Other: Non detergent oil

[Edsel Face]

Historically my '51 Champion has been on a diet of 30 W non detergent oil and ZDDP, according to the prior owner. Should I maintain this diet? There is no oil filter.

[Skip Lackie]

There certainly is a danger that detergent oil will loosen up some sludge and it will migrate to some of the smaller oil passages and clog them up. If you only drive it for hobby use, I would stick with non-detergent, unless you take some actions to clean out that sludge. Others may not agree with me.

[Edsel Face]

The sludge issue was my concern.

[EnduroDriver]

I run synthetics in everything I own, modern oils are amazing but your situation would certainly make me consider sticking to the old recipe. The sludge potential would be a pretty big risk without a filter. You could inspect a lot of the engine internals by pulling the valve adjust covers, use a bore scope through the oil pan drain plug and oil breather(s). If that visual inspection yields a clean engine you might have some options.

[Edsel Face]

I think I'll just stick with the current menu. If the motor ever needs an overhaul, then I'll go with conventional oil. Thanks for your input.

[Dwight FitzSimons]

Rather than suddenly switching over from non-detergent oil to high-detergent oil, why not gradually switch? AFAIK one can mix ND oil with HD oil, at least if one sticks with the same brand. That might gradually clean any sludge out of the engine. Of course, if there is a lot of sludge then that changes the equation completely.
--Dwight

[RadioRoy]

This is a good reason to put an oil filter on the engine. There is actually no good reason not to put one on the engine.

[Skip Lackie]

If you decide to convert gradually and/or drop the pan and clean out the sludge, you absolutely must add an oil filter to catch the stuff that you missed or stirred up.

[Corbinstein0]

I'd drop the pan and clean it up. Then pull the valve covers for inspection. However, at this point I would not switch to modern oil.
and definately not synthetics, as they tend to clean well enough that the old dried up seals go to leaking. BTDT.

[Bud]

From what I've read and heard from the tech reps at both Shell and Chevron, modern compounded oils will not loosen and cause big chunks of sludge sticking to the inside of the engine to start floating around in the oil possibly clogging something. Modern oils while they do have cleaning power due to their additive packages will not remove massive amounts of sludge at one time. The newer oils are meant to keep engines clean and not to clean up a nasty one. The use of an engine flush such as a load of Seafoam in the oil can loosen up sludge and possibly cause a problem. I've switched to modern compounded oils in engines that have been poorly maintained and or have a mild sludge issue with no problems. Some of the myths such as switching from a non detergent oil to a modern compounded oil got started who knows when along with not storing a battery on a concrete floor are old wives tales and do not relate to anything produced in the past three decades. Also switching from a conventional oil to a synthetic oil in an engine that is in good condition is another old wives tale as the synthetic oils being produced today have additives to protect the seals and in some oils such as Valvoline Max Life, have additives to improve the condition of the seals. If the engine is so full of sludge as to be a problem, then the pan and valve covers need to be removed and everything cleaned out. Bud

[345 DeSoto]

One quart of Rislone added to each oil change (in place of one quart of oil) will gradually clean up a dirty engine...

[Ron Dame]

My grandfather bought a '52 Land Cruiser new, and AFAIK, non-detergent oil was all there was. He used it, and used it hard, but again AFAIK, was fastidious in maintenance. Somewhere in the late '50's or early '60's, (as the story was told to me) he switched to detergent oil and soon spun a bearing. It was parked under a willow tree. I recall as a little kid in the early '60's starting to throw rocks at it trying to break some glass, when his strong arm grabbed mine in mid-throw, and with a face that told me I would never consider doing that again. Sadly, he died a few years later, and my grandmother had it, the Whippet, and a few other cars scrapped.

[Dan Timberlake]

The 1950 Chevrolet Owner's manual recommmended "Heavy Duty".As I recall some slightly more recent Green Pennzoil ads used to say HD also meant High Detergent.

http://chevy.oldcarmanualproject.com/chevyowner/50om10.htm

Of course a frugal owner would likely use whatever was cheapest.

[Hallabutt]

This subject comes up rather regularly. The information is readily available for anyone willing to do a ten minutes of research from the forum data base. The information that I posted years ago was from a lengthy article put out by Valvoline. I'm no expert but the information spoke to me. I use detergent oil in all of my cars, some of which started life with ND oil, and have for forty years, with no deleterious effect.


I don't know why I get immersed in these discussions but... I also want to make it clear that the information that I'm responding with is thirty years old, so don't shoot the messenger. I'm not going to go to the wall over this. Thirty or more yeas ago I read a long article from Valvoline, regarding modern motor oils. The article covered the evolution of motor oil as it pertained to the advances made subsequent to the early 50's OHV cam shaft problems, modern oil's limitations and the misconception regarding the term detergent.

The article indicated that the addition of zinc and phosphorus left a sacrificial film on reciprocating parts which decreased wear. This was prior to the removal of those two elements, because of cat. problems.

The part of the article that I wanted to respond to, was Valvoline's statement the detergent oil does not remove slug inside an engine. They indicated that detergent was an unfortunate marketing term, used because of the popularity of the new technology (detergents). They suggested that a more appropriate, descriptive term would have been dispersant. It in affect, holds the small particulate matter, too small the be filtered out, in suspension until it is drained out at oil change. In other words it stopped or slowed down the settling out process that causes slug.

Over time the detergent package deteriorates. As I understand it, synthetic motor oil contains more sustainable "detergent" packages, and because modern engines are cleaner running with closer tolerances, oil change intervals can be extended. The process has not changed it's just that molecular structure that has changed and the "detergent" (disperant) package has become more long-lived, more suitable for newer engines.

[345 DeSoto]

Hallabutt - That was about the best explanation I've ever heard on modern oil. It cleared up a few questions I've always had, about modern oil. Thanks...