What Oil should I put in my vintage 1935 Buick?

[pint4]

I have a 1935 Buick with 30,000 miles.  Are there oils formulated for vintage cars like mine?  Can I use synthetic oil?  What weight oil, straight or multi-viscosity?

Thanks!

Edited June 12, 2015 by pint4 (see edit history)

[Rusty_OToole]

There is a company called Penrite that makes oil for vintage cars, there may be other brands. I would take off the oil pan and valve cover and clean out any sludge then use 15W40 multigrade detergent oil like Shell Rotella or other good name brand oil. Do you have an oil filter? If not, it would be a good idea to install one.

[Vila]

This topic has been discussed numerous time on the AACA and other forums.  The most important ingredient for older cars other then the oil itself is Zinc.  Most oil for modern cars has a lower level of zinc, as it has been found to kill catalytic converters.

 

Standard synthetic oil does not have a high zinc level.

 

Penrite and Brad Penn both make oil with the higher zinc level for older cars with no cat.  Hagerty also makes a classic car oil with high zinc levels.  

 

Most racing oil also has a high zinc content.  I switched to Valvoline Synthetic racing oil for all my (pre-catalytic converter) antique cars since it has a high zinc level.  http://www.valvoline.com/products/consumer-products/motor-oil/racing-motor-oil/8

 

If you are switching from a non detergent oil to one with detergents I would recommend removing the pan, valve cover, and pushrod cover (if it has one) and clean all the gunk out of the engine.  My 1933 Chevrolet had a lot of gunk in those areas when I bought it in 1971, and I have not had any problems with this car over the past 40+ years.

 

Since multi-grade or detergent oil was not available when cars in the 30s came out, they used a single grade non-detergent oil.  I now use mulit-grade where the second number is close to what the original oil specification was.  If it originally used 30 weight I use 10W30, etc.  Other then the improvements in engine materials, why do you think older engines only when 70,000 or so miles before needing an overhaul?  Non-detergent, single grade oil.    Using a single grade oil is very hard on an engine until it get up to operating temperature.

Edited June 14, 2015 by Vila (see edit history)

[Rusty_OToole]

Oil didn't have zinc before about 1950. It was added to protect the cams and lifters on the new high compression OHV V8s. When the pushrod type flat tappet cam went out, they stopped adding zinc.

 

It is there to protect flat tappets and cams, roller tappets, and OHC engines don't need it. Pre 1950 engines never had it. Whether you really need it if you don't have a 1949 - 1980s flat tappet, OHV engine is an open question.

[Larry Schramm]

IMO, any oil today is better than any oil that was available when the car was built.  That said, I use Shell Rotella for my vehicles.

[Sweet64rivi]

Brad Penn.   http://www.penngrade1.com/Zinc.aspx

[Spinneyhill]

Richard Widman contributes to these fora occasionally. He also sells oil in Bolivia. He has researched oils for his Corvair and written it up here:

 

http://www.widman.biz/Corvair/English/Links/Oil.html

 

That said, if you want Zinc, use a diesel oil. He tells you about it in the paper referred to above. My 7 year old Iseki diesel tractor has flat tappets. Don't go on here-say. Look up the MDSS on the oil where it will tell you how much zinc is in it.

[Ben Bruce aka First Born]

IMO, any oil today is better than any oil that was available when the car was built.  That said, I use Shell Rotella for my vehicles.

 

 I agree. If was me, I would probably stick with non detergent if this is what was used in it, UNTIL I removed the oil pan and cleaned it. Like Larry, I believe the CHEAPEST oil today is superior to the BEST of 1935.  Besides , you will probably only drive a thousand moles a year, instead of a thousand a month.

 

  Ben

[Guest Bob Call]

In my opinion a lot of the oil stuff you hear is not correct or necessary. Your 35 Buick originally was designed to use a straight 30W and maybe 20W in winter. You don't need zinc additive. The zinc is only needed for high performance engines with flat lifters and high valve spring pressures. Use a good 30W oil like a Chevron or Shell product that is rated for diesel engines which have all of the additives necessary to protect your engine. Let your engine warm up for a few minutes before driving to be sure the oil is starting to warm and circulating through out the engine. You should always, if at all possible, drive the car long enough to get the engine to full operating temperature in order to burn off any water condensation in the crankcase. You've got a lot of cast iron in that straight eight and it takes a while to heat up all of it.

[Spinneyhill]

Not 30W, 30 weight. 30W means 30 wt when cold. It will be poor at circulating and lubricating when you start up. In my 1930 Dodge 8 I am using a 10W-40: 10 wt when cold for maxiumu lubrication on start-up, 40 wt when hot for best lubrication when hot. See the curves in Widman's paper. I change it frequently. The oil pan was clean when I started using this oil. I have tried 20W-50 but it is too thick when cold.

 

I don't recall any science being presented that convinces me to use non-detergent oil.

Edited September 14, 2015 by Spinneyhill (see edit history)

[1937-44]

 I also use 30W non detergent oil in my 1937 Buick and change it frequently. Non detergent oil deposits the particles it picks up in the oil pan rather than carrying them through the engine continually as detergent oil is designed to do until it is filtered out. In my opinion if a car does not have a full flow oil filter, non detergent is the best oil to use.

 

 Science will probably never prove that non detergent is a better choice (if it is) as few people use it in this day and age and therefore there isn't enough money to be to do a study on obsolete engines.

[Spinneyhill]

Non-detergent oil deposits the crud anywhere it stops or slows, including the sump, around the valve gear, on top of the oil intake in the sump, bottom of the timing cover, against every surface in the sump and timing cover and valve chamber and elsewhere in the engine, on the connecting rods when they stop and so on.

 

It is SAE 30, NOT 30W. Can you buy 30W? 30W would be far too thick to lubricate the engine when it is not up to temperature and your bearings etc. will wear more quickly.

[1937-44]

  Spineyhill you are correct that non detergent oil deposits the crud everywhere, whereas detergent oil holds the crud in suspension and just keeps carrying the crud over the bearings and other surfaces until it is removed from the oil. It also has no oil filter so I prefer the crud to be deposited rather than continually recirculated. If my car had a full flow oil filter and had been rebuilt recently I would use a multi grade oil, however since neither is the case I stand by my decision to run 30 weight non detergent.

 

 You are also correct perhaps I should have referred to it as non detergent SAE 30 instead of 30W however the terms are somewhat interchangeable. If you look at O'Reilly's site (http://www.oreillyauto.com/site/c/search/Conventional+-+30W/N0436/C0162.oap) for instance they list SAE 30 as have a viscosity of 30 W.

Edited September 14, 2015 by 1937-44 (see edit history)

[Spinneyhill]

If you insist on using SAE 30, non-detergent oil, you had best make sure it is a good quality base oil. Otherwise you are promoting rapid wear in your engine. You want a Group II or II+ base oil. You might have to look up the MSDS for the oil to find out what it is. Remember that reputable oil companies make oil down to the price the customer (Walmart, for example) asks for so they could be using obsolete plant and left over low quality base oil to make such low grade oil.

 

How do you tell you have rapid engine wear? Early engine rebuild, blamed on anything else you can think of. You can find out by doing a metal test on the used oil when you drain it. Remember that a 30 grade oil is pretty thick at startup so if your engine has been siting for a week or three, it will have drained away and there might not be much protection for the tappets, timing gear, bearings etc. until the oil is pumped around and a 30 weight is pretty hard to pick up and pump when cold. You will want rapid warmup so you had best have an operating thermostat in the engine too.

 

Here is a quote from Widman's paper, p. 18 item 10.

Forget the myth that you can’t put high detergent oils in older engines or engines that
have been using poor quality oil. I do it every day! 50% of this market is API SF or
lower, frequently without thermostats. They are full of sludge. Some drain plugs come
out looking like a cork, with an inch or so of thick sludge on the end. No matter what
the engine, I put in a 10W-30 high detergent CI-4 oil and instruct the customer to come
back when it thickens up, or the following week if he doesn’t want to check it himself.
Once it no longer thickens up quickly we move on to 15W-40 and add a 1200 mile
engine cleaner. At the end of that cycle we move to whatever oil the engine should have.

 

Please read Widman's paper. Yes, it is hard going at times, but take your time and come back again and you will pick it up. I have read it several times and pick up something else every time.

 

Just note that with low detergent oil you are probably not scavenging the combustion products from the engine very well and you probably also have insufficient antioxidants to prevent corrosion from condensation.

Edited September 14, 2015 by Spinneyhill (see edit history)

[Spinneyhill]

Some more thoughts about "non" detergent oil.

 

Many of the particles in the dirty oil are very fine. When you stop the engine and the oil drains into the sump, it leaves some of the particles behind. This would include in the bearings, on the tappet tops and sides and in the timing gear. So on startup with SAE 30 weight non-detergent oil, there is dirt lubricating these surfaces for a while before the oil arrives. The oil will pick up a certain amount of the dirt by turbulence, but some will be left behind because there is not much detergent. The engine becomes clogged with fine dirt.

 

The detergent and dispersants in oil will help take the particles with the oil when it drains away. And if you also use a multigrade like 10W-30 or -40, you get oil to the wearing surfaces more quickly than starting with SAE 30.

 

I wonder what scratches bearings? Metal bits? They will settle out. I suspect the fines that are in suspension in a detergent oil are too fine to damage bearings. Anyway, the bearings should not wear if you have a strong oil film in there (there should be no metal-metal contact) and you don't lug the engine in high gear at low speed or rev it before it is warm and the oil is circulating fully.

Edited September 15, 2015 by Spinneyhill (see edit history)