Zinc in motor oil?

jdp8402

Member
My local mechanic told me that I should run a motor oil with zinc in it. Is this true? He said that it has something to do with the old bearings. If I should be running oil with zinc can anyone recommend an oil ( brand and weight ) with zinc already in it? I know I can buy a bottle of zinc additive.

Thanks,
Jeff Perry
 
Jeff,

Model A engines need zinc as an anti-wear agent. There are threads that go into the technical details, so I won't go into it here. You can buy the additives separately, or there are oils that have the additives already mixed in. I have been using Brad Penn (Penn Grade1) It has the Zinc and phosphorous additives already mixed in. Others will have their own preference, but I am very happy with the performance of this oil. I buy it through Amazon.
 

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As has been said before, the Model A doesn't need zinc or actually phosphorus.
Original oil didn't contain phosphorus, the cam didn't require it then or now.

A's Always
Dave
 
Jeff,

Model A engines need zinc as an anti-wear agent. There are threads that go into the technical details, so I won't go into it here. You can buy the additives separately, or there are oils that have the additives already mixed in. I have been using Brad Penn (Penn Grade1) It has the Zinc and phosphorous additives already mixed in. Others will have their own preference, but I am very happy with the performance of this oil. I buy it through Amazon.

Really good oil, also easy to get through jegs.com or summitracing.com
 
As has been said before, the Model A doesn't need zinc or actually phosphorus.
Original oil didn't contain phosphorus, the cam didn't require it then or now.

A's Always
Dave

You are 100% right, Dave! This zinc myth just won't die! Any modern oil will work just fine; they all have more than enough additives for an A, including zinc. Maybe if you have high pressure valve springs to turn 6,000+ RPM or more, you may need the zinc. Otherwise, let this myth die a deserved death!
 
Cams have a thin line of contact with the tappet, and in addition the contact is a wiping action as the cam lobe scrapes across on the flat tappet surface. The Model A has relatively light valve springs compared to modern engines, but I still feel any added protection can only benefit the engine and retard wear. I like oil with zinc and also use Rotella 15-40.

Modern cams use rollers against the lobes, so the zinc isn't needed, and the catalytic convertor also can't tolerate the zinc.
 
Thank you all for the replies. I'm not trying to get any arguments started, I was just wanting to know if this is something I need or not. I think I agree with Tom Wesenberg. It may not need the zinc but if it does help even a little bit then why not. If there is a $20 per quart price difference then I probably won't be using it.

Thanks,
Jeff
 
Read Lake Speed's son's article about oil. He is an oil specialist engineer for Joe Gibbs racing. Detergent oil actually removes the zinc layer, which has already correctly been said really in not needed in old cars.
 
Most Diesel motor oils (like Rotela T) have higher levels of zinc and are quite reasonable, I just use Co-Op DMO 15-40 in all my old engines and it runs about $4 per litre (Canadian $) If you look around places like Tractor Supply and big truck shops usually have DMO on sale a few times a year.


Looking for the front bumper emblem that has "Ford, Made In Canada"
 
ZDDP really does nothing for you in a Model A Ford engine. ZDDP was developed to combat scuffing wear experienced in ultra high performance engines that became available in the 1955 model year. The scuffing was destroying camshaft lobes and lifters when valve spring pressure exceeded 300 pounds open pressure.

Forces in a Model A Ford engine do not approach these numbers, so it is a non - issue. It's sort of like using Perrier in your radiator - it will cost more, but won't affect anything. Any modern oil of appropriate viscosity for the ambient air temperature will work fine. Just change the oil frequently to keep it clean.

If you have a muscle car with lots of valve spring pressure and a flat tappet cam, by all means use an oil with good ZDDP content.

My local mechanic told me that I should run a motor oil with zinc in it. Is this true? He said that it has something to do with the old bearings. If I should be running oil with zinc can anyone recommend an oil ( brand and weight ) with zinc already in it? I know I can buy a bottle of zinc additive.

Thanks,
Jeff Perry
 
ZDDP really does nothing for you in a Model A Ford engine. ZDDP was developed to combat scuffing wear experienced in ultra high performance engines that became available in the 1955 model year. The scuffing was destroying camshaft lobes and lifters when valve spring pressure exceeded 300 pounds open pressure.

Forces in a Model A Ford engine do not approach these numbers, so it is a non - issue. It's sort of like using Perrier in your radiator - it will cost more, but won't affect anything. Any modern oil of appropriate viscosity for the ambient air temperature will work fine. Just change the oil frequently to keep it clean.

If you have a muscle car with lots of valve spring pressure and a flat tappet cam, by all means use an oil with good ZDDP content.

Royce has it right!
 
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