oil detergant or non det.

[jan bogert]

no oil filter, '41/42 flathead stock it was flushed out need to oil change, detergant or non det. what do ya think?

 

[46ford]

Flushed out? Did you drop the pan and clean it out? If so, modern oil should be OK.

 

[jan bogert]

not sure, when i got it took out the drain plug, and a cleaning agent ONLY came out about a pint of it. when i took off the intake, and heads it was super clean inside

 

[Brendan]

when i took the oil pan off my 36 it took me 2 hr to clean it out! the motor that i had in my truck was worn out, so i ran Castro oil 20-50 because i had no oil presser. ran it that way for 2 years and had no trouble

 

[46ford]

I always drop the pan and clean it before running an engine. These engines get an amazing amount of sludge over the years. I've heard horror stories about detergent oil breaking crud loose etc but not sure if they're true.

I dropped the pan in my '46 with the engine in the car... not too bad of a job. And you get to replace the pan gasket too... I hate leaks!

 

[paul2748]

Go with detergent. Might as well use the best. 20/50 Castrol or 15/40 Rotella T.

 

[Barry WNY]

The screen in the pickup is so important. I have one that is plugged with varnish. Clean the pan & replace the screen, you can tell if it's sludged. If so go non detergent. My brother & I Got a cheap Corvair did a "real good" oil change on the gunky motor, was toast in 3 days, shoulda stayed with recycled ND as was used to.

 

[flatjack9]

Absolutely use detergent oil.

 

[Forddraggin]

The Flathead im running in my car now is a 52,and when i got it i took oil pan off and got all the sludge cleaned out,cleaned the oil pump pickup screen and put all new seals in motor.After all that i filled up with 15-40 motorcraft oil.I have had good oil pressure and no problems since and have put around 5,000 mile on it.I made sure that after i put a 100 or 200 miles on it i changed because there is still sludge that will break down.I have several cases of non-detergent but chose not to use.

 

[jkeesey]

Unless you pull the pan I wouldn't use detergent, especially without a filter.

 

[garrisonm89@yahoo.com]

Detergent or Nondetergent has been the most hashed over question on the forum sites. You'll never get a definitive answer to the question. You have to understand that the people on the Ford Barn are all experts and still they can't give a definitive answer. One guy will have a valid answer for running nondetergent and the guy standing next to him will present as good an argument for running detergent. This debate has been going on since the invention of multiple viscosity detergent oil. The answer is; make your own decision on what you think is right based on whatever knowledge you can glean from your resources and you'll never be wrong.

 

[Old Henry]

In case some don't know the difference between detergent and non-detergent oils:

Detergent Motor Oil

Motor oil detergents were introduced in the 1950s. The concept adjusts for the failings of oil filters by attaching to those particles too small to get caught in filters. Instead the detergent holds the particles in the oil so they don't deposit on engine parts and cause hot spots. These particles are what makes the oil turn darker. These tiny particles do not harm your engine. If the oil is used for too long, however, it gets saturated, can't hold any more particles, and, in short, can't do its job. Then the particles start sticking to the engine interior. Thus, flushing out old oil regularly helps maintain the cleaning process and the benefit of the detergents.

Non-Detergent Motor Oil

Given the emphasis on keeping engines clean, most dealers and mechanics use motor oil with detergent. It can be a challenge to find a place that does oil changes with non-detergent motor oils. Many of the common non-detergent oils are instead used in appliances that run on gas, such as lawnmowers and tractors. Two-stroke oil would be another common non-detergent oil, mainly used in engines in motorcycles and watercraft.​

The Dark Oil Myth

Dark oil does not indicate the need for an oil change. The way modern detergent motor oil works is that minute particles of soot are suspended in the oil. These minute particles pose no danger to your engine, but they cause the oil to darken. A non-detergent oil would stay clearer than a detergent oil because all the soot would be left on the internal engine parts and would create sludge. If you never changed your oil, eventually the oil would no longer be able to suspend any more particles in the oil and sludge would form. Fortunately, by following the manufacturer's recommended oil change interval, you are changing your oil long before the oil has become saturated. Remember, a good oil should get dirty as it does it's work cleaning out the engine. The dispersant should stop all the gunk from depositing in the oil pan.

Read more: Detergent Vs. Non-Detergent Motor Oil |
http://www.nordicgroup.us/oil.htm#Detergent

In all of my studies of oils the only logical reason I have ever heard for using non-detergent oil is when breaking in a new engine so that the metal particles being rubbed off of the surfaces during break-in do not suspend in the oil and cause further wear and damage to the engine and can be flushed out with the first oil change after a very short time. Otherwise, all that I understand indicates that detergent oil is best for the reasons given above. Such would seem especially so for an engine without a filter.

I think it is a myth that detergent oil breaks down sludge. Such myth probably comes from the idea that detergent we use in laundry etc. is to break dirt away from the surface it's stuck to. But, I have not read any actual scientific studies that supports such myth. As the above information explains, the detergent additive only causes a suspension of particles already in the oil; nothing I've read says anything about releasing particles (particularly sludge) from the surface of parts it's already stuck to. Sludge is what happens when you don't use detergent oil. Instead of the particles staying suspended in the oil and flushed out when it's drained, the particles stick to surfaces, particularly the oil pan. So, if you don't want sludge, use detergent oil and change it regularly. If you already have sludge, detergent oil is not going to "break it loose" or clean it out.

I had read that running kerosene through the engine can loosen sludge. I tried it. It may have loosened it a bit but there was just no substitute to scraping it off and out. (That was after my engine hadn't run for 31 years.)

 

[More Dust than Rust]

I'm not sure the oil companies and their high dollar marketing campaigns are going to like that evaluation (although I agree). Seems like they all have a magic oil blend, and pictures to prove, that their oil will make an old engine like new inside. There actually is some science to it and standardized tests to determine how much deposits are formed in an engine that has large amounts of blowby intentionally introduced (to Prof. Henry's point of suspension). The science of "sludge" removal seems to be a thing of internal company tests and before and after pictures.

Are any of us going to be putting that many miles on these engines between oil changes that it really matters? I bet out of love and boredom most of the guys here change their oil way more often than the original owners would have even thought of and they were running much less efficient lubricants.

Like others have said, drop the pan, clean it out, maybe throw a coat of paint on it, replace the gasket and refill with whatever you feel comfortable with. Whatever winds up going in is going to be a better lubricant than some of the stuff your engine has likely had in it before.

 

[JWL]

Flatjack and Old Henry have it right. Detergent oil is the only logical choice. I like Valvoline but any, brand name, modern oil is much better than anything available when your engine was new. Each guy has his personal brand preference and it is not a point for argument.

 

[oldblue]

Use detergent and change oil often . Oil is cheap engines cost.
Allan

 

[Uncle Bob]

Detergent or Nondetergent has been the most hashed over question on the forum sites. You'll never get a definitive answer to the question.

Disclaimer: Comments made here are not intended to embarass or attack any forum member in this thread or others of similar subject, just trying to be informative and use certain phrases as comparatives. Also might use a couple unfamiliar terms just to see if anyone takes the time to look them up to expand their vocabulary. (Yes, I'm feeling a bit devilish this morning)

Garrison is correct that this subject is "beat to death", here and elsewhere. The second sentence quoted is a product of internet annonmity. We don't always know the credentials of the poster. A definitively correct statement only has authority if the reader has the knowledge to recognize accurate from inaccurate. There have been two or three folks on this forum who have professional knowledge of lubricants, to my knowledge, perhaps there are more, but you don't often see posts anymore because, functionally, incorrect info has equal perceived value to correct.

Prof. Henry has done a very nice job of explaining reality, though I would guess he's not been trained as a tribologist. He's likely an inquisitive and detail oriented soul, and has taken the time to inform himself. I'm pleased that he took the time to debunk the "dark oil" myth. One thing to keep in mind, the term for the "cleaning" portion of the additive package within the industry is "detergent/dispersant". It's the dispersant portion that should be more prominant as described in Henry's "suspension" commentary. The one statement that might be off is the idea of metal particles suspended at break in. Keep in mind, crankcase oils have a menu of additives for multiple purposes, not just detergents alone. Only very light, microscopic metal particles MIGHT be suspended. Any large enough to do damage would be too heavy for the additive to affect. More likely, the concern is from the anti-wear additives, such as ZDDP in older formulations, potentially not allowing the, for example, rings to "wear in/seat". That in itself would be another involved discussion.

Any experience with older sludge build up being dislodged is less likely the "fault" of the d/d additive, more likely from fluid flow action. Particularly if the oil changed to is a multi-grade. The multi-grade is more fluid at lower temperatures (start up and warm up), and would flow faster, potentially knocking build up loose. Similar to Henry's kerosene example, it might break loose sludge that's marginally bound to the mass, but not the tightly agglomerated stuff.

 

[Marv]

Back in 1952 my father bought a 1950 Nash Ambasador with 21,000 mile on it. Where he was working at that time had a salesman show up pushing Mobile oil, and telling how great it was and how it cleaned your engine. Dad thought it sounded like a good idea ,so he bought a case of it and changed oil in the Nash. It worked well and cleaned the engine, however the previous owner had used nondetergent oil in it. The engine lasted a week and blew up. Dad tore it down and overhauled it, because that detergent Mobile oil had cleaned all the gunk out. The same hapened to a lot of the companies equipment also. After that, Mobile oil in that location, was known as bearing removal oil and they switched brands of oil. My self i use Castrol oil in my cars and Pennsoil in my deisel tractors. Marv

 

[Old Henry]

Prof. Henry has done a very nice job of explaining reality, though I would guess he's not been trained as a tribologist.

Had to look that one up.

Tribology: The science and engineering of interacting surfaces in relative motion. It includes the study and application of the principles of friction, lubrication and wear. Tribology is a branch of mechanical engineering.

Thanks for the new vocabulary word.

You are right that "He's likely an inquisitive and detail oriented soul, and has taken the time to inform himself." When I graduated from law school eons ago I was surprised to discover that I had not learned as many answers as I had learned what questions to ask and how to find the answers. I have, ever since, been eager to learn what I do not know and share that knowledge with others. This forum gives me just one more outlet for that.

Thank you all for asking questions. If I do not know the answer from my personal experience I will try to find a very well documented (supported with evidence and scientific testing) one to share.

 

[Old Henry]

it might break loose sludge that's marginally bound to the mass, but not the tightly agglomerated stuff.

ag·glom·er·ate (

-gl

m

-r

t

)
tr. & intr.v. ag·glom·er·at·ed, ag·glom·er·at·ing, ag·glom·er·ates To form or collect into a rounded mass.

adj. (-

r-

t) Gathered into a rounded mass.

n. (-

r-

t) 1. A confused or jumbled mass; a heap.

2. A volcanic rock consisting of rounded and angular fragments fused together.

[Latin agglomer

re, agglomer

t-, to mass together : ad-, ad- + glomer

re, to form into a ball (from glomus, glomer-, ball).]

I love it. Keep 'em coming.

 

[Barry WNY]

Back in 1952 my father bought a 1950 Nash Ambasador with 21,000 mile on it. Where he was working at that time had a salesman show up pushing Mobile oil, and telling how great it was and how it cleaned your engine. Dad thought it sounded like a good idea ,so he bought a case of it and changed oil in the Nash. It worked well and cleaned the engine, however the previous owner had used nondetergent oil in it. The engine lasted a week and blew up. Dad tore it down and overhauled it, because that detergent Mobile oil had cleaned all the gunk out. The same hapened to a lot of the companies equipment also. After that, Mobile oil in that location, was known as bearing removal oil and they switched brands of oil. My self i use Castrol oil in my cars and Pennsoil in my deisel tractors. Marv[/QUOTE)

What I was saying, if it's gunky and you use high tech oil itwill loosen up allthat crud & run it through everything. Not so bad parrifin based north east parrafin based stuff. I had a gunky LTD from texas with texaco oil change stickers, 130000 mi sludge was crunchy crusty. Ran it 3 years on ND no way did I want that loosening up and traveling through.