VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 engine oil for 4 cylinder engine

What are some of the recommended engine oils for the 4 cylinder Chevy? Is Rotella T Triple Protection (predecessor to Rotella T4) appropriate or inappropriate? I know that it is formulated for diesel engines, but Shell says that it may be used in gasoline engines. My concerns are whether it is too viscous for the oil system in the 4 cylinder engine, and whether some of the additives might be harmful for a gas engine.

Best to just use 10/30 oil. Your engine needs a mist and splash to be properly lubricated. 10/30 will do it.

For my 1928 4 door sedan I use Valvoline VR-1 20W-50 racing oil, high zinc/ phosphorous. ZDDP. It’s available as 10W-30 etc. Though a racing oil it is compatible with passenger vehicles and is good for push rods and flat tappets. I started with Rotella but dumped it after a couple hours because it doesn’t have the zinc that is essential for friction reduction and lubrication of a rebuilt engine like the 1928 4 cylinder. VR-1 provides that. The fellow who rebuilt mine has done hundreds of engines over more than 50 years.
.... Ted.

I just use 10-30 in all my old cars

I use Valvoline conventional 10/30 in all my vehicles. I do not add any of the snake oils that are
advertised on t.v. or on flyers . In a state like Michigan in ice cold winner I would more than likely
use 5/30. ( Just my opinion, ) Been doin this for 65 years with no oil related breakdowns.

I also use 10W- 30 in all of my old cars. I don't worry about the brand.

Ted this is not intended to be personally critical of you. It is an attempt to counteract the misconception that zinc is critical or maybe even useful in our old Chevrolet engines.

Ted I don't know where you are getting the impression that modern oils do not have zinc (phosphorus). The truth is that the levels of have been reduced from the 1200 to 1500 ppm range to less than 800 ppm phosphorus as the reply from Mobil below substantiates. Oils available when your '28 was built had zero added zinc or phosphorus.

From the Mobil website "https://mobiloil.com/en/faq/ask-our-auto-experts/questions-for-auto-experts/has-zinc-been-removed-from-motor-oils"

“I am having thrust bearing failure in a 4.6 modified performance engine. This is a street/strip engine. Many of my friends are having the same problem. I think it is the result of the removal of zinc from the oil. I was told by two separate racing engine builders that the EPA ordered the removal of the zinc from over-the-counter motor oil. I use Mobil 1â„¢ 5W-20. Is this true and do you think a zinc additive might help?”
Randy Lovejoy, Americas, Georgia

Answer

The active ingredient that you are talking about is phosphorus that is added through a component called ZDDP. For products that meet the ILSAC GF-5 specification, the phosphorus levels for the oil must be less than 800 ppm phosphorus. The ILSAC level for phosphorus has been reduced to protect the catalytic converter and other emission protection equipment. The engine manufacturers are confident that this level of phosphorus will protect both new and older engines. However, there are Mobil 1â„¢ synthetic oils that have a higher level of phosphorus (phos) and can be used in engines in racing or high-performance applications; ."

It is up to you if you feel better to pay extra for oil such as Valvoline VR-1 20W-50. I have been running 1931 Chevrolets for 50 years and '28 Chevrolets for over 20 years. I use 10W-30 and wouldn't attempt to destroy my engines with too high viscosity oils such as 20W-50. The cylinder walls, rings, wrist pins and to a lesser degree rod bearings are lubricated by an oil mist generated by the "dippers" passing through the oil in troughs. Too high viscosity produces larger oil particles that do NOT lubricate the critical parts as well as the smaller particle mist.

Zinc added to oil as a metalic dust does nothing unless the oil film is squeeze out and the surfaces get hot. Then in bonds to the hot area for temporary lubrication.

The pressures in engines from the 1920's is very little compared to high compression / high performance engines with flat tappets of the 1960's and later. You can compress a valve spring from an old 4 cylinder in your hand. Lower zinc content shouldn't be a big factor.
Steve

With Y'all...........!

20w50 is extremely thick and I would never use in a vintage splash engine. Modern oils are way better than oils were 100 years ago. Chipper is a Chemist with decades of owning this vintage of car, so heed to his guidance and don't be sucked in to marketing hype. Chev Nut also has decades of GM dealer experience during the splash engine era. Their recommendations also are in line with the GM specifications for the era.

Anything thicker than a 5w30 or 10w30 will not provide proper lubrication for a splash engine. You could always choose a synthetic 10w30 if you wish to have a premium oil, but it is not necessary as any brand 10w30 will be better than a 20w50.

I'm glad I posted about the oil I started using because I now have good information for how to proceed going forward.
This spring I'll change to the 10W-30 as all of your comments convince me that is the best choice.
I probably have less than 10 total hours running this engine, all of it during the summer when it warms up quickly.
And less than 2 hours on the 20W-50.
Thanks for all of your comments.
.... Ted