VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 Engine Oil Choice

We have a member in our club with a 33 sedan that needs an oil change. This car was cosmetically restored a while ago but she does not think anything was done to the engine. She cannot recall ever having the oil changed since owning it. The engine runs fine with no lifter or bearing rap but the oil must be very old. I know when I did the motor in my 32 I used 10W-30 detergent along with a splash of ZDDP in the new engine but have no idea if the engine has detergent or non detergent engine in it now. My thought is 10-30 but like to hear what you all think

So here is the question:
A. SAE 10W-30 detergent
B. SAE 30 detergent
C. SAE30 non-detergent
D. Get a Beer and think about it

Thanks for any and all input.

10W-30 detergent.

That's one for A

10w30 Detergent.

Unless you're here right now where it's -40 tonight. The daily drivers have 0w20 synthetic in them and it still hurts me to start them in this weather. (My 38 Canadian owners manual tells me I should be using SAE10 with 20% kerosene in this weather lol! Those were the days)

10W-30 That's 3! Been using it for many, many years in 1928 & 1931 Chevys.

I also vote for 1-30W detergent oil. My experience is with two 1928 engines.

One, in Lurch (see link below), was VERY worn (at least for the last 35+ years I can verify) and it ran fine on 10-30W. It did not burn any oil, although the compression was very low. Two years ago I rebuilt the motor (bore the block out, new pistons and rings, and had the head rebuilt) and it has been running on 10-30W ever since. Because of the engine refresh, for the first couple of oil changes, I added Lucas Oil TB Zinc Plus Engine Break-In Oil Additive, based on a recommendation from the local machine shop that did the boring and head work. This might only be applicable in California, where the zinc has been phased out of the oil supply because it messes up the state-regulated smog systems. The additive was for brake-in purposes only.

The other engine, in Justin (see below), was sort of rebuilt in 1970ish, but never fired up until December 2012. This engine also runs great on 10-30W.

Cheers, Dean

I go with the A and D. A is good for your Chev and D is good for you.
Tony

The great oil discussion; never-ending on all antique car forums.....
I have always used the cheapest 30W I can find, knowing it is 10x better than anything made in the 1930s.
Lately I've been getting it in 5-qt jugs at TSC.
Detergent if you know for certain the pan is clean, non-detergent for unknown engine condition.

j.m.h.o.

Chris,
Just so you and others are aware, the early Chevrolet engines rely on an oil mist created by the dipper passing through a pool of oil to lubricate cylinder walls, wrist pins and in some cases the rod bearings. If the oil is too viscous (thick) the process produces larger droplets that do not circulate as well as a mist of teensy particles. If you check the "factory" recommendations for those years, 20 weight oil is specified for the normal temperature range. Above 90 deg. F 30 weight is recommended, at very low temperatures 10 weight thinned with kerosene. 10W-30 covers most of the temperature range.

Also be aware that a common problem with early Chevrolet engines was piston pin/bushing wear. High viscosity oils are a contributing factor.

I vote for 10-30, I think it would be prudent to maybe drop the pan for a look at conditions as well as sludge.Otherwise take a good look at the oil that has been drained to note condition of the old oil. Does this car have an oil filter?

J-Franklin brought up a good point about dropping the pan for an inspection. As Chipper mentioned, these engines rely on splashing oil around to get everything lubricated and if any sludge is plugging up any holes, that's a real problem.

With the oil pan off, you can scrape out any sludge in the pan, but also look at the oil reservoirs that feed oil into the cam and main bearings. You need a little mirror and a flashlight to inspect the reservoirs. I used Qtips that were wet with WD40 to clean out my reservoirs.

It is also a good time to make sure everything is as tight as it should be.

Cheers, Dean

The sludge issue was a bit on my mind because i remember people saying if you went from non detergent to detergent oil you will loosen up all the sludge in the bottom of the pan. I have a feeling this engine was rebuilt at some point and was probably filled with modern detergent oil. Just to frefresh my memory...5 quarts for an oil fill on the 6 ?

Loosening sludge or deposits when changing from non-detergent to detergent oil has been done millions of times and is not the problem that some will tell you. They are using the logic that detergents will remove grease and dirt from your hands and clothes so it will also do the same in the crankcase. Well let me in on a little secret. The detergents to make oil loving stuff suspend in water are vastly different that those in engine oil. And for the most part there is only one phase "oil" present. Okay, no more chemistry lesson today (unless you insist).

How much is a splash of ZDDP?

Contrary to some others who go with the cheapest oil they can find, I have been using Valvoline 10W30 VR1 Synthetic Racing Oil in my 1933 Master. It has higher levers of both Zinc and Phosphorus for older engines like some of the other brand racing and classic car oils have.

When I bought the car in 1971, I removed the pan and cleaned out all the gunk while adjusting the connecting rod bearing. There was 3/4 of an inch of tar like junk in the bottom of the pan. Have not had any issues for the past 48 years.

A 1933 engine does not need zinc. The lifter to cam lobe load is very slight on the old engines. They did not add zinc to oil until the 1960's and the old straight 6 cylinder engines never wore out a cam lobe.

Vila
And others,

The use of synthetic oil in an engine with any sludge or gunk is risky. The sludge and gunk was insoluble enough to drop out of suspension or solution. I will not go into detail about the chemistry of the synthetic base oil as it probably would not be understood by all but a few that read this. One property that should be considered is there is definitely a difference in the surface activity between mineral oil and synthetic oil. That means some of the sludge and gunk could be more likely redissolved or suspended than if mineral oil base lubricants are retained. I personally will not use synthetic base oils in my old Chevrolets unless forced to by unavailability.

10w-30.

Regular oil with no additives that don't come with the oil.

No need for synthetic or a blend. A waste of money.

Also, get the cheapest brand. Wal-Mart brand or other parts store brands will serve just fine.

Best,

Charlie

All oil that has the SAE label comply with the specifications. That includes the lowest price as well as the most expensive. The difference in price has more to do with advertising cost than performance.

I have two 1936s. A Town Sedan and a 1/2 Ton Commercial Truck. Both have 30 SAE (Standard American Engineering) Non-detergent Oil in them. Both get a wash out by running the engine at idle for the recommend time with a factory recommended mix of oil and kerosene every 500 miles. I have had no problem due to my location in Northern Mississippi with running 30 SAE oil year round. Even in below freezing temperatures, snow and ice [ It does take more cranking power to start. I just let it warm up more.] After purchase of these vehicles [one in 1964 and the other in 2009] I pulled the engines down and cleaned out everything. In spite of this, the first few times I did get a lot of gunk out when the "wash out oil/kerosene" was removed. I have not had any problems with things "plugging up". The "wash out oil/kerosene" keeps the insides very clean as I have removed the pans and inspected last year. [2017] I think the mane thing is to keep oil level full.

Chipper,
thanks for pushing me up a little further on the Chevrolet learning curve.
I will switch to 10-30 on the next oil change, still shopping for the best price of course.
just cleaned out the pan last year, so detergent oil will work......

Where di you find Chevrolet recommending using keresene to flush an engine? I went through the shop and owners manuals from 1934 and up and saw no such infromation. In the 1950 owners manual it says not to used flushing oils but rather drain oil and add 3 quarts of #10 oil and run engine until oil is hot.

SAE stands for Society of Automobile Engineers

Gene,
The recommendation to use Kerosene is in earlier manuals. I believe it may have been recommended as motor oils had little to no additives and degraded fairly rapidly due to heat/oxygen and shear. It is a procedure that can lead to more problems than it might cure. Bearing wear due to lower viscosity and circulating abrasive or clogging particles are not a good idea. Better to leave that gunk resting on the bottom of the oil pan.

That is correct. These old engines with small valves don't have any where near the pressure load on the cam that high lift cams pushing 2.3" diamter, heavy valves with springs strong enough to close those valves at 7000 RPM as used on 1960s muscle cars do.

Doug

Chipper's advice is right on.

It is in sync with mine. Oh, my, Toto, we're not in Kansas anymore.

I agree with Gene's question about flushing with kerosene every 500 miles. Seems that would be a bit more trouble than necessary with todays oils. Just as Gene has advised many times they are much better than back in the day products were.

Just go to your local parts store or WM and get the store brand. If you check the information in the circle on the back you will get and education on the stuff in the oil by the letters displayed there. Gene and others have mentioned this many times as well.

Again, Chipper and Gene are right on. Yet, again, they smell an opportunity to give sound advice and are on the hunt as the best pair of bloodhounds would be. Take their advice seriously .

Best,

Charlie