recommended oil 1956 KLC

what oil should I run to be sure that i am using a high zinc based oil for the older engine? I read somewhere about "green oil"? Also what is oil capacity?

I don't have a K model engine, I have WB200 engines and I have always run 40w non detergent oil in the summer and 30w in the winter.I have always bought industrial grade engine oil for stationary engines, Equip was the last brand I purchased and I bought 100 gallons a few years ago. The engines have never been torn down and have 40 years on them 3000 hours roughly. They are tired but still have 30 psi at idle and 42psi at higher engine speeds 1,950 rpm.

They take roughly 11.5 quarts to the top notch on the dipstick but they lay very flat in the boat. They would obivously take different amounts with different install angles.

Sorry I cant be more helpfull.
Bluecometk

Go with the straight weight non detergent oil. I have found it at farm supply stores and sometimes at Wal-Mart. Put six quarts in. That is enough to run it. put the boat in the water and check the oil. K series Usually takes 6-9qts. Depends on how good a job you did at getting the old oil out.