I remember reading about oil capacity on this forum and can't seem to find it. I have a '25 Touring. Manual says 4 qts but I seem to remember 5 was recommended. Can too much cause a problem? Is 40w non-detergent correct?
Thanks,
Jerry

Sadie, I put 5 quarts in my 1928 which has the original type of filter, The dipstick shows a full line at less than five quarts but I fill to just above the FULL letters.

I kinda have a different outlook on oil for these old dip, sling and splash oil systems in very good to good mechanical condition, I believe that a good multi-grade (10W-30)top of the line motor oil is better, first, it keeps the engine cleaner from change to change by keeping the carbon and contaminates in suspension and second, the better flowing grade of oil gets into the reservoirs and into the rods, mains etc. faster and better. That is just my humble opinion. As for changes, I like to change oil often every 1000 miles or at least two times per year. Once when we hit the end of the touring season (we drive locally all year) and then in the Spring before touring season gets going at full speed.
I have two other cars that we tour with so the old four banger isn't being driven as much as a year or so ago. We pick the more diffucult touring roads for it, more hills and natural dirt roads, just not so many miles.

I've never owned a 30's car, let alone a 20's car. So maybe things are different for the older sixes and four cylinder engines. However, I wouldn't think so.

I was 'taught' to NEVER use a non-detergent oil. With few exceptions it's been 10-30 in my 216's 235's, 265's, 283's, 327's etc. etc. up to BB's.

As I understand it, detergent oil helps keep the engine cleaner. Detergent.... DUH!!

Bill.

Detergent oil is the way to go.

Sadie I have a late '25 sedan that has the same motor as your car. It takes four quarts of oil. Over filling the crankcase causes oil to foam. This isn't good for the oil that is going through the pump to the main journal. Use detergent oil(10W-30). Change it regularly,(about 500 miles) because you don't have an oil filter.

detergent vs NON,
I was told by a man who operates a garage in my area that specializes in "old" cars - if you are uncertain about the engine being rebuilt, use 40w non-detergent and about 20% Lucas oil additive. If the engine was rebuilt then use detergent.
I'll go with whatever you guys say - since you're the owners of similar cars.
Thanks,
Jerry

I had an uncle born in 1913. He pretty much grew up with these old cars and was probably the best mechanic I ever knew. I'm not saying that because he was my uncle either.

For many years he specialised in working on old cars. He retired sometime in the early 80's.

He always said if you were unsure of what kind of oil had been used in the vehicle to go with non-detergent oil. Otherwise to use a good grade detergent.

He also said, as above, that over filling the crankcase was not good as the oil would foam causing small air pockets. This gave the same effect as being low on oil.

It seems like Mr Mack uses five qts because he has an oil filter on his. 4 qts for the crankcase + (about) 1 qt for the filter would make sense to me.

I suppose if an engine is 'old' or 'tired' or whatever, it would be best to use NON. Otherwise, it seems that detergent is the only way to go.

Bill.

That is right Bill, even though I am not really sure that the filter drains completely.
I also remember what the engines looked like on teardown in the days back before detergent oil was common, I really don't think engine sludge helped to keep the engine together.

I could almost tell you the make of the oil by the amount of sludge left in the crankcase. I always hated the way Texaco Havoline looked and smelled in an oil burner engine but the engines were much cleaner than other major oil company brands.