synthetic oil in CCCA engines

Hi Gearboy:

The primary advantage of so called "synthetic" oils over "mineral" based engine oils is that they handle EXTREME heat somewhat better. At a recent seminar at OSHKOSH (airplane buff meet) the petrol industry guest lecturer told us that modern synthetics give you a good 30 degree safety cushion over and above the ASTM/SAE standard for mineral oils. I do use "synthetics" in my aircraft when I am going to do high-power take-offs from lakes here in Arizona, where air temps can be over 115, and oil temps. during "climb-out" over 250 f.

The DISADVANTAGE of "synthetics" is that they are not as good as holding the products of combustion in suspension. The engines of the past had much lower compression ratios than today, and as a result, were not as "clean burning".

Think of the products of combustion, as simply "ash" left over from a fire. This "ash" (carbon) has to go somewhere. In the old days, before modern additives, this "ash" would "link up" its carbon particles, and become sludge, sticking to engine parts, and causing all manner of mischief. Modern oils (both petrol. based and synthetics) will keep the "ash" in suspension, where it can be filtered out.

It is not likely that an ordinary water cooled automotive engine, especially one with a big long oil pan like yours, even under extremes of speed and outside air temp, is capable of raising its oil temp. to levels that would warrant the expense (and possible risk of "over sludging" ) of synthetics. Remember, ANY modern "approved" engine oil is going to be vastly superior to ANYTHING you could buy back in the classic era.

If you pick ANY off-the-shelf 10W-30 for winter, and 20W-50 for the REALLY hot high speed runs, you will be just fine. SAE/ASTM standards (along with a host of liability concerns) means 1) you cant buy a bad engine oil today...and 2) they are ALL compatible with each other.

I STRONGLY recommend to ANYONE operating an old car, that the FIRST thing they should do on first receiving it, and then, religiously, at least every other year...DROP AND CLEAN OUT THE OIL PAN !

This gives you a chance to check that the bearings are doing nicely, and also, clean out the inevitable sludge that is the product of combustion.

As a side-note, the oil company advertising people played a little "joke" on us when they came up with the term "detergent" oil. Of course there is no such thing as "detergent" oil. True, for the first few months that "detergent" oil was on the market, there were STORIES that it somehow "washed down" sludge, but, even if true, that was resolved by the early 1950's, when I started using the stuff in my Packard Twelve (along with endless numbers of other big engined cars of various makes our family owned.

I pulled the engine of the V-12 down for an overhaul in '56, and, as an experiment, left a small pocket of sludge on one of the crank throw balancers, and another up in the side of the crank-case. THOSE SLUDGE POCKETSD ARE STILL THERE ! That should pretty well demonstrate, that even under the severe operating conditions I LOVE to drive my car in, "cooked on" sludge is NOT affected by the so called "detergent" oils.

Bottom line...EVERYONE...1) drop that oil pan at least once a year if you use that old car regularly, and 2) use whatever multi-grade oil is on sale that day...and you will do just fine !

Pete Hartmann

Thanks for your insights, Monsignor Hartmann. You're absolutely right about ANY of today's major brand conventional motor oil (and even downmarket discount brands) being night and day better, intergallactically better, than the BEST motor oil available in the '40s. I realize synthetic's big draw is handling extreme heat, and today's conventional oils protect the driving we do in our relatively low-compression engines. Mine's been tweaked to 7.5:1, but that's still moderate compared with most modern engines. My Packard 356 was hot-tanked, etc. before it was completely rebuilt, and has always had high-grade conventional oil, changed often.

I and others wonder if our thoroughly rebuilt Packard and other CCCA-era engines would derive any appreciable anti-wear benefit from switching to today's synthetic (or synthetic blends). And, if so, would our seals handle synthetic oil? Rebuild gasket kits still furnish the same rear main seal material as used when our engines new. We'd heard from another fellow, albeit 20 years ago, like you both an old car driver and pilot/retired aero & auto mechanic, that once seals leaked due to synthetic oil, switching back to conventional would not stop the leaking. But this was when synthetics were still new to most of the market, and why we hoped to hear from anyone using them in old engines today.

Read one of Smokey Yunick's columns (Motor Trend?) 10 or so years ago, in which he recalled a NASCAR engine running synthetic oil torn down after a 500-mile race (equivalent to thousands of "civilian" miles), and you could still see the honing marks on the cylinders.

This thread may seem like overkill to many of you, but some of us are always looking for the best ways to provide our wheeled alter egos with the utmost in both preservation, as well as protection for those occasional banzai runs.

Thanks again for your experience, and the business about the sludging, which may be reason enough to stick with conventional oil? Meanwhile, would we see

tangible wear protection, and would TODAY'S synthetics be compatible with our seals?

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I agree with Peter. The most exotic syn. I know Shell 0-60 is specified for the new Ferrari Enzo. (It costs $60 a quart) It was designed for that engine which makes 660HP. Modern High Output engines were designed to use these type of oils.

In a CCCA era car I suspect they would leak through seals and gaskets. I like Peter found the oiling system of my Duesy in need of cleaning and I'd also reccomend changing the filter element to a more modern one rather than the paper/slinkey. When I cleaned my system and replaced my filter I got much more oil PSI. I use 50W Castrol in the Dusey. In my 60's race cars I use 40W Castrol. Synthetics leak through those engines as well. In Peter's plane where the oil temp reaches 260 syn. is the way to go, as it is in Marine engines which can also get very hot (I've seen 280 in my race boat) but in CCCA era cars I'd use dino oil.

Hi, Gearboy:

I believe a couple of your assumptions are in error. First, your post suggests that "discount" oils may be "different" than name brands. If that is your inference, your assumption is incorrect. Here's why. "Discount" oil refineries? You mean you didn't know ? There are only a few refineries with the technology to make modern motor oils, and about the only thing that is "different" in their products, is the plastic cans the product comes in ! One week they may ship out the product marked "brand X", the next week, "Joe's Super Discount Brand Y".

If you look at the can of ANY multi-grade oil you buy ANYWHRE, you will see a label that lists the various tech. standards the oil comples with. Given the disastorous legal consequences if the product failed in service, and/or failed to meet the specs., it does not seem likely to me that any distributor would "take a chance" on a sub-standard oil (that is..IF there was a sub-standard oil that carried the label "meets all specs..etc". (which is another DURN good reason not to use so called "non detergent" oil - it does not represent that it meets ANY standard - it use should be limited to keeping the blades of your lawn mower from squeaking....!).

Your "post" indicates you have concerns about engine wear. With modern wear inhibitors found in ALL "approved" motor oils ( they HAVE to be there, as they are VITAL for SOME machines where the engine lubricating oil also lubricates transmissions) wear is no longer significant.

Well...that is IF you change it and filters once in a while! Over-haul intervals back in the classic era were typically in the 30,000 - 60,000 range. Now, MUCH greater. Light vehicles in commercial service, where oil and filter changes are dictated by company shop policy, consistantly go 300,000 mi. + without opening up the engine, with heavy duty engines, double that.

I have no doubt that under laboratory conditions, it can be demonstrated that the "synthetics" are "superior" to mineral based "approved" oils. As we discussed earlier, I dont think you will find real-world advantages over ANY "approved" motor oil compared to any other "approved" motor oil in any automotive-type engine.

As you note, your "356" is a relatively low compression engine, so it is not going to be burning fuel as efficiently as a modern motor. There will be more "products of combustion" getting into the oil. But you sound like a particularly "with it" guy, I suspect you will be changing your oil at regular intervals.

Yes, your "356" is also a LONG stroke motor, meaning the piston speed and rod bearing loads are MUCH higher than those in modern motors, which in theory means more wear. But again, you can be confident that with the incredibly superior "wear protectors" in modern oils, your KIDS arent going to live long enough to wear the thing out !

Pete Hartmann

Pete, Thanks for your excellent posting regarding motor oil. For many years I owned a Mercedes 450SL and religiously changed the oil with Mobil 1 synthetic at about 5000Km or less usually depending on time rather than mileage. The engine internals were as clean as when the car left the factory after 200000Km. I was convinced that the synthetic was a superior product to conventional oils. This car of course ran quite hot and had a 8 liter oil pan so quite expensive (but so would a new 450 engine!). I have been thinking of trying Mobil 1 in my Packard Super Clipper(also with the 356 engine)as well but I didn't realize that conventional oils are better at capturing combustion deposits. I am wondering if an oil such as Shell Rotella which is specifically blended for Diesel engines would be a better choice since they would probably have an even higher amount of combustion deposit control additive. What are your thoughts on this?

re: "diesel" engine oils

At the risk of repeating myself, I again recommend to all my auto buff friends, that when they get some free time, go to the MAIN branch of your city's public library, where you will (hopefully) find back issues of the SAE JOURNAL. If you are lucky, you will be able to find issues going back to the twenties. The articles are typically written so that us laymen can understand what they are talking about. I can't imagine a more efficient way of bringing one's self "up to speed" on auto-related technology issues, and how the technology has evolved thru the years. Sorry about that little repetative "speech-making" but I feel strongly about this, great way to separate the "old wive's tales" from good info.

Now, regarding your specific question:

Again, I do not think it possible to buy a bad engine oil in this country, that says "multi-grade-meets all engine maker's specs". And, dont fall victim to the advertising "hype"...they ALL must meet certain standards, thus they ALL have the wear-inhibitors that have pretty much made engine overhauls a thing of the past for most of us.

So called "diesel" oils ? They USED to call these "Series Three" oils, for their special inhibitors. These inhibitors were designed to control engine damage due to the high sulphur content of the older diesel fuels. There are still some special additives in diesel engine oils, but, again, they are designed for the special problems of diesel fuel - I don't know that they would do any harm, but you certainly would not gain any advantage.

Multi-grade oils were already in useage when I started beating up my Packard Twelve back in the early 1950's. I generally drive with two throttle positions...OFF when I see a pretty girl in a low cut dress, and WIDE OPEN for my idea of normal driving. So far, the Twelve seems to be O.K...!

Seriously, you and I do have the same problem in that we have relatively inefficient long stroke low compression engines. For that reason, I personally think it is wise to "drop" the oil pan every couple of years, and clean out the bottom of the pan (for those who are wondering what we are talking about, many of the older "collector car" engines had VERY long wide oil pans, that do NOT drain as completely as the "modern" short stroke V-8's that started appearing in the late 1940's. You just dont get all the dirty oil out in these older engines.

Sounds like you did a pretty thorough job of over-hauling that 356 (for those who are wondering, that was the "big" eight cylinder motor Packard used in its more expensive product line from 1940 to ..hmm..not sure...think it was '49, as I BELIEVE the 1950 Custom with Ultramatic was the 327..a smaller, less powerful motor).

Again, I rather doubt if you or your kids...heck..even your grand-kids...given modern oils...will EVER wear the thing out! I presume your car has operable over-drive, so it can cruise at 75 mph all day long...it will be "loafing" at that speed.

Pete Hartmann

Pete, Thanks onec again. you are a bit pedantic but i appreciate your frankness never the less. Yes I dropped the pan on the big Packard this summer and flushed out what sludge there was. i agree it wouldn't be a bad idea as you say. I recall reading that Packard tested the 356 against the 12 and the 8 one. I am just ribbing you. I know they geared the 12 down so she couldn't catch the 8 . In overdrive this car will do 90 in second and a tad over 100 in top. <img src="http://www.aaca.org/ubbthreads/images/graemlins/smile.gif" alt="" />

i agree with edselv12, i too try and drop the pans in the older cars at least once a year, but in my lagonda V12, it involves undoing about 70 odd nuts!!

I have never seen a Lagonda V-12 ! What can you tell us about them ? What was their displacement, bore and stroke ? How were the cars geared ? Sadly, we had little exposure to European classics out here in the far west (ooops..I mean..western part of Hollis Hills, Long Island, New York) during those delightful early years of the Classic Car Club Of America.

Of course I am partial to the large displacement "heavy iron" American classics. Tell us more about what to many of us Americans, is a mystery.

"Dog Spot"

I saw a complaint about a smoking Lincoln V12 on another post. Do you think that the non-ash producing value of synthetic would be worth while using as a stop-gap to a smoking engine with poorly seated rings? I know from experience that using syn in a wounded engine will reduce smoke substantially, at least for a while. In the case of breaking in poorly seated rings, will the syn oil adversely reduce the "break-in"? In other words does syn oil have extra lubricant quality which might adversely effect "break-in"? Some vintage/collectible cars with marginal cooling systems might bebefit greatly from the protection of syn oil (like Jag 120s).

Bill C in TN

Advice from several engine buiders to me over the years has been to break in a fresh re-build on petro-based engine oil before contemplating a switch to synth oil as the greater lubricating properties of the synthetic may not allow the rings to seat properly. It is further my understanding that an engine run from new (rebuilt) on synth will hazard not seating the rings properly, although Dodge Viper, and others of that ilk come factory filled with synthetic oil. It is probable that those higher-performance engines have undergone extensive bench break-in or simulated running before installation. To be blunt, I'd run the Lincoln hard on dino oil for a few oil changes b4 it saw a drop of Mobil1, if ever.

These old engines, whether classic or simply vintage, are for the most part loafers; i.e., long stroke, low rpm, low compression, heavy iron. Certainly there is fine engineering and assembly involved, but the high heat and loads visited on today's small, highly-stressed engines does not apply.

In my opinion, a good national brand petroleum-based motor oil meeting standards for use in gasoline engines is well beyond adequate for the average vintage/classic/antique engine that is used under normal circumstances. Using oil of a higher specification is not harmful or particularly helpful but will add to the cost of operation. Synthetic does have a flatter viscosity curve with temperature change, but keeping the engine cooling system operating properly accomodates petro oil.

Expecting oil in itself to remove substantial or even marginal amounts of excess heat will probably result in disappointment. An auxiliary oil cooler would do more, as would an upgraded water-cooling system. Jags of that era typically needed help in that department, as I recall.

Today's conventional oil is definitly far better than anything that they had back in the 40's. I think you would do fine going with just straight oil and not the synthetics. Synthetics are really meant for the high compression, racing, weekend drags. My personal experience with synthetics, with a classic everyday driver, were not good. The synthetic burned out what was holding the cylinder wall together, and did not fill the cracks, divits, little nicks back in. Making it a whole lot rougher in there. Then if it gets too bad then it passes the rings, then a whole other problem. Of course I switched back to regular oil before that happend. Since there are long periods inbetween driving, engine being newly restored, you change regularly, I wouldn't forsee a problem with regular, mineral based oil. Especially being an older block, metalergy being of 40's chemistry.