1977 DeVille, 425ci, which engine oil?

[Koa]

Hi Caddy Masters,
what can You recommend as the best engine oil for my 1977 beauty? On the dipstick I found "Use only SE oil".

[Big Fins]

What are you using in the Brougham? Temperature in the area of operation plays a factor in the weight used. Look in your owners manual, it will tell you the weight of the oil needed for your geographical location. Today's oils are backward compatible. But I would say 10W-30 is what is generally recommended. Choose the brand that you like best.

You are now going to get 50 differing answers, brands and weights.

[TJ Hopland]

I notice on his list of cars he has a Tatra which is a Czech brand so he is probably in Europe where there are completely different options than we have here in the USA.   Perhaps there are others from that general region that can recommend specific brands or types that may be commonly available there?

In general there isn't anything too special required for these cars.  What have you been running in the 78?  Same engine there so same stuff should work.   What oils are usually used in 40+ year old engines there?   In the USA some people are using diesel oils in these engines.  The thinking is that since most gas/petrol oils now are intended for modern engines that don't have the contamination issues older engines had.

I don't even know if oils are sold with ratings like 10w-30 there?   All I know about European oil is apparently the engine manufactures go by a spec number.   

[Koa]

Hi TJ,
You are right, I am in Europe, Czech Republic.
We also have specifications like 10w-30 .... . Fleetwood 78 is really almost the same car.
The question was rather, what would You put in Your car from this age? As "SE oil" is recommended, can I still buy this one ore can I use a new one without any risk of getting some trouble?
Several times I bought some parts from Rockauto. Maybe it sounds crazy for You to buy a bulb for 6 USD and than pay 25 USD for shipping, but there is no other choice, since we want to keep these wonderful cars running.
So, what kind of engine oil from Rockauto would You recommend, please? 
 

[The Tassie Devil(le)]

G'day Karel,

Personally, I wouldn't recommend buying oil from outside your own Country, as the postage of something as flammable as that would require specialised shipping, huge cost, but I even doubt it if they would actually ship oil overseas.

I couldn't even get a shop in Texas to ship tyre paint through the post.   They said it had to be in a shipping container, as in come by sea.

It is a bit like trying to ship pressure-pack cans through the post.   Highly illegal.

Bruce.

[Koa]

Oh guys - the question is not about shipping, but about oil: 

WHAT OIL IS THE MOST SUITABLE FOR THIS ENGINE ?   Outside temperature from -5 to + 30 C .

Just imagine, I live in Chicago or where ever .....

Plaese

[Eric DeVirgilis CLC# 8621]

Make sure to use zinc additive or zinc blend oil. 10W-30 or 10W 40 have the widest temperature range.

[35-709]

I would go with 10W-40 also.  SE is an old designation, best you could get at the time, get the best you can in today's oils.  Cadillac would have recommended an SJ rated oil or above for your engine, if it were available at that time.  As Eric pointed out, you want to make sure your chosen oil has zinc - ZDDP - 1000-1200 ppm, or use a zinc additive.  One caveat, too much zinc additive can be as bad as not enough.

SN - Current. For all automotive engines currently in use. ...
SM - Current. For 2010 and older automotive engines.
SL - Current. For 2004 and older automotive engines.
SJ - Current. For 2001 and older automotive engines.
SH - Obsolete. ...
SG - Obsolete. ...
SF - Obsolete. ...
SE - Obsolete.

[cadillactim]

For my 1960s and 1970s cars I use Valvoline 10w40 racing oil. It has the needed zinc in it.

Tim

[TJ Hopland]

One reason I was wondering what was available there is that maybe they don't have the same emissions rules there so maybe a typical oil there is better for old cars than what we can get here.   Seems like a waste of time and money to me to import a questionable oil plus additives from the USA.    There has to be something available there that would be at least as good as the crap we have here,  maybe even better?

In the USA we have the API (American Petroleum institute) that works with the manufactures to come up with the standards like the S's which are for 'spark' engines, in other words gas petrol.  There is also a C standard for 'compression' or diesel engines.  We also have the SAE which is Society of Automotive Engineers and they are the ones behind the 10w-30 sort of ratings.

What is commonly used in other brands of classic cars there?  I would guess 1970's European engines were not that different from USA stuff.   Maybe look into industrial equipment like maybe Zetor?  If its like the USA there are lots of old tractors around still running so maybe a classic tractor oil?   In the USA many of the diesel oils carry both S and C API ratings.   If that is the case there too maybe a diesel oil would be a good choice?     

Looks like the weather there is northern USA / South Canada so freezing temps in the winter and also has hot periods in the summer.  If you operate the car in freezing temps a 5w makes for quicker less unhappy starts.    If you go with synthetic or synthetic blends you can get a wider range like a 5w-40 which I think is a good choice for an engine that has to run in both freezing and 35+C (100f) temps.

[Koa]

What is the purpose of the zinc additive?

[64\/54Cadillacking]

What is the purpose of the zinc additive?

To protect the flat tappet camshaft and lifters from excessive wear. The older pushrod engines use a flat tappet design which need a coating of zinc/phosphorus A.K.A ZDDP to protect the harsh forces in mechanical wear on the cam lobes. Without the ZDDP additive, you can create pre mature wear (scarring) which can cause damage to the camshaft and lifters.

I know If I don't add a ZDDP additive to the oil of my 64 Cadillac, the lifters will make a bunch of tapping noises. The engine quiets down and smooths after dumping a bottle of Rislone ZDDP oil additive or simply using an oil within high amounts of it. 

Castrol makes a Classic GTX 20W-50 weight motor oil that has a lot of ZDDP in it and it's a SJ rated oil. Since it is conventional oil, it might not flow well in very cold temperature climates. But out here where I live in California, I can get away using 20W-50 weight all year around and it doesn't effect the my engine.

You can find it on Amazon here (this is a USA link)  I am not sure if your country carry's it, but it's worth looking into. Any kind of racing oil will work as well. Just make sure it has high amounts of ZDDP in it and your engine should last forever inside as those 425 CI Caddy motors are built like tanks.


https://www.amazon.com/gp/aw/d/B093RT3B1W?psc=1&ref=ppx_pop_mob_b_asin_title

[Eric DeVirgilis CLC# 8621]

What is the purpose of the zinc additive?

To lubricate lifter to camshaft points. As roller lifters replaced the flat type, zinc was no longer necessary.