Guys, I appreciate your inputs "always", but hear me out.

I will continue to use the non detergent oil in my 1929.

Why you say? (long discussion – sit back, relax).

First, all oil used in our autos starts to break down as soon as you add the oil to your engine environment. The heat, condensation, acids, etc starts to change the oil purities. With an engine routinely running, it is best to change the oil at 90 day intervals to insure the machines quality of design and performance for the long life of the engine.

Most auto owners, never change the oil until their vehicle is required for some other service and then the auto technician notices the old oil and informs the owner they need and oil change. Then there's the other owners who might change their oil every year at best. Then there's the somewhat concerned auto owner that may change the oil earlier than one year. This last owner is the better of the three mentioned above in order to help the machine or in this case an engine, to meet an expected life duration of the engine. Or even extend its life.

What has not been mentioned in that info above, is the fact of an oil filter change with the oil change. The oil filter removes the contaminates (particles) suspended in the oil in order for the oil not to collect on the surfaces inside the engine. Therefore, while most particulates are suspended in the oil (particulates afloat) , the filter may remove those particulates. The better the filter, the better the removal of all particulates. This process thereby helps eliminate the build up on those surfaces in the engine. But note, the oil properties (its quality) in all three processes of oil change mentioned above are different. And due to those oil properties changing, accumulation on surfaces will still occur regardless of the removal of most particulates. The filter process will not eliminate particulate build up. And note, particulates are only one part of the oil breakdown process.

This info above relates to the majority of us owning and maintaining our automobiles of today. If I were to mention those who race their modified autos, they change their oil and filter per each race. I, my career, is from the engineering aspect of manufacturing. Manufacturing process equipment, requiring oil, requires not only frequent oil changes but high quality oil filters per each change out. Some equipment requires more frequent filter changes than the oil. Machine manufacturers oil and filter change requirements are always met and mostly we modified over and above the Mfg requirements to extend the machine life expectancy.

I could go on and on with this, but my 1929 engine does not have a “filtering process” that we are commonly accustomed with since the 50's to date. But, my engine design, utilizing non detergent oil, is expected to allow the particles to settle/accumulate in the bottom of the oil pan known as sludge. And I am expected to remove such sludge as needed to properly maintain my engine. As to the upper areas of the engine that has horizontal surfaces, areas that do not flush consistently with quality newer oil, those surfaces will allow particle (sludge) accumulation over time, known as build-up. Note this even happens in our engines today if poor maintenance is present, even utilizing detergent oil.  Detergent oil prevents oil particle accumulation on engine interior surfaces.  That's its design.

If I were to use detergent oil, in this 29 engine, “all” of my engine oil particulates, its particulate matter will increase in time in the detergent oil and I cannot collect or remove it and it will consistently flow throughout my internal engine parts. This is not good for proper internal engine wear that I can help control by using the non detergent oil designed method of this engine and allow most of the particulates to collect in the bottom of the oil pan.  Yes, accumulation can prevail on interior surfaces where those surfaces will not receive continuous oil contact.  But more frequent oil changes reduce this occurrence dramatically by limiting particle accumulation in the oil itself.

Here's the Crazy Info ....

With my 29, I will change my oil in the spring (say April when my truck comes out of hibernation) and then in August. That's four months of usage of fresh oil in my engine for run time usage. When my truck goes into hibernation (late November) for the winter, the oil will be drained from the pan and a note of “NO OIL PRESENT IN THE ENGINE – ADD 5 QTs” will be placed on the steering wheel. The battery will be removed and placed in my home work shop, possibly on a charger if needed. And I will put a little MMO in the cylinders. (this is being performed next week too – just took the front end apart for king pin repair).

That's only 4 months of usage of my new "non detergent oil" in my engine. This first summer period I put less than 60 miles on my truck due to repairs required. Typically I will expect to put maybe 200-300 miles on my truck, at the most, per year and hold to “my” oil change requirement. Sludge and build-up will be extremely limited at best. Each winter I am planning to drop the oil pan and review sludge accumulation. Results will determine if each or every other year removal.

Just a note, even if one were to drain their old oil and then add new oil to the engine, and not run the engine, the new oil, just sitting in the oil pan, starts to break down. Over much time, that oil is no good for the engine design requirement.

My experience with engine rebuilding in the late 60s and 70's, 99 percent of those engine tear downs revealed serious sludge deposits not only in the oil pan, but in the valve covers and the top of the heads.  And that was those owners using detergent oil.  They were the ones that never changed their oil as I stated above.  Only a few rebuilds, which were a 67 440 coronet and my 70 GTO Judge, tear downs revealed those areas I mentioned were like a brand new engine, but there had been years on those vehicles.  The guy who owned the 440, changed his oil and filter, religiously, every 2000 miles.  I changed mine every 4 months ( I still do with all my vehicles past and present and I'm now 71).

I apologize for the long explanation.

Gary

Most owners don't fall under your assumption. Most owners (at least those I know) change their oil often and use detergent oil.

All moving oil has particulates suspended. Detergent oil allows them to be eliminated during the 1000 mile or less oil change.

Non detergent oil allows the build up of sludge.

Sludge is bad.

Sludge plugs up oil passageways.

Plugged up passageways causes moving parts to fail.

Failed parts are expensive.

Don't allow sludge to build up.

Use detergent oil and change it often.

Yes, in 1929, it was the preferred method to allow sludge to build and manually clean it out on occasion. Detergent oil wasn't invented until 1931. Speaking metaphorically; I don't still wash clothes in a galvanized tub with a wash board just because that's the way it was done in 1929.

It's your car, do with it as you wish. I don't agree with your reasoning.

Tiny,  I do understand your logic.  And the majority also agree with you.

But you do understand the oil within an engine, do to heat, age and the other characteristics present the engine environment, its properties change.  And so do the additives, even the detergent.

Sludge is a big problem, as you state, with clogging.  And the oil properties change, so does its lubrication qualities to prevent part wear.

And the sludge issue will prevail with "all" oil used in engines due to poor maintenance and the age of the oil being spent within the engine.

My input to all, is to change your oil, and the filter, as frequently as necessary, to prevent excessive wear.

Thanks, G

@junky 

You do realize that you are forgoing other qualities that go along with the additive package containing the detergents, right?

Like anti-wear, anti-foam, anti-oxidation, etc ?

The anti-oxidation aspect alone means the oil will last far longer without "breaking down".

As Tiny says, it's your car...

Keep in mind though that it's not just Tiny or I who disagree with your reasoning, it's entire industries... lubrication, engine manufacturing, etc.

PS

I've seen engines that took a couple of years to rack up 100 hours and went that long between oil changes.

But, they had top quality diesel oils in them, and there was no sludge accumulation whatsoever when opened up.

Guys.  I understand your position as do most people.

I did not rule out any other additives.  That's why I listed it as additives (plural).  I did focus on the subject of the "sludge" particle issue, filtering and its common issue of collecting and therefore clogging of ports/passage ways issue.  And that's all due to the break down of the oil in question.

My overall point is that, oil breaks down in its usage in the engine.  And of course, so do "all" of the additives included.  And the serious issue to this happening is that we all should change our oil more frequently than what most people think. In order to have the most over qualified oil in the engine at most times.

[If the designed oil for auto engines could never break down or at least lessen its superior quality to the point of the engine design need, we would never be required to change the oil or even apply a filter process.  We would only be required to "top off" the oil level due to its wear out.  but the wear out of the oil would present accumulating residual spent oil.  Ehhhh]  Yes, this last statement of mine is stupid because that condition will never happen.

The oil designed for our automotive application is superior than what the engine requires for its designed usage.  Once that oil is introduced in the engine, the run time of the engine, eventually,  changes the quality we then call oil break down..  And it's not for the better.  It's getting lower than what the engine need for its Mfg life expectancy.  I can't get into the full explanation of the oil, its lubrication and its usage in machinery, due to confidentiality agreements when I retired. 

My knowledge and experience, with oil and lubrication has been to extend the life of a machine far greater than the mfg expectancy, and for machines much greater in design than of an auto combustion engine.  And that is only one facet we designed into those machines, but a very much required piece of the puzzle to extend its life which also cut down "production downtime" due to standard machine repair.

This puts me in the position that "my statements are not of assumptions".  Its of knowledge and experience working with far superior machines ranging from say 400k to 2 mil plus off the shelf machines.  Heck, we even pulled an 1800's machine out of the ground that had been burried for decades, because of a fire, and rebuilt it to our knowledge and experience and its still operational today, far better than what the mfg originally designed, and it will be for another 100 years as long as "proper maintenance" is applied to that machine.  And we did that to all of our machines in the production process.  The cheaper designed machinery is better to leave alone and buy another when needed.

Without my getting into further details, and thereby putting my life savings, property and 401k into jeopardy (confidentiality agreement), I, worked 30 years with Professional Engineers, Mech, Elec, Chem, Civil,  and have extended mfg machines beyond 50 percent of its mfg machine life expectations.  And we recycle, rebuild those machines at our expected point of life recovery.  They all are still running today throughout this country.  And it revolves around this subject matter.

A combustion engine, past or present is a simple machine in respective.

If sludge plugs a passage way, or hampers an engine part of its duties, its not due to the break down of the oil...it's due to poor maintenance, regardless of detergent or non detergent oil.

G