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ZDDP Additive or Oil-incorporated Does it Work???

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RAC68

RAC68

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Roger Started a thread discussing the best choice of (2) branded ZDDP additives that started me to think …since I had not previously considered ZDDP in any form, why would I consider it now? Doom has been projected every time a formula change is promoted for the fuels or lubricants that we have depended upon for decades, and yet, we still keep rolling on. This thread was created to solicit inputs to the more basic questions about ZDDP and compliment the more advanced objective of Roger’s thread.

In Roger’s thread, Chris explained that our engines require the higher ZDDP content of earlier oil formulations to resist ware in such metal-on-metal contacts as lifter on cam lobe. However, Bob relayed a TV episode that presented the quick destruction of the cam during the initial startup of a newly rebuilt engine even after a ZDDP additive was added to the oil. Finally, Andrea questioned which would be better for our Healey engines when considering that the ZDDP formulated as an additive is different from that which is incorporated in high ZDDP content oils?

So, what does ZDDP do and is it necessary or is it another promotion for the purpose of generating revenue for the supplier? How will it work on our Healey engines? What form of ZDDP will work best on our LBCs? How would you know if you are getting benefit from this costly product?

Your input is appreciated,
Ray (64BJ8P1)
 
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I've been adding ZZDP for 10 to 12 years as oil companies eliminated it. It is a must when first starting an engine after a rebuild. I had my rocker assembly rebuilt and replaced tappets at that time. I started using it then. I think it is a cheap way to hedge the bet. The rocker guy suggested it to reduce wear even after the break-in. Many here use other oils that have it in their formula. Castrol 20-50 does not as most other oils these days. For 8 extra bucks an oil change (once a year for me) I'd be foolish not to. I do not add ZDDP to topping up oil. You can buy it by the case or one by one as needed. Check Ebay for their prices.
 
What I know about what ZDDP does and how it works is this:
On the cam and lifter though the surface looks smooth, there are actually microscopic peaks that look like the Rocky Mountains under a scope. When one of those peaks scrapes the opposing surface it of course gouges and wears the part. Eventually the peak does wear down, but it may have ruined the lifter to the point that it is now rough and will in turn wear the cam lobe, quickly.

During operation at that peak the ZDDP is super heated at the point of metal contact, where it and other stuff like boron then bonds kind of like a solder, to that peak. Since zinc and phosphorous are relatively soft, the next time around the zinc smears and re-bonds, thus preventing the hardened metal from contacting the opposing hardened metal, and instead providing a soft wear surface. If you don't have enough ZDDP then this doesn't happen.

With modern engines and roller lifters this is not a concern at all, so low levels of zinc are ok. Also, the gradual reduction of zinc, phosphorous, sulfer and ash are primarily being done to prevent catalytic converter failure...so for emissions reasons alone.
 
As of May 10, 2013, USA Castrol GTX 20W-50, not Castrol GTX Synblend or any of the other variations, contains between 1% and 5% Zinc alkyl dithiophosphate (ZDDP or ZDTP, take your choice). The MSDS is here: https://msdspds.castrol.com/ussds/amersdsf.nsf/Files/2CC0537054DA605680257B6B00526B55/$File/202242Castrol%20GTX%2020W-50.pdf. The removal of ZDDP from oils is required for lighter grades (10W-30, 5W-20, etc.), but not 20W-50 or other thicker grades because they are not specified for newer cars.
 
About 2 years ago when this came up I did search and the best I could find is that it may help during break-in of new engine. It was either Quaker State or Valvoline who said not necessary. I have never used it with at the peak 5 UK vintage cars and many friends with vintage cars, no one I found ever used it (normal running) and have never heard of damage to engine. It is of course heavily promoted just as many other oil/coolant additive with the "if you don't use it your car's engine will soon scatter itself over the highway." Kind of like if you don't use our deodorant and drink our beer get ready for a life of celibacy. More to the exact, point, anyone know of someone in an otherwise sound engine who has ever experienced damage due to using modern oils?
Jay, '65 3000
 
When I rebuilt my engine I did a lot of reading about this and talked to some pretty knowledgeable automotive engineers. My information pretty much agrees with with Chris said. The zinc is necessary to provide a slippery surface on flat tappet engines. It is particularly necessary during break-in, but less necessary in subsequent oil changes because the slippery surface lasts for a while.

The extra cost of using a zinc-containing oil is trivial, and as far as I know it can't hurt.
 
John Turney said:
As of May 10, 2013, USA Castrol GTX 20W-50, not Castrol GTX Synblend or any of the other variations, contains between 1% and 5% Zinc alkyl dithiophosphate (ZDDP or ZDTP, take your choice). The MSDS is here: https://msdspds.castrol.com/ussds/a...6B00526B55/$File/202242Castrol GTX 20W-50.pdf. The removal of ZDDP from oils is required for lighter grades (10W-30, 5W-20, etc.), but not 20W-50 or other thicker grades because they are not specified for newer cars.
Click to expand...

Thanks for digging out that information John, I have to wonder if most if not all 20W-50 Wt. non synthetic oils on the market, such as Quaker state Vavoline or even the Walmart brand 20w-50 wt. share the same blend or comparable percentage of ZDDP/ZDTP as the Castrol GTX 20W-50 For the exact same reason that these heavy oils where never intended for use in today's modern vehicles.
 
A big problem in initial start up on a new rebuild is, too low RPMs and too short break in time. Manufactures pre lube on cam and lifters, rotate engine as little as possible to set ignition timing before setting the rocker arms and putting pressure on the cam lobes. I never set the rockers until it's ready to fire up! When it's ready to fire up, immediately take it to 2000 RPMS and leave it there for at least 30 minutes. I've done a lot of old Ford flat heads this way and never wiped a cam yet and they also were known for wiping cams! Every engine I've broke in also had a full dose of STP in it. I've used STP in my engines for over 50 years and never had it fail me yet. To much emphasis is placed on zink additives which seems to be the trend these days. I use Valvoline VR-1 20/50 in my cars and that's all they get. My Chevy truck and my Ford Ranger truck gets the same oil, yes 20/50! 345,000 miles on my Chevy 350 and other than normal maintenance, it's never been touched since new and uses 1 Qt oil in 4,000 miles. The new Jeep Liberty gets Valvoline 10/30. For whatever it's worth. PJ
 
tahoe healey said:
I've been adding ZZDP for 10 to 12 years as oil companies eliminated it. It is a must when first starting an engine after a rebuild. I had my rocker assembly rebuilt and replaced tappets at that time. I started using it then. I think it is a cheap way to hedge the bet. The rocker guy suggested it to reduce wear even after the break-in. Many here use other oils that have it in their formula. Castrol 20-50 does not as most other oils these days. For 8 extra bucks an oil change (once a year for me) I'd be foolish not to. I do not add ZDDP to topping up oil. You can buy it by the case or one by one as needed. Check Ebay for their prices.
Click to expand...

ZDDPlus comes in a 4oz bottle. When you change your oil how much ZDDPlus do you add?
 
I recommend anyone interested in oils enough to have this discussion to watch the three or four Mobil 1 fully synthetic myth debunkers on Youtube. I have their 10-60 for old engines in my Healey as a result. I've had fully synthetic in my Bentley since 1998 when R-R recommended it for all their engines after a rebuild. Now we know you can switch rebuild or not.
 
Roger, I've been dumping in 4 oz at oil change of 6 qts. Not a new engine (50 years old yesterday) or rebuild so I feel it is plenty compared to nothing.
TH
 
tahoe healey said:
Roger, I've been dumping in 4 oz at oil change of 6 qts. Not a new engine (50 years old yesterday) or rebuild so I feel it is plenty compared to nothing.
TH
Click to expand...

ZDDPlus says 4oz for 5 quarts. I believe the BJ8 Healeys hold 7 quarts. Although when I change my oil, it seems only 6 to 6 1/2 quarts is pored to fill it back up.
I want to use the recommended amount, but not sure exactly how many ounces that would be, so I use a bottle and a half. I feel a little over is better than not the recommend amount. I buy it for about $7 a bottle. Cheap insurance.
 
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Valvoline VR-1 20W50 Racing Oil and forget about additional additives as it already has all the ZDDP etc that will ever be needed.
 
EV2239 said:
I recommend anyone interested in oils enough to have this discussion to watch the three or four Mobil 1 fully synthetic myth debunkers on Youtube. I have their 10-60 for old engines in my Healey as a result. I've had fully synthetic in my Bentley since 1998 when R-R recommended it for all their engines after a rebuild. Now we know you can switch rebuild or not.
Click to expand...
Stampa-001.jpgStampa-002.jpgconfirmed ZDDP 1200/1300 in the most technologically advanced oil -right for air cooled Porsche- but probably also for our AH
 
ttrotter said:
Valvoline VR-1 20W50 Racing Oil and forget about additional additives as it already has all the ZDDP etc that will ever be needed.
Click to expand...

Is this oil readily available and where ?
 
extract from https://zddplus.labecon.com/TechBrief13%20-%20Oil%20Viscosity.pdf
Conclusions on Picking Oil Viscosity
Most engine oil pumps are of the positive displacement gear type, and assuming the inlet is not starved, they will pump
similar volumes of oil at any given rpm whether the oil is cold or hot. The amount of power required to pump this volume
will vary proportionally with temperature. This means the pressurized bearings in the engine will still get oil even at the
lowest pumpable temperature. Being cold the oil will be highly viscous, protecting the bearings from wear. The biggest
risk with thick, cold oil near the minimum pumping temperature is insufficient ring lubrication, due to the oil being too
viscous to splash onto or flow correctly on cold cylinder walls.
The primary factor to consider when choosing an oil is the manufacturer’s recommendations for the normal (non-W)
viscosity and thermostat temperature. The combination of the two establishes an operating viscosity which is a critical
design criterion for many engine systems. Changing the operating viscosity is not advisable! Of course, heavy-duty,
Arctic or other operation not covered under the original design of the vehicle may dictate a different approach.
If your vehicle was designed to use a 10W-30 oil, the use of a 0W-30 oil will give similar oil viscosity at operating
temperatures, but allow for superior lubrication on start and warm-up. Many older cars were made before the recent
development of multi-viscosity oils with a 0W or 5W rating, but can greatly benefit from their use. This principle applies
even more strongly to cars which were specified with 20W-40 oils. The use of 0W-40 oil will give similar viscosity at
operating temperatures. At extreme cold temperatures 0W-40 will be as little as one eighth as viscous as 20W-40. This
will assure superior lubrication until the engine is warmed up.
 
Healey Nut said:
Is this oil readily available and where ?
Click to expand...
NOTE tat on ZDDP Plus site the use of RACE oils aren't recommended
Why Can’t We Use Racing Oils?
There are some racing oils which maintain a level of ZDDP. Racing oils are optimized for short term severe duty, in contrast to an oil that has been designed for day in, day out street operation. The additive package in a racing oil does not have the same detergent characteristics which are designed into extended service oils. As a result, racing oils may not have the capability of neutralizing acids and keeping contaminants in suspension. Also, the breadth of choice of viscosity, so important to correct street engine operation over a broad temperature range, is not available in racing oils.
By using ZDDPlus™ in addition to a modern high-quality oil of the proper viscosity for your gasoline engine, the correct EP lubrication level is established, and the oil characteristics remain optimized for your engine.r engine
Why Can’t We Use Racing Oils?
There are some racing oils which maintain a level of ZDDP. Racing oils are optimized for short term severe duty, in contrast to an oil that has been designed for day in, day out street operation. The additive package in a racing oil does not have the same detergent characteristics which are designed into extended service oils. As a result, racing oils may not have the capability of neutralizing acids and keeping contaminants in suspension. Also, the breadth of choice of viscosity, so important to correct street engine operation over a broad temperature range, is not available in racing oils.
By using ZDDPlus™ in addition to a modern high-quality oil of the proper viscosity for your gasoline engine, the correct EP lubrication level is established, and the oil characteristics remain optimized for your engine.r engine
 
Andrea,

Note that some of the oils available in Europe are not available in the US, or the formula is different. Syntec is no longer available in the US. Our Castrol synthetic oil is now called Edge.
 
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