29Cabriolet
Senior Member
I thought there was a thread on this but did not show up on a search. What Oil weight do you use? Also there is a debate on detergent v. non detergent. What is best for a not recently rebuilt engine?
There are a bazillion discussions about oils.
Some fellas insist on using non-dispersant, can't imagine why.
Some fellas use synthetic.
Most guys use something in between. I've been using Rotella 15-40 for decades.
IMO, and from what I have read. Some of this is debatable.
Non-detergent multi grade oil was not available in the 30s. Sludge filth settled out and also adhered to the surfaces of the oil system, so the circulating oil somewhat stayed cleaner. Periodic maintenance/service including dropping the oil pan and removing the valve access cover to clean out sludge and the oil pump filter. Issues arose if the shade tree or typical owner for the A skipped or did not know this, and this service was not performed. So non detergent oil is ok, as long as you periodically service the oil pump screen, valve access area, and the oil pan/bottom end. It may even be preferable since the filth settles out and not as much filth is constantly circulating in the oil.
For multi grade detergent oil, all the filth stays suspended in the oil. So unless running an oil filter, all of what is in the oil is constantly being circulated through the moving parts including the Babbit or Inserted main bearings. This is why since my motor is does not have an oil filter I prefer to change every 500 miles. Oil is cheap compared to the cost/hassle of rebuilding a motor.
So accordingly I'll assume from the sound of your response you use non-dispersant. Thats your choice.
I'll agree oil is cheap insurance, doesn't take long to change it.
16 ounces to the pound.
I use Shell Rotella T4 15w40, change every 500 miles, buy the 5 quart or 10 quart containers on sale. The Farm & Fleet store here frequently has mail in rebates that brings the cost down further. Use it due do to price point, it is available just about from everywhere in case I need some quick or on the road (have yet to need any on the road), has a little Zinc in it, and is a decent oil. Is it the best oil? Who knows, probably better oil out there, but if changed frequently is so much better than what was available in the day. And those motors from what I have read lasted 40,000 to 70,000 miles.
As a side note, saw my father once pour something (kerosene?) in the oil in of one of his old tractors and running the tractor for a couple of minutes before draining the oil (he collected old Masseys). I asked him about it. Told me his father did this occasionally on his tractor and on his Model A to flush the motor instead of dropping the pan to clean out sludge. On the tractor added it , ran the tractor a minute or 2 at idle, drained it, then filled with new oil. On the A, added the flush, ran the motor for 1-2 minutes at idle, drained the motor, would pour 2-3 quarts of old non contaminated oil through the distributor hole and breather/fill tube to clean out the oil galley and dipper tray and let it drain. Then filled with new oil. Just saying this is what my Grandfather with 5 kids with a live in house keeper since wife died due to complications of child birth, and was a dirt poor subsistence farmer who sharecropped in Minnesota/South Dakota did - not sure if this is ok to do.