MTFCA Forum

I know this subject has came up quite a few times but, the ol gray cells don't work as good as they used to.
I'm getting close to getting my 26 coupe running after 50 years. A neighbor said I should use oil that has zinc in it, which I suspect that most oils used today don't have. He suggested going to a large truck service center. I kinda remember someone saying that some oil don't use because that it will mess up the mag. Anyway your thought on the oil with zinc and which oil not to use. Thanks

Zinc is really needed when you have very strong valve springs. A Model T has very mild springs, so a high concentration of Zinc isn't needed. Any oil you get today is better that what was available "in the day". My preference is a high detergent non-synthetic motorcycle oil. That type of oil is designed to run where the engine and transmission use the same oil and have wet clutches. Others will say any oil on the bargain counter is fine. Basically it is up to you to run what you want.

I have just come off a problem with oil in a newly built motor. I asked the owner not to use Mobil 1 as I read the friction is so low, the rings won’t seat. So he used Castrol GTX.
The rings did not seat.
In June we’ll pull the motor, knock the glaze if any, off the bore and use new rings. I prefer to use Diesel engine oil, available at Costco, which contains zinc and other “bad” stuff which T engines seem to prefer.

Rotella 30W works for me, JASO rated for motorcycles, non energy conserving.

Richard - Just to clear up one minor point, you said that you kind of remembered that someone said not to use oil with zinc in it as it would "mess up the mag". I think you have it confused with graphite. It's oil with graphite that will short out the magneto,....FWIW,.....harold

Several past discussion on this issue linked owner preferences to magneto engines, old vs recent rebuilds. Thought it would help to provide some basic information on the differences in oil terminology for those in need.
Non-detergent oil was used before oil filters became standard equipment. This type of oil would "stick" contaminants to the sidewalls and valleys of the engine to prevent dirty oil from damaging bearing surfaces. Engines that have been run on non-detergent oil for many years will have a thick "sludge" buildup. (depends on oil changes too)
Detergent motor oils include chemicals that aid in trapping particles in oil filters, dispersant additives that break down coagulating sludge in channels, rust preventers and alkaline to offset the acidic nature of oil in general as it begins to oxidize. Again detergent oil was designed to keep deposits in suspension so they could be trapped in an oil filter - no oil filer? change your oil often.
Diesel engine oil is very similar to gasoline engine oil. Both have base oils that are formulated with a variety of additives to change particular oil properties. The difference between the two depends on the amount of additives that are used. In addition, diesel engines absorb more carbon while gasoline engines tend to absorb more moisture and tar. Diesel engine oils contain a higher number of dispersants and more anti-wear additives.
Synthetic oil offers several advantages of conventional oil. It copes better with temperature changes and does a better job of effectively lubricating various components in the engine. It also provides more stability in cold temperatures and is more effective at cleaning out dust and debris from the engine.
Multi-viscosity oil is designed to for temperature differences of a cold (first number) vs hot engine (second number). A higher viscosity oil, such as 10w30, will flow slower at low temperatures compared to a lower viscosity oil like 5w30. ... A higher viscosity or thicker oil will seal better than a low viscosity oil. A thicker oil will also provide better lubrication of critical engine parts.
The RISK in changing from non-detergent to either detergent or synthetic oil has to do with seals, gaskets, and other components that aren’t as tight as with newer models. Because synthetic oil does a better job of cleaning out sludge, it could remove deposits that are acting as seals. This could result in leaks that cause the engine to burn oil and require you to monitor your oil levels. If you don't, you risk damaging the engine or other components. As someone mentioned previously, carbon in suspension can effect magneto magnets.
Reduce your risk and change you oil often - and maybe pull the inspection pan to see if you get slug.

The oil Ford recommended for Model T use was SAE 20. I mistakenly assumed that 5W-20 would be OK. It's not, and I suspect that may have been a contributing factor to my rod failure. This chart from the MTFCA engine book shows the various weights.



My oil page has a link to Royce's excellent article on oil: http://dauntlessgeezer.com/DG103.html

After a couple years of reading many, many opinions on oil I believe that the right oil for my T isn’t necessarily the right oil for yours. My own current strategy is to favour changing oil frequently instead of seeking fancy additives, and I’m homing in on the right viscosity for the climate I drive in and the age of my engine. At present I have an engine full of cheap 10W30 but I think I’ll bump it up to 10W40 after a good look at Steve’s chart above.

Because of the variation in use that our cars have seen and currently see, I think the best we can do is pick an oil for our own individual situation.

Most any oil avaliable today for gasoline engines is way better than any oil avaliable when Model T’s were new.
I think to much is made of for a ‘special exotic’ oil for T engines. There is no need to spend more money for synthetic, special blended, $8 dollar a quart exotic oil to start or run in your T for better this and that.
House brand oil at Auto-Zone, Wal-Mart such as 30w, 10w30 or a lighter grade for cold climates will work great.

Tiger is right on - there are several variables that should be considered in selecting "your" oil weight. When making a recommendation it may help others to know some things about your usage (climate, miles driven, problems, magneto yes/no, etc).
Since all oil degrades over time (its a chemically engineered product) the best thing you can do is to change it often. So inexpensive 30W (or 10W30) changed every spring time may be a better cost effective solution then using expensive synthetic oil and changing it every 1000 miles. For those so inclined to dig deeper into the subject, this link covers all the jargon, and contains more information than you may want to know https://en.wikipedia.org/wiki/Motor_oil#History

dunoon wrote: ↑

Mon May 27, 2019 3:19 pm

I know this subject has came up quite a few times but, the ol gray cells don't work as good as they used to.
I'm getting close to getting my 26 coupe running after 50 years. A neighbor said I should use oil that has zinc in it, which I suspect that most oils used today don't have. He suggested going to a large truck service center. I kinda remember someone saying that some oil don't use because that it will mess up the mag. Anyway your thought on the oil with zinc and which oil not to use. Thanks

You're probably getting the idea by now, everybody has their favorite choice. Just about any oil that's made for engine use and that does not have graphite, (which would be very hard to find even if you wanted graphite), will be just fine. What's more important, is to always have enough of it in your engine. Check your oil every time you buy gas. If it ain't coming out of the top petcock, add until it does. I never touch the lower one.