301 knock

[mwrmedic]

I recently picked up my new project, a 79 GP with a 301, 90k on clock. The owner said it has an engine knock, well, I'm not crazy about the 301, I have a Pontiac 350 waiting to go in, but I need to keep the car mobile for now.
The knocking sounds like its coming from the front cover, but we also saw the flexplate cracked as well. We are going to check the timing chain. Any other findings of a knock from one of these besides a rod knock?

 

[pontiacgp]

I recently picked up my new project, a 79 GP with a 301, 90k on clock. The owner said it has an engine knock, well, I'm not crazy about the 301, I have a Pontiac 350 waiting to go in, but I need to keep the car mobile for now.
The knocking sounds like its coming from the front cover, but we also saw the flexplate cracked as well. We are going to check the timing chain. Any other findings of a knock from one of these besides a rod knock?

if you have a cracked flexplate then there is a good chance that is the source of the knock....I have also heard an engine with a knock that sure sounded like a rod but the knock was caused by carbon..you can cure that with steam cleaning it with water down the carb....if you want to check to see if a rod is knocking remove each spark plug wire one at a time, or ground the wire using a test light, while the engine is running...you'll hear the knock signifigantly decrease when you get to the cylinder with the bad rod..also if it is a rod you should see a flutuation in the oil pressure