Thank you for the Question XXXXXXXXXXXXXX,
If you only put "One Quart" of oil into the engine, you were not down enough to cause any damage by lack of oil....
Obviously, I cannot hear the "Clanking" noise over the Internet, but these types of noises are always better served by an "Experienced" mechanic. I can hear, and have heard lots of noises in engines through my years. And I can tell you that in many cases the noise is not as severe as the customer thinks...
Some Questions that may help:
How long did you run the engine and at what speed after the noise started?
Did the noise get any louder when running?
Is it more of a tap, say with a screwdriver on the valve cover or a rap, like a hammer on the block?
How fast is it clanking, does the frequency change with the rpm of the engine?
Take the alternator belt off and see if the noise goes away?
Check the drive oil for metal in the oil, and the same for the engine oil, ?
Many timed the noise if coming from the outdrive, u-joints, gimble bearing, etc....and the removal of the sterndrive reveals the noise to be in this area....
Marine Mechanic
21 Years Experience as Mechanic, 18 Yrs Boat Yard Owner/Mechanic, Factory Certified