

I would check the spark plugs to see if not hitting the piston.
Also check if the inner valve spring are not broken. :smash:
Do you have 40psi cold or hot?

 

[SDLuck]

noise

What spring are in it had a small block chevy make noise had solid roller springs on a hyd roller,do the rockers clear the spring retainer,does the retainer hit the valve guide,do the rockers clear the studs?

 

[lg1969]

Broken valve spring on the heads can make a lot of noise. Food for thought

 

[454C10]

check the wipe pattern on the valve tip. roller rockers need the push rods exactly the right length to run quiet.