Should I use a break-in oil?
I am in the process of overhauling the engine in my 1954 Studebaker Champion and I was wondering if the old rules still apply. Years ago we used to break in engines with a good 10-weight non-detergent oil. We’d run it for about 500 miles that way and then drain it and refill with the correct oil. Is that still the best way?
You no longer need to use a 10-weight break-in oil, though I am rather old school about changing oil at 500 miles and examining it for metal flakes or other debris.
But before the engine is even assembled, the oil galleries should be carefully cleaned out using light motor oil and a rifle bore cleaning kit to make sure that none of the machining swarf and dirt is left in them. Those sharp metal chips can go right to bearings and ruin them in minutes on start-up.
I would then go with a quality 10w30 detergent oil that contains an adequate amount of ZDDP (zinc dithiophosphate) for antique cars (12,000-14,000 ppm is what you want).
And while you are putting the engine together, use a little cam lube on the lobes of the cam, and make sure all the bearing surfaces have a coating of motor oil. Also make sure to fill the oil pump before installing it, because if it has air in it, the pump will just cavitate and your engine will be starved for oil at start-up.