The Missing Zinc:

One of our fellow car cruisers brought this article to our attention. This is some really good information for anyone with an older vehicle or a muscle car about the type of oil used and the effects that the new emissions regulations have had on the oil that we use in our cars today.

Article From:  Popular Mechanics Magazine, October 2010 edition.

Car Clinic

By Mike Allen

Q+A

The Missing Zinc:

Q: I had a local speed shop rebuild the engine in my classic muscle car to as new to the original specs as they could, including all-new valve train, pistons, rings and bearings, I pre-pressurized the oil system, and the engine started right up. Within an hour’s driving, the engine started to lose power and misfire. One of the camshaft lobes had failed, making the egg shaped cam virtually round. There was a big divot carved out of the lifter boot. The shop says that I used the wrong oil and that I should have used a zinc additive as well. I used a premium oil, the same one I use in my new car.

A: Ah yes, the missing zinc. Let me start with a primer on zinc/phosphorus anti-wear additives: In the ‘50s, when cars began to feature overhead valves and started making serious horsepower, the camshafts needed more aggressive profiles, which were prone to rapid wear. That’s when lubrication engineers discovered the utility of zinc dialkyldithiophosphate (ZDDP), which had previously been used in motors as an anticorrosive additive in modest quantities. The phosphorus and zinc in this molecule are attracted to bare iron, coating the microscopic asperities (high spots) where the cam nose slides over the surface of the tappet. This molecule- thick layer prevents iron-to-iron contact. After a few hours of operation, the two surfaces burnish each other to a nice, smooth low-friction surface, micro-welding is a thing of the past, and everybody’s happy. Without the zinc and phosphorus, this localized high pressure, combined with the sliding friction, can microscopically weld the cam to the lifter, ripping out tiny chunks of metal. The industry standardized on 800 or so parts per million (ppm) ADDP content in motor oil, and engines lasted a very long time. In fact, ZDDP levels eventually rose to 1200 ppm by the ‘70s.

Cut the 1980s. Cars universally have catalytic converters installed to meet emissions requirement. Somebody figures out that zinc and phosphorus can contaminate the precious metal reactor beds in the cats, reducing their effectiveness. Concurrently, in an effort to reduce internal friction and improve economy, more and more engines use roller tappets or roller rockers, eliminating sliding friction at the camshaft-lifter interface. Even engines that have non-roller-bearing camshafts have better, upgraded metallurgy and improved surface finish at the critical cam lobe-lifter interface. ADDP levels were reduced to 1000 ppm, because the higher levels were no longer deemed necessary.

Now it’s 2010, and emissions requirements are even stricter. ZDDP levels have been reduced back to 800 ppm in the latest generations of motor oil, APE’s (American Petroleum Institute) AM and ILSAC’s (International Lubricant Standardization and Approval Committee) GF-4 spec. Even if some oil gets past the rings or the valve –stem seals in your engine and is drown into the intake through the PCV (Positive Crankcase Ventilation) vent, the cat will remain pristine and your exhaust will smell like buttercups.

And this is right where your ‘60s muscle car gets the shaft. Too little ZDDP, especially in the critical first few minutes of engine operation, can destroy the surface finish of the cam lobes and lifters, especially on the high lift cams, factory or aftermarket grind, used on the really fun cars. Lubrication engineers at Shell say that a stock engine with the original camshaft grind, stock springs with modest seat pressures and OEM-ratio lifters should fine running these 800-ppm oils. Aftermarket grinds, stiff springs and high ratio rockers increase cam-to-lifter pressures and would be better off with higher levels of ZDDP in the mix. Regardless of the petroleum companies’ take on this, most engine builders specializing in these specialty cars like to see that 1200-ppm number.

Back to your problem: Your engine builder should have provided you with instruction as to what oil to use, because there are options. Several companies make boutique oils that meet that high-zinc spec of yesteryear. Amsoil has several oils with appropriate levels of ZDDP in viscosities correct for your car. Some suggest using a modern diesel-rated oil—which I recommend against because there are a lot of additives in diesel oil that aren’t appropriate for spark-ignition engines, and vice versa. If you can’t find anything better at Walmart, however … Many mainstream petroleum companies have an oil marketed for older, high-mileage cars, and it usually has a healthy dose of ZDDP. If you need to know the ZDDP content of any product, ask for the MSDS (Material Safety Data Sheet) from the supplier, which will list everything in the bottle.

My favorite solution for veteran flat-tappet engines has been around for generations: General Motors’ EOS. It was originally sold as an engine oil supplement (get it?) for high-performance engines, and it has the correct amount of ZDDP in a form that wont plug up the oil filter. GM dropped this product a few years back, and I was hording my last six cans. Then it returned as EOS Assembly Lube, Not recommended as a Supplement for routine use, But only for breaking in a new engine. If that’s what it takes to get it past the EPA and onto the shelves, fine. There are other ZDDP products on the market as will. My favorite is Comp Cams’ Break-In oil additive, coupled with the use of GM’s EOS or Comp Cams’ Cam and Lifter Installation Lube.

One final though: It’s easy for the engine shop to blame the oil, but there are plenty of other potential issues that can wipe a cam nose. I like to assemble high-performance engines that have stiff springs, lots of seat pressure and high-lift cams a little differently. I leave out the inner valve spring and even substitute lower-ratio rocker arms for the first few hours. This will substantially reduce cam-nose-to-lifter pressures, reducing wear. After a few hours at lower revs, I change the oil to get out all the wear metal and install the rest of the springs and correct rockers. By then, the cam and lifter interface been broken in properly.

One important caveat: Do not add extra ZDDP additives to an oil that has sufficient ZDDP already on board, in the time-honored American tradition of “if a little is good, a lot more is better.” Excessive ZDDP is corrosive, and the optimal level is right around the 1200-ppm point already in most oils that meet the older standards.

A second important caveat: Oils marketed as racing oils may have a different additive package and may have less detergent, dispersant, viscosity-index improver and other good stuff in them. They’re really intended for racing, and their short drain intervals make them unsuitable for street driven vehicles. To confuse the issue, some products labeled as racing oil may actually contain the appropriate additive package and would be suitable for street use. Castrol GT Racing is one.

El-Camino & Ranchero Night

Wednesday, June 2nd, at 5:30pm is El-camino and Ranchero Night at the TopNotch Diner!

Hopefully the weather will play nice for us unlike this past Monday and we will be able to have a good night.

This is one of our new feature nights!

If you don’t have an El-Camino or a Ranchero, Come on down anyway. As always, we will be giving away two awards to any other registered vehicle that shows up.

We also have our new Dash Plaques! If you haven’t seen these you have to check them out. They are one of the nicer looking dash plaques I have seen.

In the event that the cruise night gets cancelled, a bulletin will be posted on the home page of this site. We didn’t post the cancellation notice this past Monday because it looked like we would be able to have the cruise. Just about the time we all got set up, the rain let us have it though.

Car Cruise Photos

All of the winner photos from each night of the cruise are posted on this site in the “The Winners are…” section. If anyone is interested in seeing more photographs from the car cruises I have my own website that I am posting my photography from the cruises on.

Car Cruising Photos

Work Truck Night At the Diner

The feature for tonight is Work Truck so shine em up and bring them down. Looks like we are finally going to have some great weather for a Wednesday Night cruise.
And remember, two of our awards will be given away to any registered car on the lot.
Hope to see you there!

The Winners Are…!

I have just posted a new page for the Winners of each night. The page has a slideshow that will display the photos that I take of the winners. This will be updated every time we have a cruise night.

Update.

The new schedule of featured cars for Wednesday Nights at the diner has been posted. Most of the information for the Bar and Grille has been removed from this sight.

The TopNotch Bar and Grille Is Closing It’s Doors!

“Saturday, May 1st, 2010 will be the locations last Day.”

This came as a big surprise to all of us when Garry announced that the Bar and grille would be closing down permanently as of Sunday. We had already printed flyers, posters and T-shirts all with the grille’s car cruise on them.

However, we have reprinted the flyers and are reprinting posters. We have decided to move the Wednesday Night car cruises to the diner and we have come up with a new set of feature car nights for Wednesdays and I will get the new schedule posted here as soon as I can. The flyers with the new schedule are already available at the Diner in Cortland.

The Eastwood Mall has received an offer from a large chain restaurant to move into this location and TopNotch was asked to vacate the premises.

So we hope that you will join us at the Diner on both Monday Night and Wednesday Nights.