Weird Engine Noise

[67 GTX]

I recently started up my 440, and after the oil pressure finally built up, it was noticed that there was a strange hollow knocking sound coming from the block, more specifically from the front of the block.

It was initially thought that the noise was coming from the fuel pump, but now I am not so sure. The noise appears to be coming from the middle of the block, around the water pump area.

I had the motor apart, but only to cosmetically freshen it up. The intake and exhaust manifolds were removed. The fuel pump was removed, and it was found that the fuel pump rod was slightly bent. So that part was replaced, and the fuel pump was put back on. The oil pan and windage tray were also removed, but just to clean them.

It was a running motor before pulling it, and there were no such sounds beforehand. When I say running motor, I mean up to the beginning of this past June. This has been an on-going project, so the motor was not sitting around for years.

It is a completely stock 440 motor. At first I thought it was the crank hitting the windage tray, but I can't imagine that's the problem. The windage tray was fine before removal, and it can only be reinstalled one way.

I am completely stumped at this point, and welcome any ideas!

Thank you in advance

 

[Pops1967GTX]

Get a stethoscope at the auto parts store ...
First off, eliminate all of the accessories like the alternator, power steering pump, water pump.... Remove belt. start engine for about 15 sec... & see if noise is present......

With mechanical fuel pump mounted to the engine. Before the engine gets too hot, put your hand on it. If it is making a noise you should be able to feel it.

I’m thinking Possible oil slinger or harmonic balancer against the front cover.

 

[super-bee_ski]

Does the noise (frequency) increase as you build RPM?
Does the noise dissapate as oil pressure builds up and engine warms to operating temp? (Connecting Rod bearing)

 

[67 GTX]

Crisis averted everyone!

It turns out that there was slightly too much free play on the clutch, so most likely, the throwout bering was rattling. This sound was propagating through the crank, hence why I heard it towards the front of the engine. I found this out after stepping on the clutch. And then once the clutch was adjusted again, the noise went away.

It still comes back slightly at times, but at this point, I am going to attribute that to the brand new clutch assembly.

The weird thing was that the clutch was adjusted before the motor was even started, so just maybe this new assembly is finicky at first.

 

[miller]

Guess we'll hope your crank 'bushing' is in good shape. (That's the one in the crank's rear, where the clutch pilot shaft goes.)

Not trying to be a wise guy. Never know who knows what.

 

[67 GTX]

Guess we'll hope your crank 'bushing' is in good shape. (That's the one in the crank's rear, where the clutch pilot shaft goes.)

Not trying to be a wise guy. Never know who knows what.

No offense taken.

The bushing is brand new. It was replaced when I had the motor out.

 

[67 GTX]

Just curious, has anyone else experienced this?