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By Jeff Zurschmeide

You’ve just spent thousands of dollars on your freshly rebuilt engine, and more hundreds to get the carburetors, starter, generator, and other parts back to as-new condition. Now, as you install your engine and prepare for the big day when you start up your restored car, you need to choose a motor oil. You also need to select gear oil or automatic transmission fluid and lubricant for your car’s drive axle.

The first rule is this: if your engine builder recommends a particular oil, use it. Likewise, ask your engine builder about recommended additives and use them as directed. If you have heard of this or that additive (see the interview on this topic) for your oil or for your fuel, ask your engine builder before you introduce any product to your engine.

In the modern world, we are blessed with a wide variety of quality oil and lubrication products. These products protect our cars to a level undreamed-of in decades past. They are a gift of technology and research into quality improvement and emissions reduction.

But classic engines require careful attention. The engine in your new car is made to accept synthetic motor oil from the first start, and it needs nothing else. The metals in your new car’s engine have been designed to work well with modern synthetic oil formulations. The metals and clearances in your classic were designed quite differently.

One of the keys to a classic engine is that the original designers assumed that the car would be run on natural oils. Cars made before the wide acceptance of multi-grade oils were built to run on straight-weight generally non-detergent natural oils. You should still plan to run your engine on its original oil during the break-in period, so that the moving parts wear in together. After the break-in period, you can switch to a synthetic oil for maximum protection.

One question you should ask your engine builder is whether your engine requires ZDDP (Zinc Dialkyl DithioPhosphate) for protection. This chemical used to be added to almost all motor oils, but was eliminated to improve emissions control. The Zinc would be deposited on bearing surfaces (such as cam lobes) over time, protecting the metal from erosion. New cars don’t require ZDDP, but if your old car needs it and you don’t use it, you can end up with unreasonable wear in a short time.

Another key to good engine maintenance is your oil filter. Replace it every time you change your oil for best results. Modern spin-on oil filters flow better and filter better than their NOS vintage counterparts. If your car is a 100-point showpiece, you’ll want the original look, but if you plan to drive your car, get a modern filter on there every time.

Transmission fluids are also key lubricants. Your transmission rebuilder or your car’s maintenance manual will recommend a transmission oil for you. Use the recommended oil and any additives recommended by your builder or your manual. In general, most manual transmissions use either gear oil or motor oil. Rear axles almost always use gear oil.

Automatic transmissions use a different type of lubricant known by its red color. ATF (Automatic Transmission Fluid) has two main variants: Type F and Dexron. There’s a lot of conflicting information out there, but the facts are that Ford used Type F fluid through 1977, and then joined the rest of the industry in using Dexron. There have been other types and specifications of ATF, but Dexron is generally considered universally safe to use. Check with your transmission restorer if you’re not sure.

The last word on lubrication is just this: using fresh oil on a regular basis is critical to maintaining your restoration. Even if you’re not driving your car, the combustion by-products that end up in your motor oil develop acids just sitting in your sump, and these acids eat away primarily at your bearing shells. Change your oil at least every 3,000 miles or every 6 months no matter how few miles you’ve put on the car. A regular maintenance schedule helps keep your restoration happy.

Dos and Don'ts
Thumb up  DO
  • Change your oil regularly every 6 months or 3,000 miles - oil accumulates acids over time, even if you’re not driving.
  • Use a ZDDP additive for your classic car, or an oil formulated with ZDDP for classics
  • Always change your filter element with your oil
  • Use the grade and brand of oil your engine builder recommends

Thumb down  DON’T
  • Don’t mix synthetic and natural oils
  • Don’t use old-fashioned single-weight oils except during break-in - modern formulations are better
  • Don’t ignore oil leaks on your restoration - they cost you points
The Popular Restorations Feature Car
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1946 Packard: Lubrication



With respect to lubrication, the Popular Restorations feature car was pretty straightforward. Under the advice of Packard Club members and a couple of repair shops I used standard 90W gear lube for the transmission and differential and standard chassis grease for the suspension fittings.

The engine needs more zinc than modern oils contain (see related articles on this page) so I went with Brad Penn, Penn Grade 1 High Performance Oil. They have a break-in oil which I have replaced with a straight 30W.

The front timing cover seal is an odd one. It is made of cork and is pushed forward (from within) toward the inside of the timing cover by a spring and circular plate. When you install the front pulley you have to make sure that cork seal is perfectly centered so the pulley collar doesn’t injure it. The Packard manual recommends a special tool which is no longer available--I just eyeballed it and it worked fine.



Foreign Parts Positively

By Jeff Zurschmeide

Keith Ansell, Owner
19900 NE 189th Street
Brush Prairie, Washington

Keith Ansell has been running Foreign Parts Positively for over 30 years, and his experiences rebuilding hundreds of classic british sports car engines led him to research how the changing formulation of motor oils affects all engines built before the advent of catalytic converters. What he discovered is surprising, and may save your classic engine!

PR: What’s the story on motor oils? Aren’t they all about the same?

KA: There’s a government requirement that every modern engine and its emission control components must last at least 100,000 miles. Zinc and phosphates degrade the oxygen sensors and the catalytic converters on modern engines. So the oil makers have removed ZDDP (Zinc Dialkyl DithioPhosphate) from the motor oils that are commonly sold in stores. The API specification for motor oil won’t allow it any more.

PR: Why is this an issue for older cars?

KA: ZDDP was used for over 50 years. Because of very high pressures between the cam and tappets. Engines were designed to use oil with ZDDP. The zinc is deposited, compliments of the phosphate, on the cam lobe and the follower to provide a sacrificial barrier, to prevent metal-to-metal contact. It may also improve ring contact.

PR: So what oil should we use for our older cars?

KA: Your older car needs over 1200 PPM (Parts per million) ZDDP. Right now, there are only two mainline oils that meet this standard. Those are Castrol Syntec 20/50 Classic and Valvoline VR1 20/50. It’s important to get the Syntec 20/50 Classic, and not the general Syntec 20/50 if you choose the Castrol. Remember that the Valvoline is a natural oil and the Castrol is synthetic. Also, Joe Gibbs Racing Oil is now producing street oils that seem the best available for our engines and distribution of this product is just starting in North America. Red Line Oil, a smaller manufacturer on the West Coast, is available at many racing shops, with 10W-40. Eastern States seem to be able to find Brad Penn Oil, Swepco and Hi-Z.

PR: Is this true for all engines?

KA: Some diesel engines need ZDDP on the wrist pins. We used to be able to use Delo and Rotella diesel oils until about a year ago. But now they’re putting catalysts on diesels, so those oils are out.

PR: Is this just for break-in, or throughout the life of the engine?

KA: The whole life of your engine. But break-in is a whole different story. You still need ZDDP, but you don’t want a modern oil. Oils are so much better now than they were in the 60s and before, that our cars won’t break in on a modern oil. So we used Castrol HD30 for break-in, for 3,000 miles. We add ZDDP and use cam lube.

PR: Are there additives you can use to put ZDDP in your oil?

KA: I like two additive products on the market. One is Cam Shield, made by a startup company, led by an expert chemist and spun off of a racing enterprise. We’re the west coast distributor for Cam Shield. Another product is ZDDPlus. ZDDPlus was made back east by a place that specializes in turbo Buicks.

PR: What does it cost?

KA: The two manufacturers are comparable. It costs about $9 to $12 per 5 quarts to treat the oil correctly.

PR: With the additive, can you use any brand of oil?

KA: First of all, multi-grade oils are vastly superior to single grade. The other thing is detergent vs. non-detergent oils. People should use multi-grade detergent oils unless they have a brass era car - 1918 or earlier. For most all old engines, we like 20/50. Other than that, it’s mostly just branding and the additive package that makes a difference. So use any oil you prefer. If the automaker says to use Castrol, then use Castrol, but put your ZDDP additive in. One exception: If you have been running a non-detergent oil it might be advisable to stay with what you have been using until a new engine is built.

PR: Is there anything else we should know?

KA: For the cars that use engine oil in their gearboxes, the lack of ZDDP may pose a problem, as these additives could be very critical in preventing gear wear. We will be using oil specifically formulated for manual gearboxes with brass synchronizers. The only oils we are aware of that fit the criteria are from General Motors and Redline.

Click on any item below for more details at Amazon.com

Dan Ramsey, Judy Ramsey
Teach Yourself VISUALLY Car Care & Maintenance
Visual, Spiral-bound, 2009-04-27

(Note: For detailed information on engine oil, see the External Links section, below.) This book provides crystal-clear instructions on how to change oil and other fluids, rotate tires, replace fuel pumps, air filters, and batteries, and much more. An easy maintenance guide helps you keep track of recommended service and maintenance tasks at key mileage and time intervals.

External Links

There is an excellent detailed article on engine oil at CarBibles.com.

You can download the book Motor Oils and Engine Lubrication for free at www.motor-oil-engineers.com.

Here is a link to the ZDDPLUS web site: www.zddplus.com.

Cam-shield also sells a ZDDP additive: www.cam-shield.com.

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