MOTOR OIL ?

[broker-len]

have two old cars of the 30s 32 plymouth and 36----just had the motor in older one rebuilt it has poured bearings--the shop, which has been there sinse the 30s told me that multi grade oil is not good for the babit on these cars--suguest straight 30 weight but when I did I noticed that the oil presure was more constant in hot weather-----other friends have been using modern oil for years and no problem-------trying to get feed back from all you car guys----BR

[Rusty_OToole]

There are special oils made for the old cars. Penrite is a well known brand but there are others.

[Alfre]

I use shell rotella 15-40 since 1961 and no problems my cars range from 1923 - 1965 and there are 5 of them.

Al

[vermontboy]

I think most everyone uses what they are most comfortable with based on what they have read and been told. Most modern oils are known quantities in regards to additives - read up on it and decide what makes the most sense.

And remember that many of us back in the 60's were using one of the generic brands of "Pennsylvania" oil you could buy in 5 gallon pour spout cans at Western Auto or National Auto - when you were getting 100 miles to the quart you wanted cheap. They even sold "re-refined" oil back then - think about that for a minute.....

Detergent vs non-detergent, multi-grade vs single grade, and etc. They all have people that swear using anything else would cause their engines to blow up or wear out. It's more important to remember to change it often because it becomes contaminated much more quickly in old engines than in new ones - so change it every 1000 miles or so.

[Matt Harwood]

We recently hosted a technical seminar for our local CCCA club and this year had a pair of scientists from Brad Penn come to talk to us about old car oils. Now, granted, they make a special oil just for old cars, but their presentation was not about selling oil, it was extremely informative and heavy on science and history. They clearly knew about old cars and old engines and what hobbyists want in a motor oil. A few things I took away from their presentation:

One, Brad Penn (or Penrite) oil is the only 100% Pennsylvania crude oil. It's formerly Kendall, AKA "The green oil" that many old timers swear by. It is also the only oil currently on the market that is 100% made in America, from the ground to the shelf. That might mean something to some people.

Two, it's "sticky," meaning it clings to engine parts instead of draining back into the pan. That's why I use Mobil 1 in most of my cars, because it clings. But in my old cars, the synthetic oil finds its way through porous old gaskets and castings where regular oil won't. They did a demonstration of pouring some oil out of an unopened container of their oil, then dipping a metal rod in it, then spraying the rod with carb cleaner. The oil DID NOT want to come off. Very convincing.

Three, they pointed out that modern multi-grade oils like 10W30 weren't around until the 1950s, and unless you're running in cold weather, you don't really need the multi-weight. There's no harm in it, but they pointed out that with a multi-weight oil, you're getting additives that thin out the oil at lower temperatures, since they always start with a base stock of the thicker viscosity. Single-grade oils don't have these additives and have a more consistent flow rate once up to temperature. If you don't drive your car in the cold, you probably don't need multi-grade. No harm in it, but you don't need it.

Four, there's zinc in their oils. I won't get into the zinc debate here, but they addressed it saying that if you have a high-performance engine with a lot of valve spring pressure and flat tappets, it's a good idea. Older cars with lighter springs and lower lift cams aren't as critical, but it can't hurt. However, there is such thing as TOO MUCH zinc as well, so don't just dump a bunch of additive in your crankcase thinking you're getting extra protection.

Five, they recommend changing your oil at the end of the season and storing your car with fresh oil in it. The contaiminants in your oil WILL eat the bearings if allowed to sit for an extended period of time. Always store your car with fresh oil in it. I'll admit to making this mistake, changing the oil in the springa nd storing it all winter with dirty oil in it, figuring that since it's sitting, it'll get contaminated with condensation, but he said that's incorrect. Get the dirty oil out ASAP.

Now, as I said, they were obviously there to promote Brad Penn oil, but the presentation was given by a scientist, not a salesman, and the science was pretty compelling. I'm a skeptic in most cases, but they answered every question posed to them with a good answer, and there was no indication that they were just there to sell oil. As a result of what they said, I am now running straight 50-weight Brad Penn oil in my 1929 Cadillac. I bought two cases, which should be good for three oil changes.

In regards to the original poster's question, I don't think you're doing any harm in running multi-grade oil in your rebuilt engine. Everything should be new and in good order and modern oils are not going to damage your bearings, regardless of viscosity. I personally tend towards slightly thicker oils on my old cars simply because the clearances are not as tight as a modern car and it helps keep oil pressure up. Between the clinging of the Brad Penn oil and the warmer temperatures at which I drive it, there's really not much danger of cold start up starvation, in my opinion. And remember that any oil today is worlds better than the best oil when your car was new, so as long as it's clean and your car maintains proper pressure, then there's probably no harm in running whatever you like.

Hope this helps!

[Rusty_OToole]

I always understood that multi grade oil was made by starting with thin base stock and adding additives to prevent thinning at high temps.

In other words 10W30 is made of 10W oil with long chain polymers (like STP) added to prevent it from thinning out.

[bhambulldog]

I've been using 30w in mine since 1970.

I add one pint STP (blue bottle) to get ZDDP (zinc)

[1937-44]

Matt that is a very informative post and I enjoyed reading it. Thanks.

I would like to add one comment to the poster which is strictly my opinion. After talking to many people over the years I run non-detergent oil in my older (1930's) cars for two reasons. The first being my engines have never been torn apart and I do not want to dislodge years worth of crud that has accumulated in nooks and crannys over the years. The second reason is it is my belief that detergent oils pick up contaminants and continue carrying them over the bearing surfaces as I do not have a full flow oil filter on either car to capture the contaminants, thus creating wear. So my decision would be based on engine condition and whether or not it has a full flow oil filter.

My newer car a 1954 has a full flow filter and I run 10W30 in it with a small bottle of cam lube (for the ZDDP) added at each oil change.

Carl

[MikeC5]

Right Carl. The non-detergent oils do not keep contaminants in suspension; they settle down to the sump as was intended for engines without full flow through filtering (or any filtering at all)...

[Guest Skyking]

One, Brad Penn (or Penrite) oil is the only 100% Pennsylvania crude oil. It's formerly Kendall, AKA "The green oil" that many old timers swear by. It is also the only oil currently on the market that is 100% made in America, from the ground to the shelf. That might mean something to some people.

Hope this helps!

Matt, I also enjoyed reading your post, very informative.

When my father bought his new 1955 Buick Century I was 10 years old. He used to take it to a local garage where they specialized in Buicks. They used Kendall oils and back then my father used to brag how good that oil was. I wasn't aware they still existed. That Buick was handed down to my younger brother in the seventies who beat on it continually and not as much as a valve cover ever removed.

[64Riv-King]

Matt, I also enjoyed reading your post, very informative.

When my father bought his new 1955 Buick Century I was 10 years old. He used to take it to a local garage where they specialized in Buicks. They used Kendall oils and back then my father used to brag how good that oil was. I wasn't aware they still existed. That Buick was handed down to my younger brother in the seventies who beat on it continually and not as much as a valve cover ever removed.

Here's the link. I love this stuff...http://www.penngrade1.com/Default.aspx

[Guest Skyking]

Thank you for the link!!