motor oil zinc content? 1971 eldorado.

[NORTHPORTGUY]

This topic has probably been discussed often but I have not found any threads....  i was at a car show yday where a vendor selling Shell X-100 gave me a convincing presentation that, that Shell's natural (vs. Syn) product meets the Cadillac motor oil standards for my 71 Eldo.  The manual specifies  oil meeting the GM standard 6041-M.  I am using AMsoil synthetic high zinc formula. The shell sales guy advised Amsoil zinc is around 600 PPM (i do not see anything that confirms that on Amsol packages/web site) vs his product having 2000 PPM.  He repeated the old saw that syn oil will cause leaks.  Are there any technical observations, studies available that clearly defines what is on the market today that matches GM 6041-M?

btw I am composing a question for the API but doubt they'll help
thanks Ken Wiebke
#23013
1971 eldo
2008 DTS
2013SRX   

[Jon S]

Standard dino oil - Quaker State or Pennsoil with 8 oz of redline Break In Oil will give you all the ZDDP your engine needs for a lot less money. Been doing it for years.

[Evan Wojtkiewicz]

I just changed my oil with Valvoline VR1 20W50. I used to do the regular oil with the additive, but I heard that it's better to use oil with zinc already in it. I saw the Amsoil at the store, and noticed that on top of being almost $11/quart, it was a full synthetic which is a big no-no for my already leaky 429.

[Scot Minesinger]

There is some point in time where engines were manufactured with valves that could withstand the higher temperatures of unleaded gasoline.  My understanding was that zinc was required to be added to oil of cars that were not engineered to operate on unleaded gasoline, but not cars that were engineered for the use of unleaded.  That written, I think 1971 was the first year that Cadillac manufactured the engines to run on unleaded (had a lower compression ratio).  You should research this idea, as you may not even need zinc.

I have a 1970 Cadillac which was not designed for use with unleaded gasoline, and just use the ZDDP additive at every oil change.  This costs about $8 extra per year over a 4k miles driven period, so it is inconsequential.

Further, I don't think , but do not for sure, if adding ZDDP to the oil would matter or not on a 1971 and newer Cadillac.

[Jon S]

There is some point in time where engines were manufactured with valves that could withstand the higher temperatures of unleaded gasoline.  My understanding was that zinc was required to be added to oil of cars that were not engineered to operate on unleaded gasoline, but not cars that were engineered for the use of unleaded.  That written, I think 1971 was the first year that Cadillac manufactured the engines to run on unleaded (had a lower compression ratio).  You should research this idea, as you may not even need zinc.

I have a 1970 Cadillac which was not designed for use with unleaded gasoline, and just use the ZDDP additive at every oil change.  This costs about $8 extra per year over a 4k miles driven period, so it is inconsequential.

Further, I don't think , but do not for sure, if adding ZDDP to the oil would matter or not on a 1971 and newer Cadillac.

Scot -

You are confusing the use of lead or lead substitute in the gasoline to lubricate the valves in pre-catalytic converter engines that did not have hardened exhaust valve seats with flat tappets that require ZDDP for the metal to metal lubrication of the camshaft lobes.

I did a lot of research with others and we found that the pre-mixed ZDDP oils as well as the pure ZDDP additives were excessively expensive when a 16 oz bottle of Red Line's Engine Break In Oil only required 8 oz to bring SM or later oils to previous SL ZDDP levels.  Redline costs $12./bottle. so for $6.00 extra per oil change you are all set.  Quaker State at Walmart is about $2.20/quart . . . cheaper in the 5 quart jugs.

Four of my five cars have flat tappet engines and I have been using Red Line's additive for years and all engines are whisper quiet.

[Dan LeBlanc]

Quaker State has a line called Defy marketed as for use in older high mileage engines.  Anti-wear additives are as follows:

Zinc = 1221 ppm (anti-wear)
Phos = 955 ppm (anti-wear)
Moly = 99 ppm (anti-wear)
Total anti-wear = 2275 ppm

I used to use it in my 63 Impala.  Seemed to be fine and that engine, at 75mph, with only a 2 speed transmission used to sing on the highway. 

In the 61 Fleetwood, I use Castrol 10w30 with an additive called Cam Shield.  I usually pick up a couple bottles when I'm at Hershey for under $20.  So far, so good.  I get the one-shot bottles, add it to my oil jug and shake it up before I dump it in the car.

http://www.cam-shield.com/index.html

[walt chomosh #23510]

Ken and fellow CLC members,
  When the controversy of zinc being taken out of motor oil due to catalytic converter damage,I noticed it on the container labeling. At the time,my research told me to add GM's breakin additive in order to protect camshaft lobes. I bought a case and began to use it regularly. Well,the first oil pan I pulled down told me to stop that practice! (it was caked in the bottom of the pan!) I then switched to Valvoline Racing Oil.(Lucas and others also make it in various blends,HIGH zinc content) My 2cents...walt...Tulsa,ok

[76eldo]

At the GN at Lake George there was a tech session on engines held by a race car engine builder.  He explained that in the early 90's all of the cars were being built with roller lifters and they do not require the zinc which protects the flat tappet cams and lifters on our older engines.

There is a lot of surface area contact between the bottom of the lifter and the cam.   He also stated that oils that are made with zinc perform better than using a standard oil and a zinc additive.

I have been using Lucas Oil in my older cars which is about $9.00'a quart.

I don't put on many miles and change the oil in the fall on each car.

There's not much benefit in using the synthetic and I doubt that the zinc additives will stay in suspension as well as the Lucas.

Brian

[TJ Hopland]

I was recently checking out a engine shop for a friend and they were pulling apart and engine that had a nasty build up in it.  I asked what that was from and they said it was likely some sort of zinc replacement additive.   They said they have been seeing that more and more recently.  I also asked if they knew how long it took to get that build up, they didn't know.  Most of their work apparently comes from restoration shops so they rarely actually talk to the customers.  I then asked how many flat cams they have been seeing and the answer was no change since he opened the shop in the early 70's.   He said flat cams are either cheap / defective cams or improper break in.   He did say if you were going to do a high revving performance build with a lot of spring pressure you should consider a roller setup.   Not something you need to worry about in a typical Cadillac that will rarely see 4k. 

The build up was not something I had even thought about but I suppose it could happen.   I remember reading the same thing would happen with some of the lead and octane additives back when that was what was going to end our hobby.    Guess the additive makers and sellers needed to find a more profitable crisis.  Zinc may not be it anymore now that pretty much the whole country has ethanol to worry about.   Move over lead and zinc the new engine killer is now ethanol!   Old news, my area has had the stuff for 20 some years now and for the most part we are still here with our toys.

I say use what ever makes you feel good.   There are just too many variables in an engine and how its used and maintained to likely be a able to prove anything either direction.   

[bcroe]

Besides the cars, there're many other older engines here.  They all get the
zinc supplement.  My only good test case is a 403 I have put 130,000 miles
on since the zinc issue; at 203,000 it still runs like new.  Whenever the pan
comes off I'll check for deposits; I have no faith whatsoever in the other
report where he know nothing of engine history.  Usually my long time
high mileage engines have pans with nothing in them but some oil. 

I don't care what zinc supplements cost, its cheaper than an engine.  And
when I run out of engines, a new car would REALLY be expensive. 
Bruce Roe

[Jeff Rosansky CLC #28373]

It is probably like most engine issues. If it just sits then it is bad. Running an engine and having reasonable oil changes is best. Many of these older cars dont drive much so they dont really get hot to burn stuff off. Then there is the old ' it only has 1000 miles on it, why do an oil change?' issue.
Jeff

[TJ Hopland]

Yep like I said too many variables.     

I just got my boat out last weekend and I think its been 3-4 years since it got an oil change.   Probably 10 hours of use all that time.   I'm sure its full of sludge, they only run at 120F and don't have a PCV system.  Add sitting a lot to that and it can't get much worse.  Gonna have to get that on the to do list. 

For the guys running the 20w-50 racing oil, hopefully you are in a always warm climate.   20w gets really thick when it gets cool out.   In the fall I was working on one of my trucks that had 15w-40 in it and had to take the lines off the engine oil cooler.  Ambient temp was high 30's F.   No oil came out of the cooler when I removed the lines.   Thought that was odd but it had been sitting a few days pointed up hill so figured it just drained out.  I shot some brake clean in it figuring that would flush it out that went in and didn't come out either.   Set the thing by a heater for about 15 mins then turned it upside down and then finally got a bunch of oil out of it.   I can't imagine how hard it would be to push that through a pump and bearings.    I found a 5w-40 synthetic blend I now use in just about everything.  Works good in the cold and when it gets hot.

[dadscad]

Ken, you are now using the best oil you can for your car. Amsoil will protect the vital parts and flow quicker on cold or hot starts than any other oil. Our cars can sit for long periods of time, you want the oil to reach vital engine parts as soon as possible when you start it up. Synthetic oil will flow to those parts quicker which will reduce the wear caused by dry start ups. TJ's experience using the 15-40 in near freezing temperatures is a perfect example why full synthetics are superior to refined petroleum motor oils, full synthetics flow when cold and don't break down under high temperatures. And, he is also right about using heavy oil where it isn't called for. Heavy oil can and will cause excessive wear if tolerances are tight, it just won't flow into tight spaces, especially when cold. Matter of fact, it won't flow into large spaces when it's really cold.

I've been using Amsoil HDD 5-30 full synthetic oil in my 63 for 75 thousand miles and many years. I have not experienced any adverse effects by using full synthetic oil in the motor, transmission or differential. I use Amsoil ATF synthetic transmission fluid in the Hydra-Matic and Severe Gear 75-90 synthetic gear oil in the differential.

[NORTHPORTGUY]

Very good discussion and thanks to all for your input.
One other interesting factoid: in looking over the manual page 0-20  it calls for an oil change EVERY FOUR MONTHS, never to exceed 6000 miles.  I probably change oil 2 X/year and consider that excessive for my very low milage usage. ....anyway  just as info.

Ken Wiebke
23013

[64\/54Cadillacking]

On my 64, I was getting a bad lifter tick "ta ta tat tat tat" even after an oil change using regular dino 5W30 oil.

Well I didn't realize the important use of zinc in the older 390-429 Cad engines or any pre 70's engines for that matter. So I changed the oil a second time and decided to use Mobile 1 0w40 European formula (great oil BTW) that has 1200ppm worth of zinc, with a bottle of Rislone ZDDP additive. Ever since then, the tapping has gone away. Maybe a slight rapping sound upon startup if the car hasn't been driven in over a week, but the noise goes away immediately within seconds.

I like synthetic oil due to it's longevity and longer lasting formula, the ability to really clean the engine, and it's great high-temp protection. As our cars do sit a lot, it's nice to know that the oil that's in all of my cars wont sludge up and get gunky in 6 months. I notice even though I don't drive my cars a whole lot, when I do an oil change, the oil is very dark.

I am not sure if that has to due with the richness of the carb or the oil not getting up to temp, or just moisture absorption from the lack of driving. I change the oil in my classics every 6 months just to make sure things are clean inside.

For people that are looking for an oil with a very high zinc content. Lucas Classic/Hot Rod oil has I believe 2,200ppm of zinc per quart. But it is very expensive. For a 5 quart jug it's like $50.00!

On these big ole Caddy motors, a 0w40 oil should be fine. It has the properties to flow extremely low at freezing temps, while protecting the engine at high temps cushioning parts better than a 5W30 especially during the summer time.

A 15-40 should work too in cold climate states, make sure it's a full syn oil, or you could possibly have start up issues.

[Scot Minesinger]

Here is my engine after 25k miles using the ZDDP oil additive to standard Pennzoil 10W40 (like you would have used back in 1970).  The ZDDP did not cause sludge.  The engine rebuild shop likely was guessing on why the engines suffered sludge build-up.  The sludge buildup is likely from when engine was new, oil maybe not changed regularly, and etc.

I think what causes most problems in our classic cars is disuse.  I was in high school when everyone was driving these 1960 and 1970 cars that are now classics and they were very reliable and nice driving.  Consequently mine are driven every week minimum.  This time of year likely they are driven three times a week.  In the winter when roads are salted, might have to go two weeks or maybe even three weeks of no driving.  Generally drive at least 3k miles per year in each classic.  That is why two or three classics is all I can manage.

[Jon S]

Here is my engine after 25k miles using the ZDDP oil additive to standard Pennzoil 10W40 (like you would have used back in 1970).  The ZDDP did not cause sludge.  The engine rebuild shop likely was guessing on why the engines suffered sludge build-up.  The sludge buildup is likely from when engine was new, oil maybe not changed regularly, and etc.

I think what causes most problems in our classic cars is disuse.  I was in high school when everyone was driving these 1960 and 1970 cars that are now classics and they were very reliable and nice driving.  Consequently mine are driven every week minimum.  This time of year likely they are driven three times a week.  In the winter when roads are salted, might have to go two weeks or maybe even three weeks of no driving.  Generally drive at least 3k miles per year in each classic.  That is why two or three classics is all I can manage.

Scot -

You are correct.  I can add that when I changed the valley pan gasket on my 1958 at approximately 82,000 miles there was no sludge or varnish . . . it looked like a 2,000 mile engine.  I don't use my cars as often as you, but upon seeing the lack of buildup over 50 plus years, I was impressed.  The car has had the oil/filter changed every 2,000 miles since new.

[Jeff Rosansky CLC #28373]

Moisture in the oil will kill you. Years ago I changed the oil in the plane. For some reason I did not fly it first and it hadn't flown in a week or so. That has a quick drain so when I opened it slowly, about a teaspoon of nice clean water came out before the oil. That is why it is so bad to just start them for a minute or so. If it doesn't get hot enough to burn the water off, all you are doing is getting water laden oil all up in the engine. Horrible thing to do.
Jeff

[64\/54Cadillacking]

That engine is spotless Scott!

Driving down the street and back is a big No No. I try to drive several miles in my classics to get them fully up to temp. Even a couple of WOT instances helps clear out any crap built up.

I don't think sludge is as big concern anymore like it used to be. With the oils today being so highly refined, they don't break down as easily. The biggest enemy is when the cars just sit forever. It's like your own body, if you don't move around, flex or stretch out, or even exercise you're going to feel stiff, achy and tired all the time.

People that live in places that have high humidity should really be more proactive on making sure there cars are driven often.

[Scot Minesinger]

Never less than a ten mile drive, most of the time 20 miles.  My car red Caddy (engine in picture) just turned over 128k miles today.