VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 non-detergent motor oil

What are the benefits, if any of using a non- detergent motor oil in an older vehicle with unknown mileage which has spent many years in storage

While there are no benefits - these are my thoughts.
Some believe that using detergent oils will loosen gobs of sludge that will then plug-up oil passages. This, for the most part is not true as the detergent basically keeps new sludge from forming and will disolve a only small amount of old sludge.
If your engine is from a year that had the dippers and oil lines in the oil pan troughs (1935-1953) I would strongly recommend removing the pan and testing the oil lines (with water pressure) to make certain the rod bearing are reveiving oil. For any engine there is a good possibility the the oil screen is plugged with sludge so it should be inspected.
The disadvantage of non-detergent oil is it has no additives to prevent rust and corrosion, prevent wear, prevent foaming of the oil, or prevent sludge from forming.
Removing the rocker arm cover and and observing the sludge build-up would give some indication of sludge build-up.
At any rate I would change the oil now and change it again in about 2 hours of running so as to flush out any undesireable material.
What year is this engine?

Thanks for your thoughts, Its a 1917 Chevy with no valve covers

Detergent oil is fine in any engine with a functioning oil filter. In an engine with no oil filter non detergent should be used and as part of regular maintenance the oil pan should be removed every other year and the pan and troughs cleaned out. With non detergent oil the carbon and tiny metalics drop out of suspension over night and form sludge the pan which sounds terrible, but it is a good thing since the sludge stays put and doesn't circulate with the oil. With detergent oil the particals stay suspeneded so the filter cam filer them out saving the bearings from extra wear and the pan from collecting sludge. I do agree if you don't know the condition of the oil pan inside and it has sat for a long time. it might be a good idea to at least take a length of bailing wire and put a tiny loop in one end and fish it down through the oil fill pipe to the bottom of the pan to check for sludge and how deep it is.

My Experience: When I started driving our 31 in 1965 I used non-degergent oil. I changed the oil every fall when I put the car away for the winter. About 1973 after reading articles I used two quarts on detergent and three quarts on non-detergent for one season. After that I used straight detergent 10W30 detergent oil. After 40,000 plus miles everything is still just fine. I still change the oil every fall as part of winterizing. I start the engine and let it run about 20 minutes, shut it down and it is ready for winter and the next touring season.

I would still drop the pan and clean out was has setteled in it over the years. After that 10W-30 detergent or #30 detergent would be fine.
I have ran 10-30 in my 1934 and 1939 with no oil filter for the last 40 years with no problems. If I removed the pan for some reason there was very little "junk" on the bottom.

I will not go into the chemistry of motor oils as it takes much more space than justified. Let it suffice that I use detergent oils in all my old Chevrolets including one from the teens. The basic reason is that many conditions have changed since these vehicles have been manufactured, road conditions may be the greatest.

To keep it in perspective, i guess it would be okay to use non detergent but i've always seen it as that OILS TODAY are so much better than what was available then, so why not improve on the oil by cleaning the engine out, then run a detergent oil to KEEP it clean. After all, oil is the life of the engine. The myth be that it be bad to run detergent in a non-filtered system, but if this were the case, even small engines of today run detergent, most have no filter system, and they are built of aluminum which is softer than cast iron. If it's any place that is full of myths and BS as iceing, it's the small engine world of which i were apart of for 16 years and i was good at what i done. My point is, is that if your smaller engine can run detergent and it contains no filter, then it surley wouldnt hurt the much sturdier built cast iron automobile engines of which im also fimiliar with. After all one of the reasons detergent oil was invented was to keep from having to pull oil pans all the time to go on sludge patrol. Once the engine is clean, KEEP it clean. detergent will do just that.

However i would not reccomend it on an older engine thats always run non detergent and has never been rebuilt. Reason being is that detergent oil WILL clean your engine through and through and pretty soon if your rings are a little weak, you'll start to smoke. That unfortunatly is fact. SO...there is a bright side to using non-detergent. If you dont want to rebuild that old engine, use non-detergent.

When I acquired my '24 Superior it was a non-running car and had not run for an unknown amount of time. The first thing I did was drain the oil and re-fill with new (non-detergent). It only took 3 quarts which sent up a red flag. I drained the new oil, removed the pan and proceeded to remove over a quart of "solidified gunk". I then throughly cleaned the semi plugged lines and channels then replaced the pan. All this to say that, particularly on the older open overhead valve engines, I would in the future remove the pan first. I can't imagine all that gunk being stirred up into a running engine. With the pan and lines clean I then switched to detergent oil and have had no problems.
Bill R. '24 Touring

Thats good! But not every time is a success story and thats what im pointing out.

The best thing to do on any old engine is to pull the pan, valve cover, side cover, oil pump and the rockers off. Then clean out all of the oil passages. This way you know if there are any restrictions that may lead to engine failure if not cleaned. I have also seen rocker arm shafts plugged with gunk. Re-assemble and put in a good quality engine oil.
The oil made for desil engines have the highest level of additives for wear protection and particle suspension. Non Detergent oils are not good for an engine. I use it in all of my cars. My new rebuilt engines also have the zinc additive added as well. P.S. oil is a cheap investment that helps prevent very costly repairs.

Thats exactly right. Non detergent was all that was available THEN. But it's like i said, if the engine's in good shape, clean it out and run detergent. It will then KEEP the engine clean. Not advisable if you have rather low compression though and this is something i just pointed out. That "dirt" in your rings will often be the only thing keeping the engine from smoking if it's an older engine. When you use a detergent it will CLEAN that junk out but then your engine will start to smoke. Thats were i said, if your engine is old, maybee not in the best shape at the moment and you dont have the time nore money to do a rebuild, run non detergent. It wont hurt it. it just means give a little attention to the engine...perferably SOON.