Speaking of motor oil...

[Bobs29ModelA]

I'd stumbled across a posting some time ago, where someone had shared the key points of an oil seminar that they had attended. One of those key points was that we should be using an oil in our cars that still contains a Zinc additive... because the older cars (equipped with flat tappets) were designed to expect zinc in the oil, which was a major anti-wear additive for these tappets. The newer oils no longer contain zinc additive, which can apparently be detrimental to the Model A valve train.

As part of the seminar, an oil that was recommended was "Brad Penn Racing Oil", in a 30 or 40-wt, as it is one of the few oils out there that still contains the zinc additive. I've started running the 40-wt version in my engine, and it seems to do just fine. I was wondering, however, if anyone else has heard of this requirement for zinc?

[700rpm]

Bob, there must be a thousand posts on this topic. Try a search and if you don't find what you're looking for, check back in.

[1928Pickuppain]

I don't know why but I have never herd of needing zinc in my oil is there say a zinc additive such as an stp adoring or something that I can just poor in as top it off like people do with lead additive only reason I ask that is cuz if I had to buy a special expensive oil I'd go broke cuz I go though 1-2 quirts a day ( have a masive oil leak at the moment that I don't have the energy or time to fix)

[Tom Wesenberg]

1-2 quarts a day! That will keep you broke, but should hold down the dust on the roads.

There is a zinc additive you can buy, but first I'd fix that oil leak. You must have a rust hole in the oil pan to leak that much oil.

[Drive Shaft Dave]

I'm no expert on oil but I dont think the Model A need's the Zinc in the oil , with the low valve spring pressures on the cam There is no problem, the zinc additives were not introduced until the late fifties the A Bone got along with out it way back when don't worry about it now.

[LSGUN]

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^ correct

[Mike V. Florida]

No engine builder here on this site, and there are many, has ever shown a damaged engine that they say was caused by lack of zinc. If you still feel the need, purchase oil rated for diesel engines as it has more zinc then that for automobile use.

[Patrick L.]

I also don't believe our low valve spring pressure engines need zinc.. If you want zinc, then there are additives or just use diesel oil.. I wouldn't use racing oil in a pax engine unless I absolutely had to..

[Jim Brierley]

Correct!!! Also the A cam is steel, not cast iron like more modern engines. Present oils do contain some zinc, at about the level it had in the 60's & 70's, more than enough for our A-bones.

[Old182]

Good advice all. When Model As were being built, there were NO additives in motor oils. Todays API oils contain detergent/dispersants to keep engines clean and particles in suspension, antiwear agents to keep parts separated and slippery when they are not, friction modifiers that are closely related to antiwear agents, pour point depressants that allow oil to flow at low temperatures, corrosion inhibitors that prevent rust, antifoamants for obvious reasons, oxidation inhibitors to prevent thickening over time and at high temperatures, and viscosity index improvers to create multigrade oils from straight weight. Interestingly, zinc dialkyldithiophosphate (ZDDP) was originally used as an antioxidant in the early 1930s (but after Model A production) before it was known that it could also be used as an antiwear additive (another useless tidbit). It's your money and your engine; use a good branded detergent oil, but don't worry too much about the lack of ZDDP; enjoy the car.

[columbiA]

You dont need to add a Lead additive to the gas either or bother with hard valve seats as you are just throwing your money away. If you had a muscle car with 10 to 1 CR then you would need it.No need for ZDDP either.

[Bobs29ModelA]

Hmmm, interesting that just about everyone here says we don't need it. I wish I could find the article again, where the seminar was discussed, but in any event, the message presented by the oil "expert" was that we needed it.

Anyway, thanks for all the input; I guess I won't worry about it then!

[Patrick L.]

There was also a time when the 'experts' said smoking was good and healthy as well as giving patients cocaine and opium.. Even today, 'experts' disagree..

[Tom Wesenberg]

ZDDP may not be needed, but my feeling is that it can help, so I'll try to use the oil that has it.

Lead is not needed and can not help so I've never worried about it. In fact spark plugs and oil benefit without the lead in the gas. Dragsters, or tractors pulling a 6 bottom plow work hard and will need hardened valve seats, but the Model A and most everyday cars do just fine without special valve seats and without lead.

[Dick So. Cal.]

Take a look at the site: Bobistheoilguy.com. Lots of interesting info, especially about multigrade oil and what it all means.

Dick

[V4F]

not to disagree with the experts , but ZDDP is a important additive . i use valvoline vr-1 because i believe its one of the last oils with ZDDP . just my research & opinion ........ steve

[BILL WILLIAMSON]

My observation on motor oils: Yes, there are some oils formulated for special engine types, but there is no "MIRACLE" oil out there! If so, it would be the only brand on the market!
Many "oil seminars" are geared to pushing their brands for increased sales$$$$$$.
Major brand oils are way better than oils of 80 years ago. Pick the brand & viscosity that YOU like and don't try to sell everyone on it, as almost no one is going to change their ways.
Lets just hope no one forgets to change oil regularly.---Bill W.

[Bruce Adams]

as somepne said this has been discussed a thousand times.
Yes, the ZDDP, which has been an additive since the mid 1930's and MIGHT be what kept our engines running, has been greatly lowered since the SJ oils that state "Good for all gasoline engines" in the starburst.
I have read a couple of "engine builders" posts stating the ZDDP was a necessity, and there were valve and/or camshaft failures, but they were self proclaimed ones, not the top five in our hobby.
Myself, I use Shell Rotella which is a diesel grade oil and maintains the ZDDP additive.
I have communicated with Shell chemists and they are strong on recommending ZDDP additive oils for older cars.

[V4F]

i was under the impression that zddp was taken out of all diesel oils by the EPA . not doubting your info . just what i researched ................. steve

[Bruce Adams]

Originally Posted by steve norcal

i was under the impression that zddp was taken out of all diesel oils by the EPA . not doubting your info . just what i researched ................. steve

I just queried Shell today as I had done in the past, and I await their comments on ppm of ZDDP in Shell Rotella T 15W-40.
I will relay their answer.

It seemed to me a couple of years ago it was easy to find Shell Oil touting their ZDDP content on their web site. Not so today.