Cadillac Owners Forum banner

1 - 20 of 24 Posts

·
Registered
1969 Coupe DeVille
Joined
·
120 Posts
Discussion Starter #1
I mostly use synthetic 5w-30 in my v6 cars with change interval 3K-5K (3500 mostly).

What is the recommendation for the 69 cadillac v8 (7.7L)? I am looking at the manual and it says temp 60F and above use 10w-40 and 20w-40 for 80F and above.

I am in CA and summer is usually 80+F.

Any opinions. This is my first V8 and it happens to be 7.7L!!!
 

·
Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
Joined
·
70,384 Posts
The "fleet" or "marine" oils use a higher anti-scuff additive package than the "energy conserving" automotive oils of today. Your flat tappet engine needs that protection. Look into the conventional Pennzoil LongLife 10W-30 or 15W-40 oils. Truck shops or marine stores. Also, the similar Shell Rotella series or the Chevron DELO oils.

Just because an engine oil carries a diesel service rating in addition to an API service rating does not mean it's no good for automobile engines. The diesel service says the oil will scrub and suspend a larger soot load than the "energy conserving" oils.
 

·
Registered
94 Fleet Bro, 64 Deville. Past: 72 Sedan, 68 Coupe Deville
Joined
·
587 Posts
Definitely, diesel oils do contain higher anti-wear additives and the 15-40 weight oils are perfectly fine to use in pretty much all V8 engines. I like to use full syn oil in all my cars regardless of age, so Rotella T6 or even Mobil 1 High Mileage oils that have the SL rating uses more ZDDP additives than their standard Mobil 1 oils do.

Valvoline VR1 Racing oil is also a very good oil to use in our older Cadillacs. You can find that stuff at most auto parts stores.

Before I forget, I was having a lifter tick in my 64 Cadillac that didn't go away even after warm up. I decided to add a half a bottle of Rislone engine treatment to the crankcase. To my surprise, about 5 minutes after the engine warmed up, the ticking completely disappeared! The oil was changed like a month ago, so dirty oil wasn't the problem.

Not sure what the engine treatment has in it, but it worked.
 

·
Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
Joined
·
70,384 Posts
Rislone, Wynn's Friction Proofing, Bardahl - others - have been around since I was a kid, working part-time on weekends in an outdoor grease rack at the local AMOCO station. The additives don't do much, if anything, for engine life but they DO contain some percentage of solvents, whether mineral spirits, Stoddard Solvent, or naptha.......... so it's possible that the Rislone loosened up a hydraulic lifter check ball/spring and allowed it to pump up better, or removed a bit of varnish on a lifter inner sleeve (tiny piston).

Using a good, modern engine oil and a WIX filter, I would not recommend dumping in additives on anything like a regular basis.

You want tough (but pricey) HD oils ? Look through the Joe Gibbs Driven oil site. Google it.
 

·
Registered
1970 Coupe De Ville//Cessna 172
Joined
·
551 Posts
Good topic.
I need an oil change after a rebuild. Trying to decide what kind of oil to put in her.
Lets get some posts on what everyone uses please. I want to find one kind and stick with it.
Jeff
 

·
Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
Joined
·
70,384 Posts

·
Registered
1970 Eldorado.
Joined
·
4,023 Posts
I am happy they sell classic car oil here
 

·
Registered
68 DVC, 96 FLTWD Brgm, 11 CTS Premium (two)
Joined
·
1,623 Posts
5W-anything is too thin unless you live in North Dakota.

I try to use 20W-50 Shell Rotella, or 15W-40 Rotella all year, but I'm here in FL. In MD either of these would be good until Oct or Nov, after which a 10W-something (preferrably Rotella or a diesel grade) would be good.
 

·
Registered
Something German S550, 69 Eldorado, 68 Impala, If I tell you the rest, well
Joined
·
529 Posts
Havoline 10-40, in winter have used 10-30 conventional, but brand doesn't matter, unless the motor speaks to me.
 

·
Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
Joined
·
70,384 Posts
The API service designation guides can be found with some Google work. This one goes back far enough.

Most "starburst" or "energy conserving" automotive oils will be pretty close to these ZDDP levels.

The fleet and marine oils do not meet the jackass EPA specs for ZDDP loading, so they are a better choice for older flat tappet engines.

A 20W-50 oil is too "heavy" for any modern automotive engine in street or highway use. 15W-40 is normally used in high load large diesel and marine engines.

As I posted earlier, look through the Joe Gibbs Driven oil site. They market conventional and synthetic oils for all older muscle car engines.
 

Attachments

·
Registered
1969 Coupe DeVille
Joined
·
120 Posts
Discussion Starter #16
I use 10W40 in my '69 and '76 Cadillacs.
Which brand? this is what I was thinking too.

----------

The API service designation guides can be found with some Google work. This one goes back far enough.

Most "starburst" or "energy conserving" automotive oils will be pretty close to these ZDDP levels.

The fleet and marine oils do not meet the jackass EPA specs for ZDDP loading, so they are a better choice for older flat tappet engines.

A 20W-50 oil is too "heavy" for any modern automotive engine in street or highway use. 15W-40 is normally used in high load large diesel and marine engines.

As I posted earlier, look through the Joe Gibbs Driven oil site. They market conventional and synthetic oils for all older muscle car engines.
Yes their HR Conventional 10W-40 is on my list.

----------

The Mobil1 high mileage 10W-40 is NOT specifically categorzed to use in flat tappet engines - any idea why that would be and they put that sticker or their 15W-50?
 

·
Registered
1969 Coupe DeVille
Joined
·
120 Posts
Discussion Starter #17
OK - decided to go with HR Conventional 10W-40 from Joe Gibbs. 20 buck more but once a year fill might be worth. Thanks all!!!
 

·
Registered
1964 Convertible, 1974 Corvette coupe, 1974 Corvette Vert
Joined
·
80 Posts
G'day,

I have a '64 429 and I contacted Penrite Oils in Melbourne Australia (I live there) and they recommended their Racing 10W-40. It is a full synthetic with about 1,500 ppm of ZDDP, well above the 1,200 ppm recommended for flat tappet engines. A 20 litre drum cost AU$270 (about US$190) or about US$9.50 per litre. Expensive, but a lot less than an engine rebuild.

Hope this helps.

Regards from Down Under

aussiejohn
 

·
Registered
1969 Deville convertible
Joined
·
107 Posts
10W-40 with a quart of oil substituted with Lucas heavy duty oil stabilizer. 300K miles and still going strong and still does not use oil.
472 in a 1969 deville convertible
 
1 - 20 of 24 Posts
Top