"Oldy" spark engines use 3 parts gas and 1 part 70 weight oil...Just like all old 2 stroke outboard motors, 1/2 pint oll to 1 gallon gas....No roller bearings needed with that much oil...
big converted gassers like ST 3000s can get by with 10 % oil and no roller bearings...
One of the best old time glow fuels was sold by Duke Fox, 18% castor...21.6 OUNCES in a gallon...