Synthetic oil

W

wrndln

Well-known member
Maybe this topic has been covered before, but I haven't seen anything about it. I am wondering if synthetic oil would be a good lubricant for a newly rebuilt model A engine. The engine has babbitt bearings. It costs quite a bit more, but it seems like it would protect better and last longer than regular oil. Will synthetic oil last longer between oil changes? Has anyone been using synthetic oil and if so, what were the results?
Thanks for in input on this.
 
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Good questions. Synthetics really show their worth under more severe conditions than typically found in a Model A engine. There's certainly nothing wrong with using a synthetic in our old engines - it's just not necessary. No matter what oil you choose, the antioxidant, corrosion inhibitor, antifoamant, detergent, dispersant and other additives will get used up just like a Rollaids gets used up in your stomach after it does its work, so you really can't extend the oil change interval with a synthetic. I'm sure those using synthetics get the same performance as those of us who use mineral-based oils. It's your money and your choice - have fun!
 
I've used synthetics in modern cars and like them but with our fairly broad tolerances in the A the slippery synthetics might slide right through.
 
The oil debate is long and with many opinions. However, in the absence of an oil filter and an air cleaner, the interval between changes shouldn't be extended regardless of type of oil used.
 
I have used synthetic oil in the past on both older engines and a newly rebuilt one. I used Mobil 1 15W50 and had good success. The engines run very clean and seem to start easier than with conventional oil due to the lower viscosity at lower temperatures I guess. The use of synthethics is well documented and compelling.
I also have a full fow filter, but tend to agree with the above posts that perhaps the use of synthetic oils is overkill.

I have gone back to Castrol 15W40 diesel oil.

One down side of synthetic oil is that my car leaked significantly more with the synthetic than with conventional oil from the rear main. I understand that the capillary action of synthetic oil is more pronounced than with conventional oil, which is desirable for lubrication, but no so good for our leak prone "A"'s.

Dick
 
My understanding is you should not use synthetic oil until the engine is broken in since it prevents the "wear" necessary for breaking in.

After "the break-in-period," however long that is, synthetic oil has to be better, evan than Rotella.
 
Bruce has it right - don't put synthetic in a new engine until you are sure it is broken in. It never will properly seat if you start with such good oil.
 
The most important time to use the oil additive ZDDP is when an engine is new. I would recommend using the Valvoline VR1 "racing" oil that is available at Autozone. It comes in straight weight 30W or you can get it in multi-weight and it has ZDDP in it. The other oils have had it removed due to EPA regulations and engineers saying that it was no longer necessary in newer cars. Many classic car owners were unhappy about it.

I would really recommend using an oil with that ZDDP (Zinc Phosphorous) additive since our engines are flat tappet engines. People have seen premature cam and tappet wear in new builds and have attributed it to the absence of the ZDDP additive.
 
Bruce;

You are correct. It is recommended that the first few hundred miles be done on conventional oil. On my rebuilt engine I did the first 500 on conventional and then switched to synthetic.

Dick
 
I've always heard dinosaur oil at first and then synthetic later. However, I just read this on the Mobil 1 website and thought I would bring it up for discussion:

Myth:
You should break in your engine with conventional oil, then switch to a synthetic oil like Mobil 1.

Reality:
You can start using Mobil 1 in new vehicles at any time, even in brand new vehicles. In fact, Mobil 1 is original equipment (it is installed at the factory) in:
  • Acura RDX
  • Aston Martin
  • All Bentley Vehicles
  • All Cadillac Vehicles
  • Chevrolet Corvette C6 and Z06
  • Chevrolet TrailBlazer SS
  • Chrysler 300C SRT-8
  • Cobalt SS S/C Coupe
  • Dodge Caliber SRT-4, Charger SRT-8, and Magnum SRT-8
  • Jeep Cherokee SRT-8
  • Mercedes-Benz AMG Vehicles
  • Mercedes SLR
  • Mitsubishi Evolution
  • Pontiac Solstice GXP
  • All Porsche Vehicles
  • Saturn Ion Red Line and Saturn Sky Red Line
  • Viper SRT-10
One of the myths surrounding synthetic oils is that new engines require a break-in period with conventional oil. The fact is, current engine manufacturing technology does not require this break-in period. As indicated by the decisions of the engineers who design the high-performance cars listed above, Mobil 1 can be used starting the day you drive the car off the showroom floor.
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"One of the myths surrounding synthetic oils is that new engines require a break-in period with conventional oil. The fact is, current engine manufacturing technology does not require this break-in period. As indicated by the decisions of the engineers who design the high-performance cars listed above, Mobil 1 can be used starting the day you drive the car off the showroom floor. Watch our answer to this myth."

I somehow don't think that was written in the 1930s. :D
 
Synthetic oil will work and be ok in a Model A engine. Using synthetic oil in a modern new engine is ok, but in a Model A engine; that is questionable concerning break-in, and I would use conventional oil for break-in.

Back in the 70's (I think); there was an article in "The Restorer" about an around the world trip by four Model A's. One of the vehicles was a panel type, and carried most of the spare parts; so it was weighted more than the other three. The driver used Mobil-1 the entire trip; over 14,000-miles if I remember correctly. He also checked main and connecting rod clearances before and after, and found the wear to be negligible.

I wouldn't be afraid to use synthetic.
 
i run Mobil 1 full synthetic 15/50 with no trouble or leaks. it has about the same zinc content as rotella 15/40 according to the Mobil 1 web site. i still change it regularly as i would a conventional oil. i have used it since my motor was rebuilt and i run no oil filter
 
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I see nothing wrong with running synthetic oil, but from an economic standpoint, I will only use regular 10W-30 detergent oil in my "A". I change my oil every autumn, so it makes no sense to me, economically, to use synthetic.
I do use synthetic in my modern cars though.
Rog
 
I have used Mobil 1 synthetics in my modern car, push mower, edger and my Model A’s. There is substantial documentation of the superior performance of Synthetics and particularly Mobil 1 Synthetics. I have been using synthetics for over ten years.

I first used Mobil 1 15W50 synthetic in my 29 Tudor in 2005 after the bottom end was tighten up for the last time and I wanted to insure the motor lasted as long as possible. The results were the motor significantly quieted down and with a full flow oil filter and air filter the cost of the 4 ½ quarts well worth the $26 at Wal-Mart.

I also changed my 29 pickup over in 2006 with full flow oil filter and air filter.

Before changing to synthetics I cleaned the valve chambers and the oil pan on both A’s. After about 3 hours of use I cut the first oil filters open on each of the A’s and was amazed at the dirt particulates I found. I became a believer in the value of oil filters on model A’s. With the oil filters you can extend the interval on oil changes. If you learn to adjust the choke control valve to about ¼ turn open the gas contamination will be minimized and oil change can be extended. See www.model-A.org for procedures to adjust your carburetor and timing.

Since the middle 1990’s Mercedes come from the factory with Mobil 1 and 10,000 mile oil changes and they provide no charge oil changes for 50,000 miles. Mercedes filters are large capacity and smaller micron filtration than any vehicle I am familiar.

Mobil 1 also has motor oil for extended service of up to 15,000 miles. Synthetics are engineer for racing and they have different formulations for different conditions and length races. By using lower viscosity formulations teams can pick up 10+ or more horsepower. Joe Gibbs owns his own synthetics oil company.

Another point for the argument of whether to use an air filter is to look in your Model A judging standards in area 16 you will see the air filter is an acceptable Ford approved accessory.

There is no wrong decision on using synthetics. It is a choice based on your analysis of motor life versus synthetic cost.
 
I like the idea a of using synthetics in the A and moderns because of their apparent increased lubrication ability, but I have never been able to get a straight answer to Olds 182's comment about detereation (sp) of the additives and if they last longer in the synthetics.Logically I do not see why they would. But I dont know. Like Olds, I dont see any point in the increased cost if the additives dont last any longer than in regular oil. Does anyone have any facts on this? Would really like to know.
 
PC/SR said:
I like the idea a of using synthetics in the A and moderns because of their apparent increased lubrication ability, but I have never been able to get a straight answer to Olds 182's comment about detereation (sp) of the additives and if they last longer in the synthetics.Logically I do not see why they would. But I dont know. Like Olds, I dont see any point in the increased cost if the additives dont last any longer than in regular oil. Does anyone have any facts on this? Would really like to know.
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Maybe its just me, but it's not the additive longevity I would be paying for, but the superior lube properties that permit synthetic oil to remain in use longer than mineral oil.
I use synthetics in my modern cars and plan to use synthetic oil in my new A engine following it's break-in period.
 
A friend had a motorcycle engine repair business, only Harleys(shovel and panheads). Last year he had to go out of business and only does a few engine rebuilds on the side now for friends. He told me one of the reasons he lost business was the use of synthetic oil, he had engines that would have worn rings and valves(due to lean runs mostley) but the roller and plain sleeve main and cam bearings had no wear to speak of, years ago the Harleys would wear the bearings as fast as the rings and valves. I am an airplane A&P and synthetic oil is used throught out the industery, the companies wouldn't go to the expense if it didn't reduce wear.
 
Great discussion! As stated earlier, whether using a synthetic or mineral based oil, the additive packages included in the oil (about 25%-30% of the quart) get used up over time, and it depends significantly on the conditions under which the engine is operated. The additives in synthetics are chemically similar to those used in mineral oils, particularly in "branded" API-certified oils, but all are designed to perform their required function and eventually will be depleted. That being said, there are essentially 3 advantages synthetics have over mineral oils: 1. They are more thermally stable because of their synthesized same-size molecular structure. This translates to better high temperature properties leading to lower thermal and oxidative degradation than mineral oils under high engine temp conditions. Since lubricant decomposition and oxidation are precursors to thickening, varnish and eventually sludge, this is important regarding engine cleanliness. 2. Synthetics flow better at low temperatures than mineral oils, again because of their structured molecules. This is an advantage in very cold regions for easy starting and quick oil circulation. 3. Synthetics have low volatility and can directly affect oil consumption. To apply the above to our Model A engines we might consider the following: We tend to run our engines at relatively low crankcase temperatures, most of us don't bother to run our Model As when the ambient temperatures are below zero, and with a 500 mile oil change interval, oil volatility is a non-issue. There's no question that synthetics are superior oils, but considering the oils that were originally available to Henry when he was building these engines, any good (additized) mineral based oil will more than adequately do the job of keeping our engines clean, lubricated and cool. The choice really is personal.
 
Old182 said:
3. Synthetics have low volatility and can directly affect oil consumption.
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Does this suggest they increase or decrease oil consumption?


BTW, this is exactly the kind of thread I wish could be stickied in the forum. It would stop or at least decrease the amount of duplicate threads created and would be a great instant resource for people new to the forum.
 
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