Ah! The infamous Vega! They cast the blocks in a foundry in Messina, NY, I believe right beside an Alcoa plant which piped the hot aluminum right over. The problem was the coating they put on the cylinders to harden them; it just did not last, causing early oil consumption.
In addition, the engine block itself was used to radiate some of the heat since aluminum is a good conductor of heat. This allowed them to equip the Vega with a miniscule radiator.
Unfortunately, these engines both leaked and used oil, and dirt on the engine block soon destroyed its heat radiating capacity, causing more overheating, etc.
The rest of the car was subpar as well; GM’s halfhearted effort to meet the foreign competition. This car was a dog, and even the most dedicated maintenance could not keep it on the road.
One of our regulars owned a Vega, I believe. He will no doubt have additional war stories to tell.