cpenrose

I cannot figure out the source of a tapping sound in my freshly built motor and it’s been driving me nuts. I’ve adjusted the valves 20 times 1/4 turn 3/4 turn everything. Had a collapsed lifter that I replaced still not fixed. Had an exhaust leak from loose bolts, tightened them and sounded like it mostly went away. But now it’s fairly loud and definitely sounds like a metal on metal tap. Lifters all have their retaining clips and rollers all spin nice and smooth with no damage. Roller rockers are all in good shape from what I can tell. I don’t know what else it could be. Timing chain is my next best guess but definitely sounds like it’s coming from the top of the motor towards the center of the intake. This isn’t the typical sewing machine noise I’ve had this motor for years definitely not normal.

SS RRR

iTrader: (2)

Loose spark plug can sound just like valvetrain noise. Possible it could be a collapsed lifter. See if you can post a video if possible.

wannafbody

iTrader: (2)

Make sure you don't have a broken exhaust manifold bolt.

cpenrose

Here’s a video

cpenrose

All the header bolts are definitely tight. Could be a gasket I guess but doesn’t sound like an exhaust leak at all to me

SS RRR

iTrader: (2)

I hope I'm wrong, but it sounds too deep and fast to be valvetrain.

cpenrose

I don’t know sounds a bit light to be a rod knock. I had a rod knock before rebuild and I think I remember more of a clunking sound. Also still have great oil pressure

BALLSS

OP, did you clearance the valve covers for the RR?

cpenrose

Same rockers and covers I’ve had since I got the motor

BALLSS

The only RR that clear stock VC were the Crane, also GMPP, Gold Narrow Body ones. Anything else the VC drip baffles need trimming on intake side so if yours are not, look for any witness mark on them. Some did bend them away but most just cut them (pic), courtesy of Golen Engines

cpenrose

I believe they are cut like that I have to check

cpenrose

The covers are in fact cut already. I just pulled the intake yet again after I watched it run with the covers off. And saw the rocker that seemed to be following the tapping sound. It’s the single lifter I changed out recently. Pulled the lifter and looks pretty good to me. Only thing I noticed is the roller is clearly rubbing on side of the lifter body. So I’m think maybe the cam lobe has a slant and may be pushing the roller to the side every rotation? I find it hard to believe that could make that loud of a tap especially on a new lifter. But I can see the marks from it rubbing on the side of the roller and lifter body next to the roller. This lifter was swapped because the last one collapsed. Not sure if this would have anything to do with that