detergent oils

[broker-len]

I just had my 32 PA, plymouth, motor rebuilt,,,it has pored babbit bearings,,,I was told that the modern detergent is not good for this material,,,I do have friends that use it with no problems,,,,any feed back ?????--bobnroman@yahoo.com

[ply33]

New one on me. Never heard that detergent oil affected babbitt and it sounds like a bunch of hooey to me. If I recall my decades old and never used engineering class that covered plain or journal bearings, all of them use babbitt or equivalent material. Modern thin shelled inserts simply have a very thin layer of the material. Seems like if the oil was not good for babbitt it wouldn't be good for modern bearings either.

Best reason I've heard for not using "modern detergent" oil is for fear of loosening up old crud in the engine and sending it on a destructive path through the engine. If you engine has been rebuilt then that is not an issue.

I firmly believe that modern oil is far better than what was available way back then and use a multi-viscosity detergent based oil in my 33 PD Plymouth.

[Guest 36chev]

Ply33, I concur. Been using 10w30 in my newly rebuilt 36 Chevrolet engine with NOS babbitt rods and thin-shell modern insert main bearings. Some say to use 5w30 in a newly overhauled engine, and I may consider switching to that when get ready to change the oil soon. Babbitt bearings, at least on the connecting rods, have closer tolerances than inserts.

I think I've heard the argument that modern detergent oils keep particulates suspended in them, so that some claim that is an issue for softer babbitt in unfiltered systems. But I will continue using multi-grade detergent.

[ply33]

...I think I've heard the argument that modern detergent oils keep particulates suspended in them, so that some claim that is an issue for softer babbitt in unfiltered systems. But I will continue using multi-grade detergent.

His Plymouth should be equipped with an oil filter. At least it had one when it left the factory. All Plymouths from the 1930 (engineering code 30-U) through at least 1934 (engineering codes PE and PF) were equipped with oil filters as standard equipment. They dropped the filters, or rather made them an option, on the lower priced "standard", "business" or "Roadking" versions later in the 1930s.

[jpage]

I have used high detergent multi-viscosity oils in my Model A for 16 yrs. with no problems. There are several falicies out there about these oils ,the number one is that HD oil will loosen old sludge and ruin the engine. Hd oils will not remove the old sludge ,but it will prevent the formation of new dirt deposits,another is that they suspend particulates. That is partially true(that's what helps inhibit the formation of sludge )but the oil filter will filter out the particles and the oil does suspend acids,water, and other damaging chemicals that can damage babbitt bearings that non.detergent oil will not. Another falicy is that oil breaks down. It does not ; motor oils can be reused after they are scrubbed of dirt as it is done all the time in the hvy. duty industry. The multi-viscosity will also help as it does not thicken with the lower temps. as non-det. will. I don't think you'll have any problems!

[NTX5467]

Oil might not "break down", but the additive package will depelte over time, which can also resuslt in the TBN of the oil decreasing to zero (if not changed often enough) and become acidic. I don't recall any non-detergent oils ever being multi-viscosity, as detergent oils could be (starting in the earlier 1960s) . . . which would explain the multi-vis detergent oils offering better oil flow at start-up than ANY single-viscosity oil might (unless it's 10W or so).

For many users, the decrease in TBN will not be an issue as it might for constant-use fleet vehicles (as in delivery vehicles or OTR trucks).

I'd be more concerned if the rubber seals/gaskets used might be compatible with synthetic motor oil? Plus sufficient zddp or other similar anti-wear additives. But as long as you can get Delo400LE or similar in a 10W-30 viscosity or so, that'd probably be good enough.

But until you get some miles on it, you might use SAE30 with some zddp additive for good measure. That'll give you a baseline to see how things are going to be, with respect to oil consumption and such. After that time, then venturing off to a multi-vis oil could then indicate how well the engine will tolerate it. In prior times, the recommendation to not use a multi-vis oil for break-in was due to the fact that the single-vis oil was considered to be more stable in how it acted, viscosity-wise. In more recent times, I believe that even the OEMs put multi-vis oil in a the engine plant.

For a normal rebuild, though, using a single-vis oil first can give you a baseline for oil consumption and such. End result is that if there is "more" oil consumption than you might like, it can't be blamed on the multi-vis oil.

Just some thougths,

NTX5467

[HarryJ]

I run 10W30 detergent in my 31 PA.

[broker-len]

Thanks for all the good info,,32 PB was the first plymouth that had an oil filter,,,,and as in later cars it is not full flow, so very little of the oil gets cleaned,,I was using detergent oil in the PA but like I said, the rebuilder told me that the babbit in poured bearing is not the same as in inserts and the detergent will harm it in time

[ply33]

Thanks for all the good info,,32 PB was the first plymouth that had an oil filter,,,,and as in later cars it is not full flow, so very little of the oil gets cleaned,,I was using detergent oil in the PA but like I said, the rebuilder told me that the babbit in poured bearing is not the same as in inserts and the detergent will harm it in time

Hmmm. Parts book shows oil filters for 30-U and PA too. Perhaps because you are listing your car as a "32 PA" it is actually a "thrift model" that was built after the PB was introduced. Maybe those did not come equipped with filters, I'll have to see if the parts book lists engine numbers on the filter usage.

On a bypass filter only a little oil is filtered at a time, but all the oil will be filtered within a few minutes. And because you don't have to keep the pressure drop across the media very low a bypass filter can filter out smaller particles than a full full filter. So don't sell them short.

[Guest Foggy norm]

Okay, I'll plead dumb....NTX5467, had concern's about the synthetic oil on seal's etc. It's my understanding synthetic oil is not 100% synthetic, but a mix with conventional oil. Also, wasn't zddp banned from use? I've considered using synthetic since it's a mix and won't require flushing the motor, any opinion's about synthetic.

[jpage]

I might be wrong but I think that the old units.whether sealed or replacement,were full flow. all the oil passes directly through the filter. What happens with these filters is as the filter becomes blocked by dirt the oil flow slows possibly starving the engine for oil which neccessitates regular changes. Modern oil filters are by pass type,they have a valve inside that allows oil to flow without restriction when the filter itself becomes clogged. Even dirty oil is better than no oil!

[ply33]

I might be wrong but I think that the old units.whether sealed or replacement,were full flow. all the oil passes directly through the filter. What happens with these filters is as the filter becomes blocked by dirt the oil flow slows possibly starving the engine for oil which neccessitates regular changes. Modern oil filters are by pass type,they have a valve inside that allows oil to flow without restriction when the filter itself becomes clogged. Even dirty oil is better than no oil!

The filters on Plymouths of that era have an input from the main oil gallery and output to the oil pan. Starting in late 1933 they ran the output through a spool valve that was part of the oil pressure relief system that was setup for blocking flow through the filter if the oil pressure dropped too low. These are true bypass filter systems as the oil going through the filter bypasses the engine. If the media gets clogged the engine still gets oil as the oil going through the filter is on its way to the sump and not the engine.

Full flow filter systems are in line between the oil pump and the main oil gallery. And to allow oil into the engine if the filter becomes clogged (actually just so restricted that the pressure drop across the media is too large) the system has a bypass valve built in. In modern spin on oil filters that bypass valve is part of the throw away spin on filter. A couple things to remember on this: To keep the pressure drop across the media low the full flow filter cannot remove smaller impurities. And because the filter is designed to be inexpensive some manufacturers use bypass valves that are either ineffective or leak. If leaking then the filter is not doing much filtering at all even if new. Do a web search on oil filter quality or oil filter tear down...

So the word bypass is used in both cases but for different reasons.

[Rusty_OToole]

Thanks for all the good info,,32 PB was the first plymouth that had an oil filter,,,,and as in later cars it is not full flow, so very little of the oil gets cleaned,,I was using detergent oil in the PA but like I said, the rebuilder told me that the babbit in poured bearing is not the same as in inserts and the detergent will harm it in time

This is another myth. All the oil does get cleaned, just not all at once. It all goes through the filter in the course of an hour's drive and it gets filtered more effectively than in a full flow filter.

There was some discussion of this point on another board. One person asked about cleaning the dirt and sludge out of the filter housing when changing the filter. If the filter was not effective, how did it get full of dirt and sludge? All the dirt in the filter was dirt that would otherwise have been in the engine and in the bearings.

[NTX5467]

Okay, I'll plead dumb....NTX5467, had concern's about the synthetic oil on seal's etc. It's my understanding synthetic oil is not 100% synthetic, but a mix with conventional oil. Also, wasn't zddp banned from use? I've considered using synthetic since it's a mix and won't require flushing the motor, any opinion's about synthetic.

First . . . zddp was NOT banned, it's still in motor oil, just at lower levels than in prior times. The "SL" designated oil was the last one to have a good level of zddp in it. There are some Euro diesel oils, Castrol Synthetics and Mobil 1 Synthetics, that are "SL" and have 1000ppm of zddp in them. The normal non-syn diesel oils in 15W-40 (Delo 400, Rotella T) usually have about 1300-1400ppm zddp in them (even the current "SN" gasoline rated diesel oils!!!).

Many years ago, Mobil had some litigation against Castrol terming their "synthetic" oils as "synthetic" (or similar). This was well before the latest group of Castrol's synthetic oils (The Edge, and such) came out. Even within the synthetic oil spectrum, there are different kinds of synthetic formulations. "Ester-based" is one (remember esters from high school chemistry . . . that "sweet banana" smell? Motul brand synthetic oils have that same strong smell when you open a bottle . . . or at least they did a few years ago. From what I understand, ester-based synthetic oils have greater tendencies to liquify sludge for cleaning purposes. I also believe that Mobil 1 OEM viscosity formulations have some esters in them, but not enough to get that strong banana smell.

The issue with rubberized seals is that some rubber compounds weren't formulated with durability in a synthetic oil world as part of their design criteria. After time, the seals will become softer and compromised enough to leak. Doesn't matter if it's engine, transmission, or rear axle seals. At one time, Valvoline had a bottle recommendation to not use their synthetic oil in vehicles made prior to 1970 (or thereabouts) . . . obviously due to the seal issue. But then several posters in the Buick forum noted that they had used syn oils with no problems, in their older Nailheads and such. Obviously, a variable situation, too.

"Blended synthetic" (which is what Mobil claimed "the other brand" really was as Mobil 1 and Castrol Syntec both claimed to the "full synthetic" motor oil) is an acknowledged blend of (mainly) "dino" base stocks with a little "syn" base stock added in for certain enhanced characteristics. Only thing is that the amount of each is never specified--and it varies from brand to brand. Still, blended syn oils are an upgrade from non-syn oils. Delo 400LE doesn't claim to be a blended syn oil, but their online videos indicate that their "ISOSYN" technology "gives synthetic performance without the synthetic price".

You can go to the www.bobistheoilguy.com website, look for "Forums" and "Virgin Oil Analysis". That's where people have had oil samples checked to see what's in them. About 50 pages of oil analysis postings, covering several years in time.

Take care,

NTX5467

[broker-len]

going back to plymouth oil filters I have official pictures of 28 and 30 U ,,no filters shown also none in PA picture PB does show a filter,,,,my PA does have the small plug for the filter return in the back of the block casting-------------BR

[ply33]

going back to plymouth oil filters I have official pictures of 28 and 30 U ,,no filters shown also none in PA picture PB does show a filter,,,,my PA does have the small plug for the filter return in the back of the block casting-------------BR

I guess I should just ignore the entry in the 1928-34 Plymouth Master Parts List that says

Group 10-C -- Oil Filter

Cartridge assembly -- 30-U, PA, PB, PC [...] ..... 324271

[herm111]

Thanks for all the good info,,32 PB was the first plymouth that had an oil filter,,,,and as in later cars it is not full flow, so very little of the oil gets cleaned,,I was using detergent oil in the PA but like I said, the rebuilder told me that the babbit in poured bearing is not the same as in inserts and the detergent will harm it in time

Mr. Broker, your rebuilder has a lot to learn! If you ever have bearing failure, It will, and can be many reasons, but detergent oil will NEVER be one of them. I have heard that saying for many years, and it is passed around by people that plain don't know, and never really think about what they are saying, but of them all, they have never had any experience with it, just pass it on as truth!

Lastly, there are only two kinds of babbitt, Lead, and Tin. Tin base was always used when the cars were made. Lead was used by some rebuilders during the war, because the Goverment had most of the Tin, and like today, tin was much higher then lead.

Now the only way I could think that your rebuilder could have different kinds of babbitt, is if he had some body pour tin in the rods, and got lead after market insert bearings.

I said, the rebuilder told me that the babbit in poured bearing is not the same as in inserts end quote.

I think you are referring to poured bearings, that are rod bearings, the fact is Inserts are poured also, so I don't see a Distinction.

Boy, never seen lettering like this before.

Thanks Herm.

Edited March 9, 2012 by herm111 (see edit history)

[Guest Foggy norm]

NTX5467...............thanks!

HERM......I do that to!

[broker-len]

My PA has mains that were poured and line board ,,,not shure about the rods,,,my understanding is these are different that inserts that are standard size and just placed in bearing caps,,,as stated,, for some reason am being told that the babbit material is not the same and affected by the detergent ???????

[Restorer32]

The shop that does all our babbit work uses the same bearing material as used in modern diesel engines. The still pour around 1500 sets of Model A Ford bearings per year. Actually there are at least 3 types of babbit, lead, tin and coppered tin.

[Matt Harwood]

Don't bother with synthetic blends--the disadvantages of both with no real advantages. It costs more than regular oil, but still has the drawbacks of regular oil. Why bother? Go full synthetic or stay with conventional. I'm a fan of synthetics, but because their molecules are different (straight chains of carbons rather than clusters, which is what makes them "slipperier"_), they tend to work their way through some seals and imperfect surfaces. Old cars may see increased leaking with a synthetic if older gasket materials are used, such as cork. In essence, the synthetic can find its way through smaller holes than regular oil, causing leaks. Modern synthetics won't damage the gaskets, but people mistakenly blame the synthetic for damaging the gaskets when in reality it's simply slipping through holes that conventional oil can't.

I use Brad Penn oil in my '29 Cadillac, as it has a the ZDDP. Personally, I think the zinc issue is way over-blown (just like the loss of lead in pump gas) but since this oil is specifically formulated for collector cars, I use it. I also get a discount on it when I buy in bulk, which we do at the dealership.

Any modern oil is vastly better than the oils from when the cars were new, so use whatever you like--even the ultra-cheap stuff at Wal-Mart is better than anything it had when it was new, and none of it will harm your bearings.

Hope this helps.

[NTX5467]

Even conventional oils can "wick" through rubber/cork gaskets -- some more than others.

It was somewhat common to have valve cover oil leaks on many engines in the '60s and later. Some considered it a valve cover retention issue, which it could have been (the "spreader bar" valve cover stud kit GM had for the small blocks in the middle 1980s, for example; Chrysler B/RB engines getting one additional valve cover bolt hole in the earlier-middle 1960s), but nobody asked "What brand of oil are you using?" back then.

A friend had a '69 Dodge SuperBee 383 that he took good care of and worked on himself. He started using Castrol GTX motor oil and had some colorful language about it. He couldn't get the oil leaks from his (known good and flat) valve covers to stop. I'd used the same oil in my '77 Camaro 305 with no issues of that nature.

I posed the question to my machine shop operative. He noted that some oils "wicked" through the cork gaskets more than others. Once the wicking started, no real way to stop it other than new gaskets. He, being an old drag racer, was partial to Valvoline, but bought whatever was on sale (when he needed some oil for his personal truck) at the local chain auto supply near his shop back then. He confirmed the wicking tendency of some oils was greater than others. If one leaked on his truck, he went to another brand and didn't bother to change the gaskets. As he noted, some oils get into the smaller nooks and crannies better than others. IF that makes them better oils, that can remain a question for ponderances.

In order to end the wicking tendencies, I started putting a thin layer of black silicone on the valve cover gaskets (and other gaskets I might be changing) and let it dry before I replaced them. A thin layer on all sides. This way, no way for the oil to get to the base gasket itself AND it was much easier to clean off later on (I spent waaayyy too much time scraping off the "yellow stuff" adhesive which did nothing to stop the wicking tendencies on valve cover gaskets!).

Enjoy!

NTX5467

[herm111]

The shop that does all our babbit work uses the same bearing material as used in modern diesel engines. The still pour around 1500 sets of Model A Ford bearings per year. Actually there are at least 3 types of babbit, lead, tin and coppered tin.

No body poures anything called Copper Tin! Some shops pour Lead babbitt which shouldn't be used in Automotive bearings. Most all U.S. car manufacturing Compananies Used Tin Base Babbitt, Grade No. 11.

You might be thinking of some early V-8 Ford bearings that were Copper- Lead lined inserts, that did not work out very good at all. But that is factory inserts, not something you pour.

Herm.

[herm111]

My PA has mains that were poured and line board ,,,not shure about the rods,,,my understanding is these are different that inserts that are standard size and just placed in bearing caps,,,as stated,, for some reason am being told that the babbit material is not the same and affected by the detergent ???????

Nothing to worry about, Mr. Broker, just an old wives tale.! Thanks Herm.