Rebuilt in 2012, approx 500mi on rebuild. Mostly stock rebuild with 440source heads, 60303 Voodoo cam, stock rockers-intake-exhaust manifolds. Started up this morning and heard what sounds like a rod knock at idle that goes away with rpm. Link to youtube vid below, initially at idle, then rpm, then back to idle.

Haven't done any testing as yet, thought I'd wait for the experts to weigh in.

PS...good oil pressure, about 50psi at idle.

440 knock?

Video is private which means we can't see it. Are you sure it isn't converter bolts loose or hitting the shield?

Hopefully video is viewable now. Will check converter bolts, but doesn't sound like that to me.

what pistons?

It doesn't sound like a rod knock to me.

.030 over SRP 213455 (10.5:1CR) flat top with SCAT 4340 H beam rods

I would suggest you hit the parts store for a cheap mechanics stethoscope and see what you can hear. A rod knock should have gotten louder and more rapid with the RPM change.

I'd check the converter bolts. If it was knocking that bad internally it would have lost some oil pressure. Cut the filter open and have look before you run it again.
Doug

IIRC, a rod knock should "peak" with no load, just after bumping the rpm. Gonna put it up on the lift, check the converter bolts and underneath. Hoping its just a rattle.

probably a straight pin piston put in around .006". they'll talk to you when cold. if things quiet down when warmed up i wouldn't worry about it.

Too sporadic, Could be rockers hitting the valve covers, Flex plate / converter bolts or a multitude of other things. Silly question, is the timing to far advanced ???

sounds like a lobe or two leavin town.

It's not a rod knock...You're on the right track check the flexplate,convertor,etc...

Agree it doesn't sound like a rod knock. As said, check the external items like the flexplate and converter as well as the damper and pulleys. Once you eliminate the external items, you may have to go inside and look for something like a broken crank.

Too irregular to be a rod knock. Could be converter bolts I suppose. Actually sounds more like an engine external issue like exhaust pipe slapping against chassis.

Just saying from irregularity and that only is apparent at low rpm when engine bouncing about on its rubber mounts.

Go under car while engine is running. Place a stethoscope on pan and listen for something rattling about in it.

Oil pressure all ok? How does oil on dipstick appear,,,no shiny specks?

Did I miss if automatic or stick. If stick, push in clutch,,,,any change.

I like early statement on pulleys or belts or dampener.

Could pull lug wire off and on one by one while running. See if you can isolate it to one cylinder.

Here a classic rod knock with good oil pressure in my 340

Good news. Loose flexplate bolts, all 4. Thx to everyone who responded. Had to move the RR yesterday after taking the video in the orig post. The "clanking" was 10 times worse than on the video.

Drained the oil (due anyway) and it was clear. Cut the oil filter in half, nothing. Tightened the flexplate bolts, new oil/filter, started right up. Only thing I could hear was the lope of the Lunati 60303

Did you use loctite on the converter bolts? I would. Spend some time and snug all your other bolts and nuts up when its cold. You may have to snug some more than once between heat cycles for the first few thousand miles.

Check the convert bolts, Do you have a magnetic drain plug? If so plug it and look at it.. if it looks like "beaker" from the Muppets you have a problem. AMHIK. You can also pull the dip stick and hold it up to a bright light, if it looks like a glitter stick you may have an issue. I when I spun an bearing in the 1st 440 in this car it still had good oil pressure.