MTFCA Forum

The last time I had this problem was back in the early 1960's. At the time the oil of choice was 30 wt. non detergent. with the variety of oil on the market now, what is the oil of choice? Should I use synthetic, detergent or non detergent and what wt. should I use? It used to be 30 wt. but what is recommended now? By the way, the engine is completely rebuilt and has not been started yet.
Thank you
Craig

Ask your engine rebuilder what oil to use. I am using good old 10w40 in my recently rebuilt engine.

Get ready for lots of comments!
Assuming you used some type of pre lube such as a light grade of oil, lubriplate, or STP with a light mix of oil or any thing else I would use 10w30 detergent oil.

And there will be other ideas about this too. There always is.
Whatever oil you use is way better than was ever put in a T engine at the factory in the Model T era.

I currently use 10W30 or 15WW40 conventional oil. However, conventional oil is becoming near extinct at WalMart, so I am considering using synthetic. My concern is the synthetic oil being too slippery with cotton bands. Several years ago I heard of this problem but I don't know how true it is.
Synthetic oil will robbbly work quite well with Kevlar bands.

Art Mirtes

I use full synthetic with Kevlar bands with no issues whatsoever, even in VERY hot weather. Model Ts do not like thick oil. Ford recommended a quality oil with a low pour point. (cold test) That roughly corresponds with 20W. A good 10W30 conventional or synthetic is a good choice for general use. In cold weather areas, a 5W20 or 0W20 is fine. I have run 0W20 full synthetic in 105F weather with no issues. Detergent oil will not harm a Model T, and is likely to benefit it.

Use oil and only oil. 10W-30 is my preference. Got off the 30W non D years ago during a cold snap when it wouldn’t start

10W30 Mobil 1 High Mileage synthetic

After you get the 30 or so usual replies, which will run the gamut of all possible viscosities and chemistry, you'll realize that just about any motor oil will do**. The most important thing is to be sure you have enough of it. Check your oil frequently. I check mine every time I buy gas.

** Once you've picked your favorite, you too can chime in when the next guy asks. Then you'll know you're a real Model T guy Have fun!

I use 10W30 Valvoline from Walmart. It should be changed at least every 1000 miles or once a year. Since a T has no filter and can pick up particles from engine wear and some carbon from blowby and band litter, I like to use the screen at the top of the hogs head with the magnet inside.
Synthetic oil is a waste of money because it is made for modern cars with full flow filters and long periods between oil changes. We must change more frequently on a T. so regular detergent oil is fine.
Norm

Detergent oil in a recently rebuilt engine.
Non detergent oil in an engine with unknown maintenance history.

Art Mirtes

Norman - With all due respect, I'm not sure what the price difference between conventional and synthetic motor oil is in California, but here in NY the price of synthetic is now lower than conventional. A five quart jug of Valvoline 10W-30 conventional motor oil costs $36.49 (plus tax) on the Walmart website. The same size and viscosity jug of Valvoline full synthetic costs $26.96.

I used synthetic oil and this happened!!

Can you blame that type of damage on a certain type of oil?

10W30 sounds reasonable to me for most applications but whats the verdict for adding ZDDP? I had a camshaft erode on a classic Mercedes I have and was told by the Mercedes Classic Center they felt it was because I used a modern synthetic oil which does not have ZDDP. I put in a new camshaft and have ever since used conventional oil and added ZDDP and have had no more issues.

SteveK wrote: ↑

Tue Oct 31, 2023 12:00 am

10W30 sounds reasonable to me for most applications but whats the verdict for adding ZDDP? I had a camshaft erode on a classic Mercedes I have and was told by the Mercedes Classic Center they felt it was because I used a modern synthetic oil which does not have ZDDP. I put in a new camshaft and have ever since used conventional oil and added ZDDP and have had no more issues.

How are you able to add ZDDP?

Dan McEachern wrote: ↑

Mon Oct 30, 2023 11:26 pm

I used synthetic oil and this happened!!

IMG_5623.JPG

Per Royce's recommendation, I run Pennzoil 5W30 high mileage year round for the most part. Seems to work fine, although so do all the other oils that folks run.

I also keep one front wheel chocked and the brake lever fully forward (high gear) when the car is parked in the garage. This keeps the high clutch compressed to minimize the oil sitting between the clutch disks. Of course, I remove the rear chock and pull the brake lever fully back before I start the car!

SteveK wrote: ↑

Tue Oct 31, 2023 12:00 am

10W30 sounds reasonable to me for most applications but whats the verdict for adding ZDDP? I had a camshaft erode on a classic Mercedes I have and was told by the Mercedes Classic Center they felt it was because I used a modern synthetic oil which does not have ZDDP. I put in a new camshaft and have ever since used conventional oil and added ZDDP and have had no more issues.

I didnt want to get involved here, but since you brought it up.
I run valvoline 30 wt racing. It contains ZDDP.

Lighter oil if you run when it's cold or have a stock motor. If you keep your t in a heated garage and run during nice days it doesn't matter. Running in triple digits all day heavier oil. Synthetic will maintain it's viscosity better than conventional when it gets hot.
I typically run 10-40 or 15-40 in my cars but I've been running in south FL summer heat. Now that I'm in TN and dealing with more pleasant weather I will be adapting to 10-30. On the 29 Buick as it would be my go to in winter possibly 5-30.

FYI full synthetic 10-40 is near impossible to find anywhere other than advance.

I buy ZDDP in small bottles from Amazon. Not cheap but it does work. But never use it in cars with catalytic converters as it will destroy them.

FWIW, ZDDP and related compounds were "discovered" in the 1940s, according to Wikipedia (gasp!).

https://en.wikipedia.org/wiki/Zinc_dithiophosphate

Model Ts do not need ZDDP. Modern oil, synthetic or "conventional", will do a very good job in a T engine, and a far better job than the best oil available in the 1920s. Multi-grade detergent oils are an excellent choice for the Model T engine. In this area. WalMart has nearly phased out conventional motor oil, and when they do have any, it's priced very close to comparable synthetic. Non-detergent oil is just about gone. You don't need non-detergent oil anyway. Some of it is of VERY low quality. If your engine is loaded with sludge, detergent oil is unlikely to cause a problem, and it can be expected to help slowly remove existing deposits and prevent future deposits. If your engine is very filthy, you need to remove the pan cover and clean out the worst of the deposits, then run detergent oil and change it if it becomes heavily contaminated. An engine that is full of sludge probably also has a lot of band lint in it. Running such an engine with ANY type of oil risks loosening old deposits and clogging the oil pipe and other vital oil passages. Clean it out.

For fans of ZDDP, I found this... https://static.speedwaymotors.com/image ... -Chart.pdf

I agree that Model T engines do not need ZDDP. I don't need to brush my teeth either, but I do to make them last longer than they would otherwise. It could be argued that even high pressure flat tappet engines do not need ZDDP either, but they wouldn't last too long without it. It seems to me that anything that mitigates friction at the tappet would be good for the engine, necessary or not. I make an oil filter system for my T's and posted several times in the past only to be instructed that "Model T engines don't need an oil filter". I incurred considerable scorn for the mention that it might be a good idea to filter the gunk out of the oil since the T engine didn't require it. Poppycock. Now I make the system for my cars and don't attempt to win converts otherwise. FWIW, I use 15/40 diesel oil which is inexpensive, widely available, matches the requirement of the engine, and still has a measure of ZDDP in it, whether it needs it or not.

ZDDP has advantages and disadvantages. It's not needed in a T, thus no advantage accrues from using it in one. I'd avoid high ZDDP oil in a T. Save it for your '69 GTX with a radical cam.

All engines need an oil filter. Model Ts lack an oil pump, which complicates oil filtration. The transmission cover screen/magnet devices are a good investment. A Texas T type auxiliary oiler might support a spin-on type filter. They can move a LOT of oil. Too much, in fact, for most applications. A Texas T oiler and 5W30 synthetic would probably put a fairly good flow of hot oil through something like a clean Motorcraft FL1 spin on filter. I would NOT remove the stock oil pipe with such an arrangement, since the pressure would not be sufficient to overcome a dirty element or to open the filter bypass as would be the case with an oil pump.

ZDDP has not been certified for use as a dentifrice.

TXGOAT2 wrote: ↑

Tue Oct 31, 2023 11:37 am

ZDDP has not been certified for use as a dentifrice.

Of course not. That's what Marvel Mystery Oil is for!

TXGOAT2 wrote: ↑

Tue Oct 31, 2023 11:26 am

ZDDP has advantages and disadvantages. It's not needed in a T, thus no advantage accrues from using it in one. I'd avoid high ZDDP oil in a T. Save it for your '69 GTX with a radical cam.

What are the disadvantages??

I expect my GTX needs it less than my T due to its better design & not relying on an inconsistent splash system.

Its my understanding, lubricative metals(ZDDP's) are removed, refined out & not added because of the possibility of clogging catalytic converters.
I dont run a catalytic converter on my T so......
Anyway, the oil I use is more in line with the motors design.
It may not matter, but Ill buy the cheap insurance with oil I cant get really, really cheap @ Wall Mart.
Thats my thinking. I dont preach either way.

Mopar 440 (and other big and small block V8s of the period) still rely on splash to lubricate the cam lobes.

I used to own a 1971 Plymouth GTX:

There are technical articles on ZDDP online.

ZDDP can be useful in high performance engines with high pressure valve springs, large valves, and aggressive cam profiles on non-roller camshafts It's not needed in a T engine. Period. Model T engines need a high quality, light to medium viscosity oil with excellent cold flow characteristics. Modern multi-viscosity oils meet and exceed those requirements across a very wide range of operating conditions.

From https://modeltfordfix.com/care-and-feed ... el-t-ford/ --
Ford specified the oil grade as “Light”. But what does that mean exactly? How do we know what “Light” oil is when looking at the oil available in the auto part store or Wal Mart? The guys who collect oil cans know the answer, because there was a period of time in the 1930’s – 1940’s when oil cans were marked with both the old “Light, Medium or Heavy” designations and the current designations. Here is an example of a “Heavy” motor oil from a Sinclair can of about 1940: So we now know the answer. Here is a cross reference chart:
--
Light = SAE 20 Medium = SAE 30 Heavy = SAE 40
So we know definitively that Ford specified SAE 20 when your Model T was new. Back in those days there was no such thing as detergent oil, and multi – viscosity oil was also decades in the future. Let’s consider the advantages and disadvantages of each of these technology advances.

Detergent oil sounds like the oil has some sort of soap in it right? In the 1950’s detergent oil was being introduced to the motoring public and horror stories abounded, particularly among folks who did not know anything about motor oil. There was an old wives tale that if you used detergent motor oil in a old engine that somehow all the oil residue, dirt and sludge that had accumulated would come loose and destroy the engine.

Of course it wasn’t true. Detergent oil suspends impurities in the oil. These impurities are too small to be captured by oil filters, and consist of such things as soot, combustion chamber by products, and dirt. These things combine to turn the oil dark over time. This is a good thing that you want to happen. When you drain detergent oil all those non – oil compounds drain out with the oil.

Oil viscosity is determined by the rate an oil can be poured through an industry standard orifice at industry specified temperatures. An oil that meets these standards for SAE 30W is branded as such. An oil that meets the standard for SAE 5W is branded as such. The “W” stands for “Winter”. Obviously a lower number flows better in winter test conditions than an oil with a higher number.

Multi Viscosity oils were developed to help reduce engine wear. Most engine wear happens when oil is cold and thick. The oil takes longer to reach wear surfaces when it is too thick to flow properly. This is a particularly serious problem for the Model T because unlike modern cars a Model T does not have an oil pump. So we do not want oil that is too thick to flow.

How does multi viscosity oil work? It sounds like the oil transforms itself when it gets warm doesn’t it? Again, this is a false statement generated by folks who don’t understand oil. Multi viscosity oil essentially stays the same when it gets warm. It does not get thinner like a straight weight oil would. This is a good thing for your Model T.

How about “Zinc” in motor oil? It was greatly reduced in most motor oils around 2007. Does this mean my Model T is going to seize up or suffer some horrible engine damage?

No it doesn’t. ZDDP was first specified as an automotive additive for the 1955 model year. The reason was that new 1955 cars with ultra high performance engines were using stiffer valve springs to enable higher RPM which yielded higher horsepower. These cars used “flat tappet” lifters along with overhead valves. AS RPM increases, the amount of inertia generated by the camshaft parts requires stronger springs to close the valve and to keep the lifter from hopping up and down on the camshaft. The increased friction from the super strong valve springs in these 1950’s cars caused rapid wear of the camshaft and lifters. This had never been a problem in older engines, and it was never a problem in the Model T Ford.

Bottom line – do you need high ZDDP motor oil for your Model T? No.

With all this being considered, what oil is best for the Model T? Let’s consider one more thing – operating temperature where you live. If you live in a hot, desert environment such as Saudia Arabia where cool morning temperatures are 85 – 90 degrees F and afternoon temperature reaches 120 degrees F you will want to use something like 10W-40.

In areas with average temperature between 40 and 110 degrees F you will want to use 5W-30.

Operating a Model T in winter weather, with temperatures between 0 and 40 degrees F you will want to use 0W-20.
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My 2 cents
Stock Model T engines have no oil pimp nor a filter. Lubrication is dependent upon splashing oil. Also the transmission is lubricated by the same oil and that is termed as a wet clutch. There are automotive oils formulated for wet clutch systems, like some diesel and motorcycle engines.
Th oil specification for these references JASO MA. These oils deliver the needed friction performance to prevent the clutch from slipping and are therefore non-friction modified. Many T owner's recommend ROTElLA T4 which has that specification. All things considered then perhaps this may be the most suitable ROTElLA T4 10W-30

If someone mentions water pumps and fuses in this thread, I get bingo.

The T4 oil might improve transmission and brake band performance. The T clutch is metal-on-metal, and designed to operate with plain motor oil, so I doubt it would either help or hurt it. Mutil-grade oil is the best thing for Model Ts and similar engines.

Arbs wrote: ↑

Tue Oct 31, 2023 3:05 pm

If someone mentions water pumps and fuses in this thread, I get bingo.

. . .so about 12v starters . . .

I was wondering if I can use an electric power steering pump as an oil pressure feed, run a water pump drive off it, and when I do, if a 20 amp fuse would protect it? I am using a 9 diode rectifier to convert my magneto to DC, that will work, won't it? After all, it's painted black, and I'm sure Henry would approve...

( --BINGO-- )

I don't see any need for a pressure oil feed with a standard crank and rods. The whole T system is splash system and as long as oil is getting into the dips in the crankcase under the engine it will work. A pressurized system works with drilled crankshaft but it would take major modifications to a T engine to achieve it. Even a Model A uses the same system. The oil pump on an A only raises the oil to fill the dips in the pan under it.
Norm

I skimmed the prior responses so forgive me if I restate something already mentioned.

I use Shell Rotella 15W40 non-synthetic, detergent oil. In a new engine detergent oil is fine and will help to keep it clean. If an engine is worn and has never had detergent oil then you should probably stick with non-detergent. The Rotella bottle will say "for diesel engines" but don't let that bother you. Rotella contains ZDDP and for me is the oil of choice in all my older engines. True, the Model T doesn't benefit that much from it but it doesn't hurt either. I buy it in gallon jugs which is great for doing an oil change and it provides me with a jug for the waste oil.

The normal operating range for my open touring is 40-100° F and it has worked fine for me.