What oil are you using.

[frijolito]

4 minutes ago, T120 said:

Great photo of your Plymouth...

 

Thank you

[Bryan]

Here's a long read ...  MOTOR OIL ENGINEERING TEST DATA | 540 RAT - Tech Facts, NOT Myths (wordpress.com)

[Sniper]

50 minutes ago, Bryan said:

Here's a long read ...  MOTOR OIL ENGINEERING TEST DATA | 540 RAT - Tech Facts, NOT Myths (wordpress.com)

 

 

Interesting, but he really needs an editor or something to put this into a format that is more user friendly.  He confirms several of my anecdotally developed thoughts.  

[Young Ed]

I seem to be the oddball here I run 10w40 in all my stuff.

[wallytoo]

i run 15w-40 in the 251.

[wagoneer]

Maybe I missed something here, but the manual calls for 20W oil, and only under high speed driving/high oil consumption use 30W. I've been running 20w-50 generally though I guess now I'm about to change the oil anyway, I may go for a lighter weight. I'm putting straight 10w non-detergent in the trans, but sounds like 10w-30 should be sufficient. 

 

I find it amazing that there are any engines out there that are still running non-detergent because of historical oil/sludge build up. Here in North Carolina, probably could do 10w straight year round though I'd be curious about those up in the colder climates have ever tried diluting their oil with kerosene (per the manual).

 

 

[Sniper]

Not sure what manual you have, but mine calls for 30w oil.  It only deviates from that if the temps get cold.

 

Now since my car predates multi weight oils there is no recommendation for them.  However, the manuals for 55 and newer do.  54 is when multi weight oils came on the market.

 

None of the recommendations calls for 20w50 though. pic out of the 55 FSM

 

 

[wagoneer]

Chrysler Service manual  - C38 - p296

 

 

 

 

I haven't seen 20w-40 so I went with 20w-50.

 

[Sniper]

Odd, never saw that before.  You realize that 20w50 negates the reasoning Chrysler states for running a 20w oil when your engine is warmed up.

[kencombs]

15w40 is a common oil recommended for a lot of diesels.   I've used it a lot as I had a diesel truck and small tractor.  Still have the tractor.  It is Very high detergent due to the sooty diesel use. Since it was always on hand, it got used in old engines too.  Will probably be the oil of choice for the 56 when it goes together.

 

I pay little attention to brand, just specifications.  If it meets the published criteria, I'll use it.  I've been driving since '59, no oil related engine failures. But do remember the sludge from certain oils and no PCV systems.   my 230 will have one! much more important than brand IMHO.

edit:  BTW if you have some time to kill,  lots of it, go here:   https://bobistheoilguy.com/forums/

more oil info than you'll ever need.

Edited January 10, 2022 by kencombs

[wagoneer]

2 hours ago, Sniper said:

Odd, never saw that before.  You realize that 20w50 negates the reasoning Chrysler states for running a 20w oil when your engine is warmed up.

 

I must admit my understanding of the multigrade weights and it's impact isn't as technically deep as I would like, but it's improving.  What's key to this discussion is also that the multi-grade oil changes behavior at certain temperatures which our engines in theory shouldn't get to -- 100 C/212 F, and some, depending on the climate get to during winter time.

 

 

Seems to me according to the below document - a 5w20 would be most appropriate per the manual for the engine given the climates we generally operate in, and drive our antique vehicles, and that most are garaged. 5w is probably close to what you get when mixing kerosene in 10w to thin it out a bit.

 

A single weight 10w for the transmission makes all the more sense given its significantly lower oil viscosity necessary for the valves and check balls to properly flow when changing gears. Makes all the more sense. 

 

@Sniper Reading this again, a 20w50 makes little sense now, and my next oil change will likely be 5w20.

 

 

https://addinol.de/en/products/lubricants-for-the-automotive-sector/engine-oil/multigrade-oil/

 

 

 

 

 

Edited January 10, 2022 by wagoneer

[Sniper]

That website you linked is confused I think or I am.  In the table they claim that the disadvantages of multigrade oil are "Faster oil aging and Accelerated loss of the original viscosity"

 

In the paragraph immediately below that table they claim "By adding additives, modern multigrade oils have a wide operating temperature range in which the viscosity remains stable. In addition, increased oxidation stability guarantees a long service life of the oils. For this reason, multigrade oils are also designed for longer oil change intervals and can be driven up to 60,000 kilometers as longlife oil."

 

Seems to be saying the exact opposite.

 

As for the temperature you mention, oil can indeed meet and exceed 212F, it depends on where the temperature is measured.  Part of the oiling systems job and one that is not usually mentioned, is to cool parts as well as lubricate them.  The bearings run way hotter than the oil or coolant does and without the oil flowing thru them they would overheat and melt in short order.  So while the sump in the pan isn't 212 that is not the only place oil is hot and where it is hottest (the bearings) it is also where viscosity is most important. 

 

 

 

 

[kencombs]

Regarding the web site info above I think they just did a bad job of presenting the info.   Multigrades do change viscosity over time.  Much worse years ago but very little with the latest formulations. 
way back in ‘60 I worked at a service station.  The owner’s wife drove 58 Cadillac.  Multi-vis oils were fairly new and one of the market leaders was phillips66 Trop-attic.  That was what was used in the cad.   At 1500 miles it would be at the full mark.   At 2500 it would be down a pint.  At 3000 when it got its oil changed, down a full qt.  So oil burning definitely increased with mileage.  

[kencombs]

Regarding the web site info above I think they just did a bad job of presenting the info.   Multigrades do change viscosity over time.  Much worse years ago but very little with the latest formulations. 
way back in ‘60 I worked at a service station.  The owner’s wife drove 58 Cadillac.  Multi-vis oils were fairly new and one of the market leaders was phillips66 Trop-attic.  That was what was used in the cad.   At 1500 miles it would be at the full mark.   At 2500 it would be down a pint.  At 3000 when it got its oil changed, down a full qt.  So oil burning definitely increased with mileage.  

[wagoneer]

Viscosity in the chart above is measured in  Centistokes (mm^2/s). Effectively, how long it takes for a liquid to flow at a particular temperature (100 C in SAE).

 

https://www.machinerylubrication.com/Read/411/oil-viscosity

 

Because the flow-rate is governed by resistance of the oil flowing under gravity through the capillary tube, this test actually measures an oil’s kinematic viscosity. The viscosity is typically reported in centistokes (cSt), equivalent to mm2/s in SI units, and is calculated from the time it takes oil to flow from the starting point to the stopping point using a calibration constant supplied for each tube.

 

Stating an oil’s viscosity is meaningless unless the temperature at which the viscosity was measured is defined. Typically, the viscosity is reported at one of two temperatures, either 40°C (100°F) or 100°C (212°F). For most industrial oils, it is common to measure kinematic viscosity at 40°C because this is the basis for the ISO viscosity grading system (ISO 3448).

Likewise, most engine oils are typically measured at 100°C because the SAE engine oil classification system (SAE J300) is referenced to the kinematic viscosity at 100°C (Table 1). Additionally, 100°C reduces the rise of measurement interference for engine oil soot contamination.

 

 

 

 

[Bryan]

On 1/8/2022 at 6:56 PM, Bryan said:

If you had the engine rebuilt, asking the oil question will start a chain of 30W vs 10-30W comments for the next week.  

How could I have known?  ? ? ?

[Sam Buchanan]

I'll warm up the popcorn popper......  ?

[Polsonator2]

Unless it is an old tired engine full of gunk there is no reason to use non detergent oil. Detergent oils came out in the early 50s, contrary to a lot of the common folklore you hear.  Your motor has most likely been using detergent oil since the 50s for sure.  This non detergent oil thing is a complete myth handed down by people who swore on it because their grandpa or dad did because of some hearsay bs legend. Most cars by the mid to late 50s have been using detergent oil from then until now or the day the car died.  If the car has sat in a barn or field since before the 50s then maybe..

 

Go to the 11:20 mark of this 1953 Chrysler Master Tech video for proof (they also highly recommend it for "hard driving", straight from Tech's own mouth): 

 

 

 

Personally I use 5w 40 rotella instead of 15w 40. And not because of the zinc, which I also believe is not necessary in a mopar flathead.  I do it because it gives me light weight cold starting like a 10w 30 and get the benefit of the 40 weight at high speed driving.  My rod clearances in my rebuilt 230 motor are .002 and mains are .0015.  If you are running factory clearances of .0005 to .0015 I would go with 10w 30.  If it gets thin when hot after a freeway run move to the 5w 40 rotella(unless you have leaks because its pricey).  If leaks try 10w 40.  If still thin when hot after a 10w 40 go 15w 40.  I only used 20w 50 after I spun a rod bearing and did a shade tree rebuild to get my previous motor back on the road.  It helped keep pressure up for another 10k miles or so but ultimately the bearings kept wearing out due to the crank not being taken out and reground. Now that I have a fresh rebuilt motor with polished fresh crank, I go for the lightest oil I can that does not thin out after a half hour freeway run.  If you are not spinning continually at 2800+ rpms like I am on the freeway I would again recommend 10w 30.

 

One last thing, no need to use a straight 30w oil either... see Sniper's earlier post in this thread that shows how 10w 30 was also recommended in the mid 50's manual once it was available. Very likely that most mopar flatheads ran from the mid 50's to now or when they died were also using multi viscosity oil...

Edited January 13, 2022 by Polsonator2

[soth122003]

I agree with the 10w30. It's what I use in my car, but I have the usual rear main drip. So, I fill it with 10w30 then as it leaks down over the next few months, i add a little 5w20. Why you may ask? Well I'll tell you. The oil I buy for my car comes in the 5 quart jug from wally world or amazon and the engine take 5 quarts, My wife's car uses 5w20 and I get it in the 5 quart jug, but her car only uses 4 quarts at the oil change. So the remaining 1 quart goes in my trunk and I use that to top oil between changes. Every 3000 to 4000 mile or yearly which ever comes first. So by that reckoning I use 8w27 by the time the oil change is due.

 

Joe Lee

[wagoneer]

@Polsonator2 I haven’t seen that video before but it has really good info .  For us it also makes a lot of impact since they primarily used the inline 6.

 

more food for thought but basically he says a couple of key things: 

 

  1. Research over the past years has shown that heavier oils are better as long as they don’t affect cranking ability and thus recommend 30 SAE and 20W.
 

 

 

 

 

2. interesting how the ML MM and MS service reference has gone away. But was key to the driving and recommendations guidance.

 

 

.

3. New engines use a straight 10W non detergent to help rings seat 

@keithb7 that may interest your new rebuild 

 

they recommend non detergent so rings will seat themselves Until the break-in period is over.

 

4. When they say 10W or 20W, does that mean it’s short form of 20-20W  so viscosity is consistent across the temperature range?

 

 

 

Edited January 13, 2022 by wagoneer

[keithb7]

I’ll consider short term SAE oil use for ring sealing. Yet that info is related to ring technology from back in the 50’s.  I am skeptical the new piston rings purchased today are made to the old standards?

[Sniper]

I see no evidence that any of the flathead piston rings are made to modern standards either. 

 

So I guess it's a coin flip. 

[wagoneer]

By the book (of Chrysler), this is the weight of oil to use the first 1000 miles:

 

https://www.lubriplate.com/Products/Fluid/Motor-Oil-Series/NON-DET-MOTOR-OIL-10W/NON-DET-MOTOR-OIL-10W/NON-DET-M-O-SAE-10W,-12-1-QTS/

 

 

The video couches the statement that “sometimes” rings don’t seat and cause more than normal oil consumption.
 

Seating properly requires wear and detergents prevent wear, thus they recommend no detergent ML oil to allow the wear. 
 

whether that is true anymore I don’t know. A lot of engines out there running detergent oil always.
 

 

I still don’t understand what SAE 10-W oil is different from say a SAE 10. The tech specs indicate temperature range is key.

 

seems it flows like a 10 all the time according to chart below.

I have heard or read elsewhere that there are benefits of multi weight oils due to polymers coating bearings or something. If multigrade wasn’t there before mid 50s then how did they come up with 10w(-10)

 

 

If you see excessive oil consumption after a 1000 miles, do as tech sez-> get an ML service.

 

 

Here is a detergent 10-W . Notice it's SJ quality oil and not sure why it meets SAE 30,40 too. This is a bit confusing but if you want 10W oil, you can have single grade detergent 10-W of a 90's vintage quality oil suitable for slightly older engines. 

 

https://shop.sclubricants.com/delo-400-sae-10w

 

 

 

 

A separate discussion from viscosity is API specification. 

 

Edited January 14, 2022 by wagoneer

[Sniper]

There is no ML grade oil anymore, unless you find something on a shelf in someone's garage.  That is a system that they replaced in 1981 with what we are using today.

 

SAE 10 is 10W, https://www.sizes.com/materials/engineOil.htm

The W only means it's a winter grade.  No one was specifying 10W for summer use, only winter, which is why the W was appended.  Has nothing to do with the advent of multi-viscosity oil.

 

Multi-viscosity oils have nothing to do with polymer coated bearings and everything to do with how thick the oil is at a specified oil temperature.  Straight 30 weight oil is very slow to pump in cold weather.  So thinner oils were specified for those climates.  Do a test.  Get a bottle of 30 and a bottle of 10w30, put them in the freezer overnight.  Next morning pour them out and see which flows quicker.  At those temps the 10w30 flows like a 10W oil, as it heat sup to operating temp is thickens up to a 30 oil.  That is all multi-viscosity oil means.

[Bryan]

On 1/8/2022 at 6:56 PM, Bryan said:

If you had the engine rebuilt, asking the oil question will start a chain of 30W vs 10-30W comments for the next week.  

How could I have known?  ? ? ?  Two more days everyone, we need two more days to fulfill my prophecy of 1 week!  ?

Edited January 14, 2022 by Bryan