Technical Flathead knock/tap help!

Ok, as title states, we are having some engine noise in a 1950 ford flathead v8, hopefully the video posted is good. No change with fan belts off. We have removed the intake, checked valve clearance(adjustable), all ok. No fuel pump rod, runs on electric. Went ahead and pulled both heads, have not checked valve lift yet, don't have my gauge with me. nothing looks like it has been hitting. Engine starts and runs/drives good with good oil pressure. I am thinking possibly a loose wrist pin, it sounds too high in the engine to be a rod bearing? From the looks of it, this engine has been gone through, no sludge and combustion chambers/water jackets etc. looks clean. Just wanting to know if anyone has any ideas before we dig any deeper.

VIDEO LINK:

Thank you,
Dan

 

what happens when you rev it up? Does the noise change on acceleration/deceleration?

 

Pull the spark plug wires one at a time with the engine running to find the cylinder that is knocking. When the noise changes you found it.

 

Noise changes with RPM's, but doesn't go away

 

we tried the spark plug deal, nothing definitive there. Was really leaning on a loose valve.

 

sticky valve? valve springs ok?

 

I'm going to bring a dial indicator over and measure the lift and check the springs/keepers, we just rotated engine over and checked clearance and made sure none were obviously broken or loose.

 

I had the same noise in my 47, slight noise at first, after about 6 years just like yours, turned out to be a wrist pin keeper had come out of the piston and the pin was moving side to side and grooved the cylinder wall, had to re sleeve and rebuild the bottom end.

 

Piston Slap?

 

At this point you might as well "pull it" & tear it down for inspection, because if you don't , you will always have the "nagging doubt" that you missed something, & obviously something IS wrong, so why delay the inevitable??

 

After looking over everything again. We did find this on one of the lifters. Not sure if this could be the culprit or not. Any input on this would be appreciated.

 

Time to pull the engine and find those pieces before the real bad $iht happens.

 

So what happened? what fixed the noise?

 

If the last pic is a lifter bore you should have it machined and sleeved. Also check the timing gears. It probably has an aluminum cam gear. When these get badly worn they can knock just as you describe . It would sound just like a knocking rod.