ZDDP

Discussions related to motor & gear oils, greases, anti-freezes, etc.
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Al Pressman
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Joined: Mon Jul 06, 2009 12:34 pm

ZDDP

Post by Al Pressman » Mon Apr 12, 2010 12:42 pm

Just curious how many Packard owners are adding ZDDP to the oil. If you are, please say what engine you have and to what type oil you are using.

Al

Adam
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Re: ZDDP

Post by Adam » Wed Apr 14, 2010 7:44 am

What is ZDDP? and by the way, I am not using it !!
"Do not underestimate the English cousin.....they are not as stupid as they look!" - Signor Altabani in The Italian Job.

Dave Czirr
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Re: ZDDP

Post by Dave Czirr » Wed Apr 14, 2010 8:02 am

I'm a bit too lazy to look it up, but I believe zincdiallyldithiophosphonate (or perhaps phosphate) is correct or nearly correct. In varying but small amounts it's been in most better motor oils since the 50s and until recently in relatively higher amounts in the SAE15W-40 heavy duty oils.

JWL115C
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Re: ZDDP

Post by JWL115C » Wed Apr 14, 2010 8:30 am

Probably overkill, but in my '37 Six and '47 Custom I am using Classic Car Motor Oil, 15W-40, made by DA Lubricants and sold by a regional chapter of the Classic Car Club of America. It is a specially formulated oil with added zinc and other additives like were in older oils.

I believe there may be a problem using modern oils during the initial break-in period in newly rebuilt flat tappet engines with new or resurfaced lifters and new or reground camshafts. After that, modern oils should work just fine.

Roller tappet or cam follower engines, like the Packard V-12s and old style straight-8s, should have no problem with modern oils.

(o{I}o)

jacko
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Re: ZDDP

Post by jacko » Wed Apr 14, 2010 5:12 pm

For engines with flat tappets which ride directly on the cam lobes, I suggest using the "Classic Car Motor", 15w40 formulated by DA lubricants in Indianapolis. I use it in my 1940 110 six and my 1933 1002 eight. The eight uses the roller tappets and it is probably not as critical to use on the roller tappet engines since the scuffing on roller tappets in not as severe as on flat tappet followers. However, I use the reformulated oil which contains a zinc content at least as high as the "back-in-the-day" oil originally used in our Packards as supplied by DA Lubricants.
Bob

Adam
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Re: ZDDP

Post by Adam » Thu Apr 15, 2010 12:01 am

Ah, now I know what ZDDP is. The latest oil formulations over here have had the zinc and ash removed to protect exhaust catalysts. But older formulations are still available. My everyday car has a 5/50 wonder creation in it, although full synthetic is really not necessary unless you are going for extended drain intervals. Other moderns that i deal with get a 15w40 heavy duty oil, that serves just fine for petrols and diesels alike.

For my less "old" engines, (I have a Sunbeam Tiger with the Ford 289 V8) I use a standard 20w50 oil. For older engines without full flow, or any, oil filtration, detergents that hold deposits in suspension are less desirable, it is better for the particles to sink to the bottom of the sump, so I use a non-detergent mono-grade SAE 30 oil, and change the oil regularly. Regularly means once each year, unless racing, then it is every race meeting.
"Do not underestimate the English cousin.....they are not as stupid as they look!" - Signor Altabani in The Italian Job.

Steve_Mack_CT
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Location: Central CT Area

Re: ZDDP

Post by Steve_Mack_CT » Tue Nov 30, 2010 1:18 pm

This topic has been discussed extensively on other forums. After reading it all I think I will add ZDDP via the STP treatments available at Le Walmart. Less than $3.00 - cheapest additive I have seen featuring ZDDP and while it also appears to be a thickening agent I am less concerned as the amount is nominal and my car had some miles anyway and is probably not too far from needing the valves serviced. I get a little smoke at start and under hard acceleration but it is running really well with seasonal use less than 1,000 miles each year so far. Regardless I cannot see the STP additive having any material change on the thickness of 6 or more quarts of oil in a Packard 8. I think the potential benefits outweigh any trouble and I have not really heard of any negatives associated with the STP additive although I am not a real advocate of additives in general.

That said is anyone running or contemplating the new Castrol Syntec 20-50 with ZDDP which I understand is designed specifically for antique cars? Seems I have heard something related to drawbacks with using a synthetic oil on older cars but so much has been printed, posted and said regarding oils I really cannot articulate what the issues are. ALso, I understand the Syntec may be somewhere between a full synthetic and a conventional oil but again, I am not 100% sure.

Adam, as an aside I use Syntec 5-50 in our new Audi - I initially read the manual twice as I had never heard of such an oil, but Castrol and I am sure others produce it.

Adam
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Re: ZDDP

Post by Adam » Wed Dec 01, 2010 1:49 am

Not many oils are actually 100% synthetic. Whilst the most expensive ones may be, many are semi-synthetic, meaning that they still use a mineral oil as the base oil and then have a substantial synthetic additive pack, which will contain many elements depending on whether it is blended for petrol or diesel, new or old engine applications. (Typical elements are anti-foaming agents, friction modifiers, detergents (especially for diesels) and others).

There is a great deal of myth and legend regarding oil types. I believe that there are only a few factors that are important for antique cars, given that they are low output engines (relatively), run slowly and are driven protectively (in general). I am afraid that some of the stuff I read is expounded by folk with too much time on their hands. ;)

The only benefit of a synthetic base oil is that it "stays in grade" for (much) longer than a mineral oil since the molecules do not get mashed up. The lubrication value is no different for the same viscosity, that is dependent on the additive pack, which is tailored to the engine type.

It is good to remember that almost all oils are better than those of old. Perhaps key considerations for an old engine are whether it has bore and valve wear or accumulated muck inside. Also whether it has full flow filtration. All of these factors would point to the need to avoid high detergents, as these will hold dirt (carbon) in suspension whilst it would be better to let it settle in the bottom of the sump.

Another factor is the machine tolerances in an old engine (and oil pump) which may be slacker than those of today. For this reason a higher viscosity (SAE 30) may be desirable. The one caveat here is that engines with hydraulic valve lifters sometimes need lower viscosity oil.

Modern oils have had some of the friction modifiers changed for other components. This is because sulphur, and ash can poison catalytic convertors and diesel oxidation catalysts. Whilst this may seem like a problem for older engines, particularly those with sliding contact surfaces (flat tappet tops) other substances are used to replace the problem ones.

It is wise to consider the type of usage our older cars get. If they do no more than a few thousand miles per year and have the oil changed regularly (annually?), then there is no need for the extended drain qualities of a synthetic oil, nor the high detergent properties of a diesel oil.

For these reasons, I use a monograde low detergent SAE 30 "classic" oil in my vintage cars, including the recently rebuilt 6c 1500 Alfa. The 66 Sunbeam Tiger (Ford 289 engine) gets a standard 20/50 (it has full flow filtration), whilst moderns get a 15W40 detergent oil suitable for petrol and diesel alike (high detergent). The one exception is my 2005 Range Rover (Ford V6 diesel engine) which uses a 5W50, I think out of defference to the lifters and the turbo.

I am not a brand snob and use a generic, but good quality trade brand from my local motor factor in 25 litre drums. When I used to run a fleet of modern vehicles, I used a locally blended bulk oil for 15 plus years with never a problem. I do believe that with the "leading brands" you are paying for the marketing as well as the product.

I am sure I have forgotton some factors above and may have to edit later. I have also avoided getting too techy with oil standards from ACEA, MIL or SAE, that is for another day. Meanwhile I shall run for cover as the brickbats fly over this contentious subject !!!!!

Adam..
"Do not underestimate the English cousin.....they are not as stupid as they look!" - Signor Altabani in The Italian Job.

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